WEBVTT

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Prof: So we know
something about all these

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powerful tools that had been
developed: quantum mechanics

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around 1925, '26 actually;
and then all these much more

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modern things,
including scanning probe

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microscopy, which is really
quite recent.

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But the most powerful tool in
organic chemistry,

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for everyday practice,
and certainly for anybody who's

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not a professional chemist and
into quantum mechanics and stuff

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like that, is bonds;
this amazing invention of

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bonds, and how people knew what
things were like before any of

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these tools were dreamt of.

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Right?

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And, for that,
we go back in time and look at

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these guys in the nineteenth
century who invented it.

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And we begin with what's called
-- whoops -- we begin with --

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sorry, here we go again -- okay,
we begin with the Chemical

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Revolution.

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Right?

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That's a name that historians
of science have given this

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period, beginning with
Lavoisier.

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So really that's where we'll
start.

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But he didn't just spring from
nowhere.

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There was a long tradition of
some kinds of chemistry before

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that, and we're going to just
review that very briefly.

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There's a background in ancient
art and lore.

01:21.049 --> 01:21.819
Okay?

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So, for example,
here's a mosaic from Montreale,

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in Sicily, of Noah,
as making wine and then falling

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victim to it and having his
shame hidden by his sons.

01:36.780 --> 01:37.570
Okay?

01:37.569 --> 01:39.459
And here's his flask, right?

01:39.459 --> 01:41.109
Student:  Oh no.

01:41.110 --> 01:44.900
Prof: This is like 3000
years ago.

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The mosaic is about 1000 years;
it's twelfth century,

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it's 800 or 900 hundred years
old.

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Okay?

01:52.190 --> 01:58.220
Here is a Roman glass perfume
vial, that's 2000 years old.

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So they made perfume,
obviously, and extracted the

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stuff from flowers and whatever
that would do that.

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Okay?

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There's the Chemical Research
Building when it was five days

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old.

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Okay?

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And we already saw Francis
Bacon who said:

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"All the philosophy of
nature which is now received,

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is either the philosophy of the
Grecians,

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or that of the alchemists."

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So the alchemists are in a
sense our ancestors.

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He didn't have a very high
opinion of them.

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He said: "The one is
gathered out of a few vulgar

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observations"
(that's the Greek philosophers)

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"and the other out of a few
experiments of a furnace.

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The one never faileth to
multiply words,

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and the other ever faileth to
multiply gold."

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So even at this time,
when science was beginning to

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get underway,
modern science,

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alchemy was already in
disrepute.

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But it did contribute some
things.

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It didn't contribute much to
theory, because the theory

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depended on Greek,
well on the Greek antecedents

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and authority,
rather than observation.

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But they did fiddle around.

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Here's a painting of an
alchemist from 1663.

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And remember,
Newton did more work in alchemy

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than he did in physics.

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Right?

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And he wrote an enormous amount
but never published anything

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about it.

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There's a great website now,
from the University of Indiana,

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of all Newton's alchemical
works, and you can look at them.

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But this was to be kept a
secret.

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That was the idea of alchemy,
that it was occult,

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it was hidden.

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Okay?

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And in fact there's a show
that's coming up on alchemy at

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the Beinecke Library,
in January, of their holdings

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in alchemy,
and the title of the show is

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"The Book of Secrets."

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Right?

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And that's Harry Potter
as well, right?

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>

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So here's one of the things
that's going to be shown.

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It's part of a really long
scroll, which is the Visio

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Mystica of Arnold of
Villanova,

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who was a thirteenth century
alchemist who was into medicine

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and was considered the greatest
medical authority of its time.

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This particular scroll was
written in England in 1570.

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So a lot of it's in English.

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It says, "the red sea,
the red lune ,

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the red sol ."

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Right?

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All sorts of mystical things.

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And then, and you see here is
the corpus, the body,

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which is earth;
and here's the soul,

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which is oil;
and here's the spirit or the

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air, the breath,
which is water.

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So there was -- everything was
a symbol for something else.

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Or if you look at the four
corners of this,

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on the bottom right we have
air.

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Right?

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"Eeyre",
it says, "is hott and

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moyst."

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Right?

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Or on the top left is earth,
which is cold and dry;

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the opposite of air.

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And down here is fire,
which is hot and dry.

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And up there is water,
which is cold and moist.

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Right?

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So this was supposed to be
something profound and

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mysterious.

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Another thing they're going to
show is this book,

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On the Philosopher's
Stone, which was written in

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the thirteenth century.

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The particular copy they have
is from 1571.

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But it looks like somebody's
organic chemistry text,

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after they've highlighted it in
preparation for the exam.

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Every word is underlined.

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>

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Right?

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And all in the margin are these
fingers pointing to important

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things.

05:45.728 --> 05:46.298
Right?

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And if you look there,
you'll see great words like

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alchemy there,
you see elixir.

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I forget, there are a lot of
key words.

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But fundamentally it's all
nonsense, all the theory.

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The reason people kept it
secret, really,

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was, I think,
not to keep other people from

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finding it out,
but to hide the fact that it

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was nonsense.

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That's just my own theory,
so maybe that's wrong.

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Okay, but Paracelsus,
in the early 1500s,

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was an alchemist,
a traveling physician,

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and he developed what had been
long before that,

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which was the Doctrine of
Sympathies,

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and one aspect of that was in
nature,

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antidotes for poisons are to be
found near the source of the

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illness.

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Right?

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So, for example,
you know what that is?

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Student:  Poison ivy.

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Prof: Poison ivy. Right?

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But near poison ivy you're
likely to find jewelweed,

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which is an antidote for poison
ivy.

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Right?

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Or -- poison ivy is a New World
thing, so that didn't interest

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the alchemists -- but this one
certainly did.

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Willow -- Salix is the Latin
name for willow -- which is

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found in malarial swamps.

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So you go into a swamp,
you get malaria,

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but you also find the willow
there.

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And the willow bark,
extracting from the willow bark

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you can get Salicin,
a glycoside,

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which is a sugar plus an
aromatic thing there.

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Right?

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And if you hydrolyze that to
get the sugar off,

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and oxidize that to make a
carboxylic acid,

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you get this.

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What's that?

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Students:
Salicylic acid.

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Prof: Right.

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Salicylic acid,
from alix.

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Right?

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So it's good for fevers and so
on, for your malaria.

07:41.209 --> 07:44.079
Okay, so that's a theory.

07:44.079 --> 07:45.609
This is another thing they're
going to show,

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a Vade Mecum -- come
along with me --

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which is a lab manual that was
kept by Caspar Harttung vom

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Hoff,
in 1557, in Austria.

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So you can see he draws various
-- what he's,

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he's reading various things,
and writing extracts and notes

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to himself about it.

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It's like your pre-lab
preparation.

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Right?

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Okay, and you notice who he's
quoting up here?

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Arnold, that guy from the
thirteenth century who did the

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thing we've showed first.

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Right?

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Arnold of Villanova.

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Okay, but he shows distillation
apparatus.

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These things are called
pelicans.

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Isn't that interesting?

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And here's a lamp.

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And here's somebody,
he's filtering something

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through some kind of screen or
grid there.

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Okay?

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So they developed tools that
were of great use to chemistry,

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once chemistry got going.

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So there was a lot of -- even
though the theory was nonsense

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-- there was a lot of practical
background in preparing various

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elixirs and so on.

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So this was crucial.

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Now here is a lab that could
easily be mistaken for an

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alchemical laboratory,
but in fact it's an early

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chemical laboratory.

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And I'll show it to you here.

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It's this book,
it's this picture here from

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1777, from a book about Air
and Fire.

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And it reports the discovery of
a new element,

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in this book.

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And it's by Carl Wilhelm
Scheele, who was in Uppsala;

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"Upsala", in Sweden.

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What do you think he discovered
with light and fire -- or pardon

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me, with air and fire;
Luft und dem Feuer?

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Student:  Oxygen.

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Prof: Ah ha, we'll see.

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So that's his laboratory,
Scheele's laboratory,

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or at least some artist's
impression of it.

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And here he is.

