[PART III.]
Of OPERATIONS on ANIMAL SUBSTANCES.
[CHAP. I.]
Of Milk.
PROCESS I.
Milk separated into Butter, Curd, and Whey; instanced in Cow's Milk.
Put new Cow's milk into a flat earthen pan, and set it in a temperate heat. In ten or twelve hours time there will gather on its surface a thick matter, of a somewhat yellowish white: this is called Cream. Gently skim off this Cream with a spoon, letting the milk you take up with it run off. Put all this Cream into another vessel, and keep it. The milk thus skimmed will not be quite so thick as before: nor will it be of such a dead white, but have a little blueish cast. If all the Cream be not separated from it, more will gather on its surface after some time, which must be taken off as the former. In two or three days the skimmed milk will coagulate into a soft mass called Curd, and then it tastes and smells sour.
Cut this Curd across in several places. It will immediately discharge a large quantity of Serum. Put the whole into a clean linen cloth; hang it up, and underneath it set a vessel to receive the Serum as it drops. When the aqueous part hath done dripping, there will remain in the filter a white substance somewhat harder than the curdled milk. This substance is called Cheese, and the Serum separated from it is known by the name of Whey.