[1] Page 13. The opening lecture was twice postponed on account of Dr.
Faraday’s illness.
[2] Page 22. _Platinum_, with one exception, the heaviest body known,
is 21½ times heavier than water.
[3] Page 22. _Aluminium_ is 2½ times heavier than water.
[4] Pages 23 and 24. _Power or Property in Water._--This power--the
heat by which the water is kept in a _fluid_ state--is said, under
ordinary circumstances, to be _latent_ or _insensible_. When, however,
the water changes its form, and, by uniting with the lime or sulphate
of copper, becomes _solid_, the heat which retained it in a liquid
state is evolved.
[5] Page 23. _Anhydrous Sulphate of Copper_: sulphate of copper
deprived of its water of crystallisation. To obtain it, the blue
sulphate is calcined in an earthen crucible.
[6] Page 29. _Add a little liquid to the marble, and decompose
it._--Marble is composed of _carbonic acid_ and _lime_, and, in
chemical language, is called _carbonate of lime_. When sulphuric acid
is added to it, the carbonic acid is set free, and the sulphuric acid
unites with the lime to form sulphate of lime.
_Carbonic acid_, under ordinary circumstances, is a colourless
invisible gas, about half as heavy again as air. Dr. Faraday first
shewed that, under great pressure, it could be obtained in a liquid
state. Thilorier, a French chemist, afterwards found that it could be
solidified.