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He's before the Chemical
Revolution, but he's an

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important precedent,
as you'll see,

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to the Chemical Revolution.

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He was by practice a pharmacist
but he spent most of his time

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doing what is really chemical
research.

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Here's a picture of a stamp,
a Swedish stamp,

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showing Scheele.

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Except it's not Scheele.

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It turns out the costume he's
wearing wouldn't have been

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developed until forty years
after Scheele died.

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Okay, but he purified organic
compounds, that weren't easy to

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purify;
in particular, carboxylic acids.

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So he got an acid from -- that
he called lactic acid;

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which we now know has that
structure.

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Where did he get it?

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<<Students speak over one
another>>

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Prof: From sour milk.

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Okay?

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So here's his paper about that,
"On Milk and its

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Acid" from 1780.

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So he purified these acids as
salts that he could crystallize.

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That was the method of
purifying.

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So here's several reports in
that paper.

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Item 7: "Bismuth, cobalt,
antimony, tin,

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mercury, silver and gold were
attacked by lactic acid,

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either by digestion"
(that's just sitting there

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under it) "or by boiling.

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After standing over tin,
the acid caused a black

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precipitate to form in a
solution of gold and aqua

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regia." Right?

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So this is not mysterious
writing.

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Right?

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It's talking in language that
we can understand,

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even though it's translated
from German.

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Iron and zinc were dissolved
with a formation of flammable

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air.

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What do you suppose -- he
reacted acid with zinc and he

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got flammable air.

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What do you suppose that was?

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Student:  Hydrogen gas.

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Prof: Hydrogen, right?

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"The iron solution was
brown and gave no

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crystallization,
but the zinc solution

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crystallized."

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Why was that important?

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Student:  He could
purify it.

11:50.908 --> 11:53.648
Prof: Because he could
purify it if it crystallized,

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and get just that salt.

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Right?

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So that's how he got pure
samples of acids.

11:57.855 --> 11:58.365
Right?

11:58.370 --> 12:00.750
"With copper,
our solution first took on a

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blue color, then green,
finally dark blue,

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but did not crystallize";
unfortunately.

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And 10: "Lead dissolved
after several days of digestion.

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The solution acquired a sweet,
tart taste,"

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>

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"but did not
crystallize."

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Right?

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So what do you do when you
don't have IR and NMR,

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right?

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Student:  Eat.

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Student:  Taste.

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Prof: Sure.

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So he tasted all these things.

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Cyanide too.

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Okay, so he got citric acid.

12:29.549 --> 12:31.279
Where did he get that?

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Student:  Lemons.

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Prof: From lemons, okay?

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And he got uric acid;
obvious.

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He got tartaric acid.

12:42.120 --> 12:44.510
Tartaric acid,
his discovery,

12:44.514 --> 12:48.534
turns out to one of the --
probably the single most

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important,
maybe the second,

12:50.129 --> 12:52.729
no probably the most important
compound in the nineteenth

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century,
as you'll see.

12:55.159 --> 12:55.549
Okay?

12:55.548 --> 12:58.968
That comes from tartar,
which is the deposit on the

12:58.971 --> 13:02.531
inside of wine casks,
after you've fermented wine.

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Okay?

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Benzoic acid came from gum
benzoin, a product of the Far

13:09.046 --> 13:09.806
East.

13:09.809 --> 13:10.709
Okay?

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And oxalic acid.

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Where do you think that came
from?

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It came from rhubarb.

13:21.590 --> 13:25.330
Now why oxalic;
why oxy?

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Oxy means sharp.

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So what does sharp have to do
with it, with rhubarb?

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Student:  It has a sharp
taste?

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Prof: Yes,
so you know oxy as a

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root, meaning sharp.

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Oxymoron doesn't mean a stupid
ox.

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What it means is sharp,
and moron means dull.

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So it's a sharp dullness,
is an oxymoron.

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It's a self-contradictory word.

13:56.825 --> 13:57.535
Right?

13:57.539 --> 14:01.839
So what's sharp about rhubarb?

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Student:  Its taste.

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Prof: Its taste;
it tastes acidic.

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In fact, the word acidic
comes from the Latin

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acidus;
which comes from acre,

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to be sour;
which comes from,

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the root is ac,
which means sharp.

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So it's the same thing,
acid and oxy.

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Okay?

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So look at all these things.

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They have what?

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The carboxylate group,
which makes them acidic.

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Right?

14:25.210 --> 14:26.670
And we know why it makes it
acidic;

14:26.668 --> 14:29.508
this is a review from last
time, this functional group.

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It's not a carbonyl alcohol,
it's a carboxylic acid.

14:33.990 --> 14:37.210
The high HOMO is stabilized in
the acid.

14:37.210 --> 14:40.170
But it's even more stabilized
when it's an anion,

14:40.172 --> 14:42.212
because you have a higher HOMO.

14:42.210 --> 14:47.100
So it changes the acidity,
the ease of dissociation of

14:47.102 --> 14:49.692
H^+, by a factor of 10^11th.

14:49.687 --> 14:50.517
Right?

14:50.519 --> 14:54.829
Which depends on the energy
difference between those two.

14:54.830 --> 14:58.860
So if you more stabilize the
anion product than you stabilize

14:58.860 --> 15:02.150
the starting material,
then you shift the reaction

15:02.150 --> 15:04.230
toward product,
here by 10^11th;

15:04.232 --> 15:05.512
a big change.

15:05.509 --> 15:06.939
Okay?

15:06.940 --> 15:09.830
But actually there's more to it
than just that resonance,

15:09.832 --> 15:11.592
just that HOMO/LUMO
interaction.

15:11.590 --> 15:14.490
There's a thing called
"inductive effects"

15:14.491 --> 15:16.371
that we'll talk about later on.

15:16.370 --> 15:19.300
But a large part of it is due
to that.

15:19.298 --> 15:21.938
Okay, but you notice there's
one exception here.

15:21.940 --> 15:33.650
Uric acid doesn't have a
carboxylate group in it.

15:33.649 --> 15:35.529
So there's what it has.

15:35.529 --> 15:40.059
And notice that it has an
unshared-pair on nitrogen.

15:40.058 --> 15:43.068
Like an amide,
it's stabilized by a carbonyl;

15:43.070 --> 15:48.080
in fact, it's stabilized by two
carbonyls, two adjacent LUMOs to

15:48.077 --> 15:49.267
stabilize it.

15:49.269 --> 15:53.629
Now if that were just stable,
it wouldn't be a reason to get

15:53.625 --> 15:55.835
rid of it, to lose a proton.

15:55.840 --> 15:59.170
But the anion that you get if
you lose the proton from

15:59.174 --> 16:01.004
nitrogen has a higher HOMO.

16:01.000 --> 16:03.140
So it's even more stabilized.

16:03.139 --> 16:06.649
The same trick as in carboxylic
acid, but even more so,

16:06.653 --> 16:08.023
as you'll see here.

16:08.019 --> 16:11.579
The pK_a of this compound is
5.8.

16:11.580 --> 16:13.390
It's pretty acidic. Right?

16:13.389 --> 16:18.209
But a normal amine,
like ammonia losing a proton,

16:18.208 --> 16:19.918
has a pK_a of 38.

16:19.916 --> 16:20.816
Right?

16:20.820 --> 16:24.430
So this is thirty-two powers of
ten helped out,

16:24.426 --> 16:28.106
because it has such a high HOMO
on the nitrogen,

16:28.110 --> 16:31.090
and two carbonyls to stabilize
it.

16:31.090 --> 16:36.490
Okay, so uric acid is indeed an
acid, like carboxylic acids.

16:36.490 --> 16:40.010
Okay, now Scheele not only did
these organic acids,

16:40.009 --> 16:42.539
he also discovered,
or co-discovered,

16:42.542 --> 16:43.882
seven elements.

16:43.879 --> 16:46.499
They're listed here according
to what row of the periodic

16:46.500 --> 16:47.390
table they're in.

16:47.389 --> 16:51.449
Notice down at the bottom here
you have tungsten.

16:51.452 --> 16:52.132
Right?

16:52.129 --> 16:53.909
Tungsten comes from Swedish.

