84 
PLINY'S NATUEAL HISTOEY. 
[Book XI. 
coagulate, and assume the hardness of pumice. She-asses, as 
soon 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, Poppsea,^^ the wife of Domitius 'Neio, 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 also 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 
mammee 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^"* of milk, and is of a thicker con- 
sistency than the part which is known as the serum." We 
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. 
-3 See B. xxyiii. c. 12. Poppaea Sabina, first the mistress, then the wife, 
of the Emperor Nero. 
2* " Spuma." He calls it so, because it floats on the surface. See B. 
xxviii. c. 35. The " acor," or acrid liquid, which he speaks of, is, no 
doubt, butter-milk, Or whey. 
