The lactic acid, from the whey of milk.
The sebacic, from oil or fat.
Those produced during the decomposition of animal substances by heat, are the prussic and zoonic acids. This last is produced by the roasting of meat, and gives it a brisk flavour.
CAROLINE.
The class of animal acids is not very extensive?
MRS. B.
No; nor are they, generally speaking, of great importance. The prussic acid is, I think, the only one sufficiently interesting to require any further comment. It can be formed by any artificial process, without the presence of any animal matter; and it may likewise be obtained from a variety of vegetables, particularly those of the narcotic kind, such as poppies, laurel, &c. But it is commonly obtained from blood, by strongly heating that substance with caustic potash; the alkali attracts the acid from the blood, and forms with it a prussiat of potash. From this state of combination the prussic acid can be obtained pure by means of other substances which have the power of separating it from the alkali.
EMILY.
But if this acid does not exist ready formed in blood, how can the alkali attract it from it?
MRS. B.