16:53.909 --> 16:54.759
He was Swedish.

16:54.759 --> 16:56.209
It's "tung"
"sten",

16:56.206 --> 16:56.736
heavy stone.

16:56.740 --> 16:59.870
Being way down,
it's got lots of protons and

16:59.870 --> 17:02.200
neutrons and is very,
very dense.

17:02.201 --> 17:02.931
Right?

17:02.928 --> 17:05.808
So it's heavy -- the stones
that it comes from are very

17:05.808 --> 17:06.128
heavy.

17:06.130 --> 17:06.610
Right?

17:06.608 --> 17:10.828
But by contrast,
these up here are gases.

17:10.828 --> 17:15.968
And in fact that's what got the
19th Century chemistry going.

17:15.970 --> 17:18.700
That's what launched the
Chemical Revolution,

17:18.695 --> 17:20.985
was the ability to work with
gases.

17:20.990 --> 17:24.780
Because to be a gas,
something has to be a small

17:24.775 --> 17:29.845
molecule and therefore simple,
or at least relatively simple.

17:29.848 --> 17:33.488
So you had to start with simple
things before you could get the

17:33.490 --> 17:35.430
complex ones,
like salicylic acid,

17:35.428 --> 17:37.188
in terms of understanding.

17:37.190 --> 17:40.500
Now Scheele,
in 1771, had heated silver

17:40.499 --> 17:45.289
carbonate, and he found that he
got CO_2 out of them;

17:45.288 --> 17:48.798
he didn't know it was CO_2,
but the gas came out.

17:48.799 --> 17:50.509
Okay?

17:50.509 --> 17:55.249
And if you heated that still
more, greater than 340 Celsius,

17:55.249 --> 17:58.859
then you get silver,
and oxygen comes out from

17:58.864 --> 18:02.364
silver oxide;
this gas, this

18:02.355 --> 18:06.605
feuerluft,
fire air.

18:06.609 --> 18:08.599
That's what the book is about.

18:08.599 --> 18:09.439
Okay?

18:09.440 --> 18:12.750
So he wrote the book.

18:12.750 --> 18:17.870
But the book starts,
as I'll show you here --

18:17.868 --> 18:21.108
sorry, there we go -- the book
starts with an introduction,

18:21.108 --> 18:26.688
a
"vorbericht",

18:26.690 --> 18:29.440
which is translated,
it says, from Swedish.

18:29.440 --> 18:31.860
And let's see where it says
here.

18:31.858 --> 18:36.348
And it's by Torbern Bergman,
written in 1777.

18:36.348 --> 18:40.778
He had this book written for
two years, waiting for this

18:40.779 --> 18:42.229
preface to come.

18:42.230 --> 18:45.030
Bergman was a busy guy. Right?

18:45.029 --> 18:47.979
And during the time that this
book was sitting,

18:47.980 --> 18:51.380
ready, the manuscript was
sitting ready to be printed,

18:51.382 --> 18:54.272
Priestley, in England,
discovered oxygen.

18:54.269 --> 18:56.569
So this book came out after
Priestley.

18:56.568 --> 19:01.948
But there's no doubt that
Scheele had discovered it

19:01.952 --> 19:03.032
earlier.

19:03.029 --> 19:05.269
His lab books from 1771 show it.

19:05.269 --> 19:10.759
And here, in 1774,
is his draft of a letter that

19:10.757 --> 19:13.207
he wrote to France.

19:13.210 --> 19:16.420
And it begins -- or it actually
begins with a couple of words on

19:16.424 --> 19:18.174
the previous sheet --
but it says:

19:18.174 --> 19:20.674
"…since I have no
large burning glass,

19:20.670 --> 19:22.570
I beg you to try with
yours..."

19:22.568 --> 19:25.508
Because he had to do this by
heating things in an oven,

19:25.511 --> 19:28.401
at a really high temperature,
which was hard to do.

19:28.400 --> 19:31.630
But if you could do it with a
focused light of the sun to heat

19:31.631 --> 19:33.911
it, then it would be much more
practical.

19:33.910 --> 19:38.070
And, in France,
they had such a big magnifying

19:38.071 --> 19:41.311
glass, that would allow to do
it.

19:41.308 --> 19:43.968
But that letter,
although it was sent,

19:43.970 --> 19:45.480
was never answered.

19:45.480 --> 19:50.080
And you know who it was sent
to, presumably.

19:50.078 --> 19:53.758
Lavoisier, the founder of the
Chemical Revolution,

19:53.755 --> 19:56.375
and another discoverer of
oxygen.

19:56.380 --> 19:57.820
Okay?

19:57.818 --> 20:01.518
Okay, so now we're going to
talk about Lavoisier,

20:01.516 --> 20:05.976
who was -- wasn't a perfect
person, but he was really very,

20:05.980 --> 20:07.060
very good.

20:07.058 --> 20:09.658
Okay, now the Chemical
Revolution.

20:09.660 --> 20:14.210
You can say it started in 1789,
the Chemical Revolution.

20:14.210 --> 20:17.350
And that's not the only
revolution that started in

20:17.351 --> 20:18.311
France in 1789.

20:18.313 --> 20:18.893
Right?

20:18.890 --> 20:20.580
Do you know what this is?

20:20.579 --> 20:21.949
What?

20:21.950 --> 20:22.710
Student:  Tennis Court
Oath.

20:22.710 --> 20:23.750
Prof: It's the Tennis
Court Oath,

20:23.750 --> 20:28.230
when the legislators,
so to say, gathered to say that

20:28.228 --> 20:33.048
they wouldn't disband until the
king granted them certain

20:33.051 --> 20:35.681
things;
and you know what that led to,

20:35.675 --> 20:36.175
in 1789.

20:36.180 --> 20:40.530
The only guy that didn't agree
was this guy here.

20:40.529 --> 20:43.429
He's the only one that didn't
sign it.

20:43.430 --> 20:48.030
But at any rate, it was radical.

20:48.029 --> 20:51.539
Now there's an Indo-European
word, that's the root of many

20:51.536 --> 20:55.226
words, called Werad;
and it gives words in all sorts

20:55.234 --> 20:56.104
of languages.

20:56.099 --> 20:59.339
Like it means root.

20:59.339 --> 21:01.119
Okay?

21:01.118 --> 21:03.718
And Wurzel,
in German, means root;

21:03.720 --> 21:05.240
and wort,
like St.

21:05.242 --> 21:06.832
John's wort,
is a root.

21:06.829 --> 21:09.879
Licorice;
glukos rhiza,

21:09.876 --> 21:12.906
Greek, the rhiza is
root;

21:12.910 --> 21:14.070
sweet root it means.

21:14.069 --> 21:14.599
Okay?

21:14.599 --> 21:18.939
Race;
razza in Italian is the

21:18.935 --> 21:20.785
root of your being.

21:20.788 --> 21:21.568
Right?

21:21.569 --> 21:23.909
Rutabaga.

21:23.910 --> 21:29.020
Radix in Latin;
and you know lots of words come

21:29.022 --> 21:31.632
from radix,
like radish is a root.

21:31.630 --> 21:36.360
Or eradicate,
what does that mean?

21:36.358 --> 21:38.668
Prof: It means to pull
it out by the roots.

21:38.670 --> 21:39.590
Okay?

21:39.589 --> 21:42.649
Or radical;
something that's radical is

21:42.654 --> 21:45.964
something that goes right to the
root, back to the very origin of

21:45.958 --> 21:46.628
something.

21:46.630 --> 21:48.770
And that word,
used in that way,

21:48.766 --> 21:51.796
if you look in the Oxford
English Dictionary,

21:51.797 --> 21:55.447
it was coined in mathematics in
the 16th Century.

21:55.450 --> 21:57.830
The root of a number is its
origin.

21:57.828 --> 21:58.388
Right?

21:58.390 --> 22:01.580
If you take the square root of
a number, and multiply it by

22:01.576 --> 22:03.166
itself, you get the number.

22:03.170 --> 22:06.870
So it's the root of the number;
the radical. Right?

