als, viz.
--Gelatine, Albumen, Fibrine, Mucus. --Of Animal Acids. --Of Animal
Colours, Prussian Blue, Carmine, and Ivory Black.

CONVERSATION XXIV.

ON THE ANIMAL ECONOMY. 297

Of the principal Animal Organs. --Of Bones, Teeth, Horns, Ligaments,
and Cartilage. --Of the Muscles, constituting the Organs of Motion.
--Of the Vascular System, for the Conveyance of Fluids. --Of the
Glands, for the Secretion of Fluids. --Of the Nerves, constituting
the Organs of Sensation. --Of the Cellular Substance which connects
the several Organs. --Of the Skin.

CONVERSATION XXV.

ON ANIMALISATION, NUTRITION, AND RESPIRATION. 314

Digestion. --Solvent Power of the Gastric Juice. --Formation of a
Chyle. --Its Assimilation, or Conversion into Blood. --Of
Respiration. --Mechanical Process of Respiration. --Chemical Process
of Respiration. --Of the Circulation of the Blood. --Of the
Functions of the Arteries, the Veins, and the Heart. --Of the Lungs.
--Effects of Respiration on the Blood.

CONVERSATION XXVI.

ON ANIMAL HEAT; AND OF VARIOUS ANIMAL PRODUCTS. 336

Of the Analogy of Combustion and Respiration. --Animal Heat evolved
in the Lungs. --Animal Heat evolved in the Circulation. --Heat
produced by Fever. --Perspiration. --Heat produced by Exercise.
--Equal Temperature of Animals at all Seasons. --Power of the Animal
Body to resist the Effects of Heat. --Cold produced by Perspiration.
--Respiration of Fish and of Birds. --Effects of Respiration on
Muscular Strength. --Of several Animal Products, viz. Milk, Butter,
and Cheese; Spermaceti; Ambergris; Wax; Lac; Silk; Musk; Civet;
Castor. --Of the putrid Fermentation. --Conclusion.

CONVERSATIONS

ON

CHEMISTRY.

CONVERSATION I.

ON THE GENERAL PRINCIPLES OF CHEMISTRY.

MRS. B.

As you have now acquired some elementary notions of NATURAL PHILOSOPHY,
I am going to propose to you another branch of science, to which I am
particularly anxious that you should devote a share of your attention.
This is CHEMISTRY, which is so closely connected with Natural
Philosophy, that the study of the one must be incomplete without some
knowledge of the other; for, it is obvious that we can derive but a very
imperfect idea of bodies from the study of the general laws by which
they are governed, if we remain totally ignorant of their intimate
nature.

CAROLINE.

To confess the truth, M