Why should not the butter be equally acidified by oxygenation?
MRS. B.
Animal oil is not so easily acidified as the other ingredients of milk. Butter, therefore, though usually made of sour cream, is not sour itself, because the oily part of the cream had not been acidified. Butter, however, is susceptible of becoming acid by an excess of oxygen; it is then said to be rancid, and produces the sebacic acid, the same as that which is obtained from fat.
EMILY.
If that be the case, might not rancid butter be sweetened by mixing with it some substance that would take the acid from it?
MRS. B.
This idea has been suggested by Sir H. Davy, who supposes, that if rancid butter were well washed in an alkaline solution, the alkali would separate the acid from the butter.
CAROLINE.
You said just now that creamed milk consisted of curd and whey. Pray how are these separated?
MRS. B.