22:06.868 --> 22:09.258
Or in politics,
it was used in 18th Century in

22:09.263 --> 22:10.843
England,
and in chemistry,

22:10.836 --> 22:14.006
in 18th Century in France,
the idea of radical as the root

22:14.009 --> 22:15.909
of things,
began to be used;

22:15.910 --> 22:16.920
which we'll see.

22:16.920 --> 22:19.620
Okay, so 1787,
radical was introduced as a

22:19.622 --> 22:22.652
political term,
according to the Oxford English

22:22.653 --> 22:25.623
Dictionary, by J. Jebb,
whoever he was;

22:25.619 --> 22:28.339
presumably a politician.

22:28.338 --> 22:31.088
Or in 1787, there was this
radical document,

22:31.085 --> 22:32.735
"We the People."

22:32.744 --> 22:33.324
Right?

22:33.318 --> 22:37.828
But that same year,
1787, radical was introduced as

22:37.828 --> 22:41.618
a chemical term,
by Louis Bernard Guyton de

22:41.616 --> 22:42.696
Morveau.

22:42.700 --> 22:48.500
And it was in the context of
developing nomenclature for

22:48.502 --> 22:49.772
chemistry.

22:49.769 --> 22:52.689
So he, together with Berthollet
and Fourcroy,

22:52.693 --> 22:56.353
developed a new method for
nomenclature in chemistry.

22:56.349 --> 22:58.059
And here's a book.

22:58.058 --> 23:01.358
This is not the original
French, but it's the first

23:01.358 --> 23:04.528
English translation,
which you see comes from the

23:04.526 --> 23:07.096
Yale University Library,
back when.

23:07.099 --> 23:10.949
It's from 1788.

23:10.950 --> 23:11.410
Okay?

23:11.410 --> 23:14.790
So A Method of Chemical
Nomenclature,

23:14.786 --> 23:18.396
by Guyton de Morveau,
Lavoisier, Berthollet and

23:18.398 --> 23:19.418
Fourcroy.

23:19.420 --> 23:25.190
So the fourth author of this
new method of chemical

23:25.194 --> 23:28.434
nomenclature is Lavoisier.

23:28.430 --> 23:29.950
So there's Lavoisier with his
wife.

23:29.950 --> 23:33.610
This is part of an enormous
picture that's in the

23:33.606 --> 23:34.746
Metropolitan.

23:34.750 --> 23:38.030
It was commissioned by
Lavoisier and his wife,

23:38.030 --> 23:41.240
who hired Jacques-Louis David
to paint it.

23:41.240 --> 23:44.990
And they paid 7000 pounds,
to the artist to paint it;

23:44.990 --> 23:48.380
which is the equivalent of
$300,000 today.

23:48.380 --> 23:50.240
They were quite well-to-do.

23:50.240 --> 23:52.590
They had an income of the order
of a million dollars a year,

23:52.592 --> 23:55.312
or the equivalent;
it depends on how you translate

23:55.309 --> 23:56.549
numbers, of course.

23:56.549 --> 23:57.619
It's hard.

23:57.618 --> 24:02.288
So here he is at the age of 45,
in 1789,

24:02.288 --> 24:05.118
and he's working on drafting --
so these guys,

24:05.118 --> 24:06.688
when they had their portraits
painted,

24:06.690 --> 24:09.310
always put something important
in it.

24:09.309 --> 24:11.019
So what did he choose to have?

24:11.019 --> 24:15.659
He chose to be working on a
manuscript, and the manuscript

24:15.656 --> 24:19.396
he's working on is the
manuscript of this book,

24:19.400 --> 24:20.540
from 1789.

24:23.144 --> 24:26.414
Chimie;
the Elementary Treatise on

24:26.405 --> 24:27.775
Chemistry.

24:27.778 --> 24:34.598
And the other stuff he put in
the picture is the equipment he

24:34.603 --> 24:35.403
used.

24:35.400 --> 24:39.530
So here you see various
equipment from one of the plates

24:39.525 --> 24:41.395
at the end of the book.

24:41.400 --> 24:43.680
And you can see these items in
the picture.

24:43.680 --> 24:45.930
There's that bell jar.

24:45.930 --> 24:50.170
There's that device.

24:50.170 --> 24:56.400
There's that big sixteen-pint
flask, with a brass fitting on

24:56.401 --> 24:56.931
it.

24:56.930 --> 25:01.850
There's that valve that you
attach to the bottom of the

25:01.849 --> 25:02.579
flask.

25:02.578 --> 25:06.138
And over here is a portfolio,
and the portfolio says,

25:06.135 --> 25:09.145
down in the corner,
"Paulze Lavoisier

25:09.145 --> 25:10.715
sculpsit."

25:10.720 --> 25:13.450
That means this was drawn by
Paulze Lavoisier,

25:13.448 --> 25:14.598
who was his wife.

25:14.598 --> 25:18.158
She was his assistant in the
laboratory, kept all the

25:18.157 --> 25:19.917
notebooks;
read English for him,

25:19.923 --> 25:21.453
because he couldn't read
English.

25:21.450 --> 25:23.520
So if he had to do anything
with Priestley,

25:23.519 --> 25:24.849
she would read it to him.

25:24.849 --> 25:25.949
But she drew all these things.

25:25.950 --> 25:29.160
She studied with David,
drawing, in order to be able to

25:29.155 --> 25:29.745
do this.

25:29.750 --> 25:36.860
Okay, she painted this portrait
of their family friend.

25:36.859 --> 25:37.839
Who's that?

25:37.838 --> 25:38.818
Student:  Benjamin
Franklin.

25:38.818 --> 25:40.078
Prof: Yes,
Benjamin Franklin.

25:40.078 --> 25:42.848
I showed you that picture
earlier, said we'd refer to it

25:42.846 --> 25:43.246
again.

25:43.250 --> 25:46.830
So this is that particular
plate in the book,

25:46.830 --> 25:49.680
and it relates to weighing a
gas.

25:49.680 --> 25:54.790
It'll turn out that the most
important thing for Lavoisier,

25:54.788 --> 25:58.798
and for the whole 19th Century
-- all this development that led

25:58.804 --> 26:01.074
to bonds and their arrangement
--

26:01.069 --> 26:03.789
weighing was the key thing.

26:03.789 --> 26:05.709
But how do you weigh a gas?

26:05.710 --> 26:09.510
So you need gases so they're
simple enough to deal with,

26:09.506 --> 26:10.816
and easy to purify.

26:10.817 --> 26:11.437
Right?

26:11.440 --> 26:13.970
But you need to weigh them.

26:13.970 --> 26:16.360
So how can you weigh a gas?

26:16.358 --> 26:19.148
Well you can collect a gas,
as shown in this picture,

26:19.150 --> 26:23.590
by generating it in this retort
G, and it comes and it bubbles

26:23.592 --> 26:26.912
up,
displacing water or mercury,

26:26.910 --> 26:30.200
most often mercury,
from a bell jar.

26:30.200 --> 26:31.840
You've done this kind of thing?

26:31.839 --> 26:31.969
Student:  Yes.

26:31.970 --> 26:33.030
Prof: Some of you.

26:33.029 --> 26:34.149
But you can see how it would
work;

26:34.150 --> 26:35.810
as it bubbles up the mercury
comes down.

26:35.809 --> 26:36.409
Okay.

26:36.410 --> 26:38.130
So now you have the gas.

26:38.130 --> 26:41.440
Now we'll shift attention down
to the bottom right here,

26:41.442 --> 26:42.952
and see how this works.

26:42.950 --> 26:45.420
So we have this bell jar on the
bottom,

26:45.420 --> 26:47.510
which is fitted with valves on
the top,

26:47.509 --> 26:50.529
is filled with mercury,
and it's in a pool of mercury,

26:50.529 --> 26:55.369
and then this big sixteen-pint
flask is evacuated.

26:55.369 --> 26:56.839
You use one of these pumps.

26:56.838 --> 27:01.848
Remember, 100 years before
this, Hooke -- or 130 years

27:01.847 --> 27:07.327
before this -- Hooke made a
great vacuum pump for Boyle.

27:07.328 --> 27:11.628
Boyle is the only person on the
front of the building older than

27:11.632 --> 27:12.322
Lavoisier.

