84 PLINY'S NATURAL HISTORY. [Book XI. 



coagulate, and assume the hardness of pumice. She-asses, as 

 socn as they are pregnant, have milk in their udders ; when 

 the pasturage is rich, it is fatal to their young to taste the 

 mother's milk the first two days after birth ; the kind of 

 malady by which they are attacked is known by the name 

 of " colostration." Cheese cannot be made from the milk of 

 animals which have teeth on either jaw, from the circumstance 

 that their milk does not coagulate. The thinnest milk of all 

 is that of the camel, and next to it that of the mare. The milk 

 of the she- ass is the richest of all, so much so, indeed, that it is 

 often used instead of rennet. Asses' milk is also thought to 

 be very efficacious in whitening the skin of females : at all 

 events, Popptea, 23 the wife of Domitius Nero, used always to 

 have with her five hundred asses with foal, and used to bathe 

 the whole of her body in their milk, thinking that it alsp con- 

 ferred additional suppleness on the skin. All milk thickens 

 by the action of fire, and becomes serous when exposed to cold. 

 The milk of the cow produces more cheese than that of the 

 goat : when equal in quantity, it will produce nearly twice the 

 weight. The milk of animals which have more than four 

 mammas does not produce cheese ; and that is the best which is 

 made of the milk of those that have but two. The rennet of 

 the fawn, the hare, and the kid is the most esteemed, but the 

 best of all is that of the dasypus : this last acts as a specific 

 for diarrhoea, that animal being the only one with teeth in 

 both jaws, the rennet of which has that property. It is a re- 

 markable circumstance, that the barbarous nations which sub- 

 sist on milk have been for so many ages either ignorant of the 

 merits of cheese, or else have totally disregarded it ; and yet 

 they understand how to thicken milk and form therefrom an 

 acrid kind of liquid with a pleasant flavour, as well as a rich 

 butter : this last is the foam 24 of milk, and is of a thicker con- 

 sistency than the part which is known as the " serum." 25 Aft e 

 ought not to omit that butter has certain of the properties of 

 oil, and that it is used for an ointment among all barbarous 

 nations, and among ourselves as well, for infants. 



23 See B. xxviii. c. 12. Poppeea Sabina, first the mistress, then the wife, 

 of the Emperor Nero. . 



24 " Spuma." He calls it so, because it floats on the sunace. bee B. 

 xxviii. c. 35. The " acor," or acrid liquid, which he speaks of, is, no 

 doubt, butter-milk, M Or whey. 



