Whey
"The whey of milk is the opalescent liquor from which the curd has been removed in making cheese. Although not highly nutritious, it still holds a little caseine in solution, as well as the sugar and saline matter of the milk. It is rarely used as food even by the poor, but it is given to pigs. In Switzerland, however, it is considered to have medicinal virtues, especially for the cure of chronic disorders of the abdominal organs; and the treatment which is sometimes fashionable goes by the name of cure de petit lait. There is a popular notion that the whey of milk is sudorific; and hence we have our wine whey, cream-oftartar whey, alum whey, tamarind whey, etc., when the milk has been curdled by these several substances." - Dr. Henry Letheby.