27:12.315 --> 27:12.925
Right?

27:12.930 --> 27:15.750
And that was dealing with gases
and Boyle's Law,

27:15.750 --> 27:18.630
how pressure and volume relate
to one another.

27:18.630 --> 27:22.030
Okay, so anyhow,
he could evacuate that with a

27:22.027 --> 27:25.497
pump, then seal it off,
turn the valves off.

27:25.500 --> 27:26.760
And he's got mercury in that
thing.

27:26.759 --> 27:29.989
And now he puts a tip
underneath it and generates gas.

27:29.990 --> 27:36.360
And it bubbles up and fills
this container with a gas.

27:36.358 --> 27:39.088
And it's sitting in a mercury
pool so that it's not

27:39.086 --> 27:41.916
communicating with the
atmosphere, other than through

27:41.923 --> 27:44.273
the pressure,
through the mercury pool.

27:44.269 --> 27:48.009
Okay, so now he opens the
valves.

27:48.009 --> 27:52.039
So the vacuum starts sucking up
the mercury;

27:52.038 --> 27:55.128
that is, pulling the air in,
up to a certain point.

27:55.134 --> 27:55.634
Right?

27:55.630 --> 27:57.100
Then the mercury stops rising.

27:57.099 --> 27:58.519
Okay?

27:58.519 --> 28:02.789
And now, at this point you know
that the pressure of that gas is

28:02.788 --> 28:06.308
atmospheric pressure,
less whatever the height of the

28:06.314 --> 28:07.534
mercury column is.

28:07.534 --> 28:08.284
Right?

28:08.279 --> 28:11.149
That's how a barometer works.

28:11.150 --> 28:16.740
So he knows how much gas,
what volume of gas he has in A.

28:16.740 --> 28:20.960
He filled it with water first
and weighed it to see what its

28:20.960 --> 28:21.890
volume was.

28:21.890 --> 28:24.230
Now he knows the volume,
he knows the pressure.

28:24.230 --> 28:27.340
So he knows how much gas there
would be, at atmospheric

28:27.335 --> 28:27.845
pressure.

28:27.852 --> 28:28.372
Right?

28:28.368 --> 28:31.408
And now, of course,
he just turns off these things,

28:31.410 --> 28:34.630
unscrews one,
the thing on top,

28:34.633 --> 28:38.633
and weighs it,
and sees how much heavier it is

28:38.625 --> 28:41.065
than it was when it was
evacuated.

28:41.068 --> 28:42.598
And that's how much the air
weighs.

28:42.598 --> 28:45.308
And he knows how much volume,
how much pressure.

28:45.308 --> 28:48.488
So he knows how much whatever
gas he collected weighed.

28:48.490 --> 28:50.390
So he could weigh a gas.

28:50.390 --> 28:53.030
Pretty clever, huh?

28:53.029 --> 28:57.359
Okay, here he is working with
one of these bell jars.

28:57.358 --> 29:02.158
Now these bell jars were filled
with mercury.

29:02.160 --> 29:07.340
I don't know if you've -- here,
would you help me out Wilson?

29:07.338 --> 29:09.428
Lift this up and show it to the
class.

29:09.430 --> 29:13.120
But don't lift it high,
hold it above the thing.

29:13.119 --> 29:14.279
Did it surprise you?

29:14.279 --> 29:14.839
Student:  Yes.

29:14.838 --> 29:17.528
Prof: He said it
surprised him.

29:17.528 --> 29:20.208
And you can come up afterwards,
if you want to,

29:20.205 --> 29:22.995
and be surprised yourself,
by lifting this up.

29:23.000 --> 29:25.470
But keep it over this,
because people are so panicked

29:25.471 --> 29:26.661
about mercury nowadays.

29:26.660 --> 29:28.490
I heard on the way over to
class, while I was bringing

29:28.492 --> 29:30.712
this,
I heard there's a new law in

29:30.710 --> 29:34.870
the European Union that it's
going to be illegal to transport

29:34.866 --> 29:37.496
mercury over international
borders.

29:37.500 --> 29:38.760
Go figure.

29:38.759 --> 29:42.889
Anyhow, there's Lavoisier doing
an experiment with this big

29:42.894 --> 29:44.114
thing of mercury.

29:44.107 --> 29:44.747
Right?

29:44.750 --> 29:47.390
He must've been a stout person.

29:47.390 --> 29:48.350
Okay?

29:48.348 --> 29:52.298
This is him in his library,
with Madame Lavoisier taking

29:52.298 --> 29:55.458
his dictation,
as he does his experiments.

29:58.130 --> 30:02.390
and I'll show you the -- this
actually is a facsimile,

30:02.390 --> 30:04.570
not the real thing.

30:04.568 --> 30:11.168
But here's the title page of
the first volume.

30:11.170 --> 30:12.910
Okay.

30:12.910 --> 30:14.460
So you can look at that if you
want to.

30:14.460 --> 30:16.850
And at the end,
I'll just note here,

30:16.848 --> 30:22.258
at the end of the second
volume, are all these pages,

30:22.259 --> 30:27.479
which are devices -- like
here's this is the one we just

30:27.480 --> 30:28.620
looked at.

30:28.619 --> 30:30.829
Okay?

30:30.828 --> 30:33.168
So if you want to look at them,
feel free.

30:33.170 --> 30:35.290
Don't handle the other one
though;

30:35.289 --> 30:36.919
it's real.

30:36.920 --> 30:40.980
Okay, so Elementary Treatise
of Chemistry,

30:40.980 --> 30:44.540
Presented in a New Order
-- this is the Revolution --

30:44.538 --> 30:46.038
According to Modern
Discoveries,

30:46.039 --> 30:49.789
With Figures;
as I just showed you.

30:49.788 --> 30:55.618
And 1789 is the date,
the same as the French

30:55.617 --> 30:57.377
Revolution.

30:57.380 --> 31:00.060
Okay, you notice he's a member
of all different academies,

31:00.063 --> 31:01.243
including Philadelphia.

31:01.240 --> 31:03.500
Why in the world would he have
been a member of the Scientific

31:03.503 --> 31:04.473
Academy of Philadelphia?

31:04.470 --> 31:06.020
He never went there.

31:06.019 --> 31:06.679
Student:  Ben Franklin
was --

31:06.680 --> 31:08.630
Prof: Right, his pal.

31:08.630 --> 31:10.080
Okay, 1789.

31:10.078 --> 31:12.848
So it has the most wonderful
Introduction,

31:16.230 --> 31:18.720
And he says:
"My only object,

31:18.720 --> 31:22.250
when I began this work" --
or, "I had no other object

31:22.249 --> 31:25.819
when I began the following work,
than to extend and explain more

31:25.819 --> 31:27.949
fully the memoir,
which I read at the public

31:27.945 --> 31:30.455
meeting of the Academy of
Science in the month of April,

31:30.460 --> 31:33.840
1787" (remember when
radical was introduced and so

31:33.838 --> 31:37.408
on) "on the necessity of
reforming and completing the

31:37.405 --> 31:39.655
nomenclature of Chemistry."

31:39.660 --> 31:43.800
So that's all he was trying to
do was get a proper nomenclature

31:43.804 --> 31:46.744
that would be useful,
in contrast to all this

31:46.744 --> 31:48.354
alchemical nonsense.

31:48.349 --> 31:48.879
Okay?

31:48.880 --> 31:50.640
"While engaged in this
employment,

31:50.640 --> 31:53.090
I perceived,
better than I had ever done

31:53.090 --> 31:55.280
before,
the justice of the following

31:58.357 --> 32:00.367
Logic and some other
works."

32:00.369 --> 32:02.229
So this is what Condillac said.

32:02.230 --> 32:04.710
"We think,
only through the medium of

32:04.705 --> 32:05.185
words.

32:05.190 --> 32:08.380
Languages are true analytical
methods.

32:08.380 --> 32:12.090
Algebra, which is adapted to
its purpose in every species of

32:12.088 --> 32:13.898
expression,
in the most simple,

32:13.903 --> 32:15.823
most exact, and best manner
possible,

32:15.818 --> 32:20.378
is at the same time a language
and an analytical method.

32:20.380 --> 32:25.280
The art of reasoning is nothing
more than language,

32:25.275 --> 32:27.425
well arranged."

32:27.430 --> 32:31.380
So Lavoisier goes on to say:
"Thus, while I thought

32:31.382 --> 32:34.582
myself employed only in forming
a Nomenclature,

32:34.578 --> 32:37.568
and while I proposed to myself
nothing more than to improve the

32:37.567 --> 32:41.297
chemical language,
my work transformed itself by

32:41.300 --> 32:43.410
degrees,
without my being able to

32:43.413 --> 32:45.723
prevent it,
into a treatise upon the

32:45.715 --> 32:47.725
Elements of Chemistry."

32:47.730 --> 32:51.020
So in the process of reforming
the language,

32:51.021 --> 32:55.081
he reformed the whole
understanding of the science.

32:55.078 --> 32:58.478
"The impossibility of
separating nomenclature of a

32:58.477 --> 33:02.007
science from the science itself,
is owing to this,

33:02.008 --> 33:06.538
that every branch of physical
science must consist of three

33:06.538 --> 33:09.198
things;
the series of facts

33:09.195 --> 33:11.935
which are the object of the
science,

33:11.940 --> 33:15.570
the ideas which
represent these facts,

33:15.568 --> 33:20.028
and the words by which
the ideas are expressed.

33:20.028 --> 33:24.558
Like three impressions of the
same seal, the word ought to

33:24.557 --> 33:28.367
produce the idea,
and the idea to be a picture of

33:28.369 --> 33:29.879
the fact."

33:29.880 --> 33:32.690
So all these things have to be
harmonious.

33:32.691 --> 33:33.241
Right?

33:33.240 --> 33:36.770
Three impressions of the same
seal.

33:36.769 --> 33:40.219
"And, as ideas are
preserved and communicated by

33:40.215 --> 33:43.285
means of words,
it necessarily follows that we

33:43.291 --> 33:47.121
cannot improve the language of
any science without at the same

33:47.117 --> 33:49.437
time improving the science
itself;

33:49.440 --> 33:51.540
neither can we,
on the other hand,

33:51.541 --> 33:54.601
improve a science,
without improving the language

33:54.601 --> 33:57.151
or nomenclature which belongs to
it.

33:57.150 --> 34:00.340
However certain the facts of
any science may be,

34:00.338 --> 34:04.458
however just the ideas we may
have formed of these facts,

34:04.460 --> 34:08.330
we can only communicate false
impressions to others,

34:08.329 --> 34:11.309
while we want words by which
these may be properly

34:11.309 --> 34:12.279
expressed."

34:12.282 --> 34:12.832
Right?

34:12.829 --> 34:17.649
So clarity, as opposed to
obscurity, was his goal;

34:17.650 --> 34:20.120
as opposed to Newton or the
alchemists.

34:20.119 --> 34:20.639
Right?

34:20.639 --> 34:26.089
Facts, ideas and words,
and they all have to tie into

34:26.088 --> 34:30.908
one another as impressions of
the same seal.

34:30.909 --> 34:31.659
Okay?

34:31.659 --> 34:34.309
So he presented things,
as he had advertised,

34:34.313 --> 34:36.753
in a new order;
very different from any book on

34:36.753 --> 34:38.583
chemistry that had been written
before.

34:38.579 --> 34:42.309
First was doctrine,
-- that is, the theory -- the

34:42.309 --> 34:46.429
first part of the book,
which is a two-volume book.

34:46.429 --> 34:50.019
So almost all of the first --
no, about two-thirds,

34:50.019 --> 34:53.179
I think, of the first volume
are doctrine.

34:53.179 --> 34:56.519
And then nomenclature;
that's what he had set out to

34:56.518 --> 34:56.758
do.

34:56.760 --> 35:00.370
And finally operations,
how you can actually repeat

35:00.371 --> 35:03.911
this stuff for yourself,
what devices you need.

35:03.909 --> 35:07.429
Of course, he was very wealthy
and could employ people to

35:07.429 --> 35:10.069
manufacture all the equipment he
needed;

35:10.070 --> 35:12.580
not everybody could do that.

35:12.579 --> 35:16.159
But he showed exactly how it
was done and gave great -- it's

35:16.155 --> 35:18.635
easy to understand exactly what
he did.

35:18.639 --> 35:22.469
Now, one of the first things he
turned his attention to was

35:22.472 --> 35:23.202
elements.

35:23.199 --> 35:26.179
He says:
"…if by the name

35:26.175 --> 35:28.915
elements we mean to designate
the simple,

35:28.920 --> 35:32.620
indivisible molecules"
(molecule just means little

35:32.617 --> 35:35.627
thing, right?) "that make
up substances,

35:35.630 --> 35:39.330
it is probable we do not know
what they are."

35:39.329 --> 35:41.619
(They're just too small. Right?)

35:41.619 --> 35:43.449
"But if,
on the contrary,

35:43.445 --> 35:46.085
we associate with the name of
elements,

35:46.090 --> 35:50.000
or the principles of
substances, the idea of the

35:50.001 --> 35:53.831
furthest stage to which analysis
can reach,

35:53.829 --> 35:58.069
all substances that we have so
far found no means to decompose

35:58.067 --> 36:02.027
are elements for us…
they behave with respect to us

36:02.027 --> 36:04.317
like simple substances."

36:04.320 --> 36:07.970
So it's an operational,
not a philosophical,

36:07.971 --> 36:10.011
definition of element.

36:10.010 --> 36:13.340
If you can't break it apart,
consider it an element until

36:13.342 --> 36:14.832
you can break it apart.

36:14.829 --> 36:17.349
We have elements here,
the chemical elements.

36:17.349 --> 36:22.049
Are they elements,
according to Lavoisier's

36:22.045 --> 36:23.495
definition?

36:23.500 --> 36:26.310
Like here we see cerium,
praseodymium,

36:26.307 --> 36:29.417
neodymium, promethium,
samarium, europium,

36:29.420 --> 36:30.560
gadolinium.

36:30.559 --> 36:33.329
Are they elements,
according to Lavoisier?

36:33.329 --> 36:33.989
Students:  No.

36:33.989 --> 36:34.749
Prof: Why not?

36:34.750 --> 36:35.520
Students:
You can break them.

36:35.518 --> 36:38.328
Prof: You can break them
apart, into nuclei and

36:38.333 --> 36:38.973
electrons.

36:38.969 --> 36:41.939
The nuclei you can break apart
into protons and neutrons,

36:41.936 --> 36:45.166
and you can break these things
apart into quarks and so on.

36:45.170 --> 36:47.180
But, for Lavoisier,
or for chemists,

36:47.181 --> 36:49.891
those are elements,
because you don't break them

36:49.885 --> 36:50.455
apart.

36:50.460 --> 36:52.320
Okay?

36:52.320 --> 36:54.990
So here's a table of simple
substances,

36:54.989 --> 36:56.889
in the first English
translation of the

36:59.090 --> 36:59.840
Chimie.

36:59.840 --> 37:01.830
So here's a table of the
elements: "Simple

37:01.827 --> 37:04.157
substances belonging to all the
kingdoms of nature,

37:04.159 --> 37:07.019
which may be considered as the
elements of bodies."

37:07.018 --> 37:10.398
So what are the first two
elements, things that you can't

37:10.396 --> 37:11.236
break apart?

37:11.239 --> 37:13.519
Student:  Light.

37:13.518 --> 37:17.158
Prof: Light and heat are
the first two elements -- which

37:17.163 --> 37:19.693
we don't see in Mendeleev's
table, right?

37:19.690 --> 37:22.460
Because they're fundamentally
different from the other

37:22.460 --> 37:24.920
elements, because they don't
have any weight.

37:24.920 --> 37:28.850
You can weigh a gas but you
can't weigh light,

37:28.851 --> 37:31.211
and you can't weigh heat.

37:31.210 --> 37:31.950
Okay?

37:31.949 --> 37:36.429
So he gives new names to these
things -- light and caloric --

37:36.429 --> 37:38.519
and what the old name was.

37:38.518 --> 37:41.548
Light used to be called light
too, but in his new system he's

37:41.552 --> 37:44.082
going to keep the old name;
or "caloric",

37:44.079 --> 37:46.429
he's going to use for what used
to be called heat;

37:46.429 --> 37:48.549
or "the principle or
element of heat";

37:48.550 --> 37:50.980
or "fire";
or "igneous fluid";

37:50.980 --> 37:52.750
or "the matter of fire or
heat".

37:52.750 --> 37:55.380
Those were terms people had
used before, but he's going to

37:55.382 --> 37:56.862
call them "caloric".

37:56.860 --> 37:57.660
Okay?

37:57.659 --> 38:01.869
Now, if you have caloric,
you must be able to measure it.

38:01.869 --> 38:04.239
If you can't weigh it,
what you can do;

38:04.239 --> 38:06.519
you can use a
"calorimeter"

38:06.523 --> 38:07.543
to measure it.

38:07.539 --> 38:10.939
And this is the calorimeter
manufactured and used by

38:10.940 --> 38:12.740
Lavoisier;
and also Laplace,

38:12.737 --> 38:15.907
a younger man who was his
colleague, who became a great

38:15.909 --> 38:18.199
mathematician,
as you probably know.

38:18.199 --> 38:19.349
So here's the thing.

38:19.349 --> 38:20.739
It's big.

38:20.739 --> 38:23.579
That's a three-foot rule.

38:23.579 --> 38:25.579
So this thing stood this high
off the table,

38:25.577 --> 38:25.947
right?

38:25.949 --> 38:27.389
Okay?

38:27.389 --> 38:28.209
Now here's what it is.

38:28.210 --> 38:30.360
There's a lamp that's going to
make fire.

38:30.360 --> 38:33.270
There's oil in the well of the
lamp.

38:33.268 --> 38:36.778
You're going to measure how
much heat you get out of burning

38:36.775 --> 38:37.425
that oil.

38:37.429 --> 38:41.519
So you put it inside this
bucket, and you put the bucket

38:41.518 --> 38:44.418
in this mesh cage and put the
lid on.

38:44.420 --> 38:47.490
Then you put that cage,
and its lid,

38:47.485 --> 38:49.145
up into this can.

38:49.150 --> 38:50.040
Okay?

38:50.039 --> 38:54.579
And now you light the flame,
in there.

38:54.579 --> 38:55.959
You want to measure how much
heat it gives.

38:55.960 --> 38:58.500
How do you measure the heat?

38:58.500 --> 39:03.320
What you do is surround it by
melting ice.

39:03.320 --> 39:05.920
So the heat will melt the ice.

39:05.920 --> 39:07.810
Now there's going to be a
problem.

39:07.809 --> 39:10.559
Obviously the more heat,
the more ice you melt.

39:10.559 --> 39:13.319
But that's not the only place
heat's coming from.

39:13.320 --> 39:15.920
Where else will it come from,
to melt the ice?

39:15.920 --> 39:16.410
Students:  Outside.

39:16.409 --> 39:17.959
Prof: From outside.

39:17.960 --> 39:20.420
So this is where the thing is
clever.

39:20.420 --> 39:23.350
So there's another can,
outside that can,

39:23.347 --> 39:26.787
and you fill it with ice,
which is an insulator,

39:26.789 --> 39:28.179
for the inside.

39:28.179 --> 39:31.159
So no heat comes from the --
any heat that comes from the

39:31.164 --> 39:33.994
outside, melts the outside ice,
not the inside ice.

39:33.989 --> 39:36.579
Only the flame will melt the
inside ice.

39:36.579 --> 39:39.739
Okay, and notice that the lids
also are covered with ice too.

39:39.739 --> 39:43.249
So it's completely surrounded
by ice, and then by another

39:43.248 --> 39:44.188
layer of ice.

39:44.190 --> 39:47.300
So your flame burns,
burns, burns,

39:47.295 --> 39:48.045
burns.

39:48.050 --> 39:51.410
And you fill -- water comes up
as they melt in both of them.

39:51.409 --> 39:55.409
And then you put that thing
underneath and turn the tap,

39:55.405 --> 39:58.015
and see how much water was
melted;

39:58.019 --> 40:00.949
only by the flame, right?

40:00.949 --> 40:03.279
And that measures how much heat.

40:03.280 --> 40:07.000
Pretty clever, huh?

40:07.000 --> 40:11.240
Okay, so that's a fact,
is measuring how much heat

40:11.237 --> 40:12.187
there is.

40:12.190 --> 40:14.210
But analysis in general is it.

40:14.210 --> 40:18.520
This is from the Oxford English
Dictionary, which Yale has a

40:18.523 --> 40:19.843
subscription to.

40:19.840 --> 40:22.150
So you can look up words to
your heart's content.

40:22.150 --> 40:23.510
It's a lot of fun.

40:23.510 --> 40:26.390
This year is the 80th
anniversary of the Oxford

40:26.393 --> 40:27.713
English Dictionary.

40:27.710 --> 40:29.730
There was a symposium,
down the hill,

40:29.726 --> 40:32.696
sponsored by the library,
including the guy that wrote

40:32.697 --> 40:35.217
that The Professor and the
Madman.

40:35.219 --> 40:37.959
Has anyone read that book about
the Oxford English Dictionary?

40:37.960 --> 40:41.630
It's a wonderful short book,
and the madman was a Yale

40:41.628 --> 40:42.388
graduate.

40:42.389 --> 40:43.789
Really, it's an interesting
story.

40:43.789 --> 40:47.429
And the other guy was one who
read the Oxford English

40:47.425 --> 40:51.475
Dictionary, cover to cover,
20 volumes, within one year.

40:51.480 --> 40:53.740
He wrote a book about that,
during the last year.

40:53.739 --> 40:54.509
It was a fun thing.

40:54.510 --> 40:57.240
But anyhow, this is -- it's fun
to look up things in the Oxford

40:57.235 --> 40:58.155
English Dictionary.

40:58.159 --> 41:00.909
And here's analysis.

41:00.909 --> 41:05.959
So you see it comes from
ana, and I think it's

41:05.963 --> 41:10.023
lisein;
but I can get some help on that.

41:10.019 --> 41:11.309
Student:  luein.

41:11.309 --> 41:12.919
Prof: luein, okay.

41:12.920 --> 41:15.290
Anyhow, but it means "to
loose," according to the

41:15.293 --> 41:16.443
Oxford English Dictionary.

41:16.440 --> 41:19.980
So it's to loose back;
to take things apart is the

41:19.983 --> 41:20.823
sense of it.

41:20.820 --> 41:24.350
And generally it's the
resolution or breaking up of

41:24.349 --> 41:28.019
anything complex into its
various simple elements.

41:28.018 --> 41:32.768
So you can analyze a passage in
literature.

41:32.769 --> 41:34.359
Okay?

41:34.360 --> 41:38.550
It's the opposite of synthesis.

41:38.550 --> 41:40.150
Okay?

41:40.150 --> 41:45.200
"The exact determination
of the elements or components of

41:45.204 --> 41:48.474
anything complex;
specifically in chemistry,

41:48.474 --> 41:52.134
the resolution of a chemical
compound into its proximate,

41:52.128 --> 41:54.148
or ultimate,
elements."

41:54.150 --> 41:56.820
Now, proximate and ultimate,
what does that mean?

41:56.820 --> 41:59.160
You can see down in the
historical uses of it what

41:59.155 --> 42:00.915
proximate and ultimate
mean.

42:00.920 --> 42:04.550
1791, this same time -- 1789,
remember,

42:05.786 --> 42:07.576
--
said, "the quantity of

42:07.581 --> 42:10.441
charcoal,
which something yields by

42:10.443 --> 42:11.863
analysis."

42:11.860 --> 42:13.770
So you find out how much
charcoal is in it.

42:13.768 --> 42:16.948
That's the word -- we now say
carbon.

42:16.949 --> 42:18.729
So that's elemental analysis.

42:18.730 --> 42:21.690
That's ultimate analysis;
take things all apart to the

42:21.693 --> 42:24.273
chemical elements,
see how much of each one.

42:24.268 --> 42:26.718
But there's also this thing
called proximate

42:26.719 --> 42:28.849
analysis,
which you can see from this

42:28.851 --> 42:29.811
quote in 1831.

42:29.809 --> 42:32.169
"Sugar,
starch and gum are proximate

42:32.166 --> 42:34.816
principles, and these we
obtained by proximate

42:34.820 --> 42:35.940
analysis."

42:35.940 --> 42:38.630
So you can take some foodstuff
and see what percentage of

42:38.628 --> 42:41.268
protein, what percentage of
sugar, or what percentage of

42:41.268 --> 42:42.948
this, that and the other thing.

42:42.949 --> 42:46.069
So what you read on a candy
bar, or something like that,

42:46.072 --> 42:48.342
that's proximate analysis,
not elemental,

42:48.342 --> 42:49.822
not ultimate analysis.

42:49.820 --> 42:53.970
So both kinds are important in
Lavoisier's work,

42:53.974 --> 42:55.304
as we'll see.

42:55.300 --> 42:59.650
Okay, so we looked at light and
caloric.

42:59.650 --> 43:01.780
Now let's look at a few of
these elements,

43:01.782 --> 43:03.292
the ultimate elements here.

43:03.289 --> 43:09.139
He had the fact,
the theory and the word for

43:09.139 --> 43:11.179
these things.

43:11.179 --> 43:14.039
So how about Azote?

43:14.039 --> 43:17.179
Why is that word -- that's the
French name for --

43:17.179 --> 43:21.169
the French still call nitrogen
azote,

43:21.170 --> 43:25.490
and in this English translation
it was called that in 1790 or

43:25.487 --> 43:25.917
'91.

43:25.920 --> 43:30.070
Okay, where does that word come
from?

43:30.070 --> 43:34.270
What does the prefix a
mean?

43:34.269 --> 43:37.039
Student:  Without.

43:37.039 --> 43:38.049
Prof: Without.

43:38.050 --> 43:39.720
And how about zo?

43:39.719 --> 43:42.419
It's great we have somebody
taking Greek.

43:42.420 --> 43:43.190
Student:  Life.

43:43.190 --> 43:45.100
Prof: Without life.

43:45.099 --> 43:48.909
In what sense is that an
appropriate name,

43:48.911 --> 43:51.981
a meaningful name for nitrogen?

43:51.980 --> 43:53.510
Alex?

43:53.510 --> 43:54.940
Student:  I think they
performed the tests on nitrogen

43:54.943 --> 43:56.393
first and it was --
Prof: What kind of tests?

43:56.389 --> 43:57.789
Student:  They would
suffocate like a bird in

43:57.788 --> 43:58.088
nitrogen.

43:58.090 --> 44:01.490
Prof: Yes,
if you put a mouse in an

44:01.485 --> 44:04.875
atmosphere of nitrogen,
it's azote.

44:04.880 --> 44:05.710
Right?

44:05.710 --> 44:07.610
So that's what the name meant.

44:07.610 --> 44:11.130
It used to be called
phlogisticated air,

44:11.132 --> 44:15.112
or gas, or mephitis,
or the base of mephitis.

44:15.106 --> 44:16.006
Right?

44:16.010 --> 44:20.000
Azote is the name that
Lavoisier decided to use for it.

44:20.000 --> 44:24.090
Or hydro-gen.

44:24.090 --> 44:26.560
How about it, help us out?

44:26.559 --> 44:30.349
Student:  Hdor
would've been water.

44:30.349 --> 44:31.529
Prof: Pardon me?

44:31.530 --> 44:32.410
Student:  Water.

44:32.409 --> 44:34.209
Prof: What about water?

44:34.210 --> 44:34.740
Hydro is water.

44:34.739 --> 44:37.439
What's gen?

44:37.440 --> 44:39.550
Student:  To leave water.

44:39.550 --> 44:41.450
Prof: It makes water.

44:41.454 --> 44:41.934
Right?

44:41.929 --> 44:46.439
So if you burn hydro-gen,
you generate water.

44:46.440 --> 44:47.260
Right?

44:47.260 --> 44:48.740
So hydrogen.

44:48.739 --> 44:49.759
Okay.

44:49.760 --> 44:53.820
How about oxy-gen?

44:53.820 --> 44:55.730
What does it generate?

44:55.730 --> 44:57.290
Students:  Acid.

44:57.289 --> 44:59.429
Prof: Acid, sourness.

44:59.429 --> 45:02.589
So oxygen is the element that
generates sourness,

45:02.590 --> 45:04.040
that generates acid.

45:04.039 --> 45:08.149
And that is the key element in
Lavoisier's theory,

45:08.148 --> 45:10.998
the oxygen theory of
combustion.

45:11.000 --> 45:14.100
Okay, so oxygen,
plus a base,

45:14.096 --> 45:16.526
or radical -- right?

45:16.530 --> 45:19.940
So these two terms meant the
same thing to Lavoisier,

45:19.938 --> 45:23.278
the fundamental radical,
the root of some substance,

45:23.284 --> 45:23.944
right?

45:23.940 --> 45:27.630
And you react it with oxygen
and it makes the stuff into an

45:27.634 --> 45:28.084
acid.

45:28.079 --> 45:32.949
Can you think of an example of
an element that you react with

45:32.951 --> 45:35.551
oxygen and it becomes an acid?

45:35.550 --> 45:37.880
Well let's just look in his
table.

45:37.880 --> 45:41.550
Sulfur;
you burn it and it becomes

45:41.550 --> 45:44.340
sulfuric acid,
or sulfurous acid.

45:44.344 --> 45:45.134
Right?

45:45.130 --> 45:47.450
Phosphorous generates
phosphoric acid.

45:47.449 --> 45:49.529
Carbon generates carbonic acid.

45:49.530 --> 45:53.520
Muriatic radical -- which we
don't know;

45:53.518 --> 45:56.848
they haven't discovered the
muriatic radical yet,

45:56.849 --> 46:01.149
the base of that acid -- but if
you burn it and combine it with

46:01.150 --> 46:03.510
oxygen, you get muriatic acid.

46:03.510 --> 46:06.080
Does anybody know what muriatic
acid is?

46:06.079 --> 46:06.539
Student:  Hydrochloric
acid.

46:06.539 --> 46:07.389
Prof: Hydrochloric acid.

46:07.389 --> 46:09.099
How much oxygen is in it?

46:09.099 --> 46:09.779
Student:  None.

46:09.780 --> 46:11.210
Prof: None, right?

46:11.210 --> 46:13.120
But that was the theory,
that you take a base,

46:13.115 --> 46:14.975
you react it with oxygen,
you get an acid.

46:14.980 --> 46:19.360
So there must have been a
muriatic radical.

46:19.360 --> 46:20.040
Okay?

46:20.039 --> 46:21.949
Unfortunately that part of it
was wrong.

46:21.949 --> 46:25.519
The same for fluoric radical.

46:25.519 --> 46:25.979
Okay?

46:25.980 --> 46:29.300
But then there were also
compound radicals,

46:29.302 --> 46:33.262
radicals that were only
proximate, not ultimate;

46:33.260 --> 46:37.560
radicals that had several other
elements in them.

46:37.561 --> 46:38.281
Right?

46:38.280 --> 46:41.980
And here were some of those,
a list of those radicals,

46:41.980 --> 46:45.890
with the names that Lavoisier
decided to use for them.

46:45.889 --> 46:48.539
And many of them,
all the ones indicated by an

46:48.539 --> 46:51.719
arrow, are ones that Scheele had
already discovered;

46:51.719 --> 46:54.089
like tartaric,
citric, oxalic,

46:54.094 --> 46:55.574
benzoic, lactic.

46:55.570 --> 46:58.380
Lithic acid was another one
that I didn't mention before,

46:58.376 --> 47:02.416
which comes from stones;
see, it's from urinary calculus.

47:02.420 --> 47:05.580
Okay, so those were compound
radicals.

47:05.579 --> 47:09.469
And that's the end of today's
lecture.

47:09.469 --> 47:14.999