( 160 ) 
iMilk is the well known basis of all the operations 
‘of the dairy, _Few things have more engaged the 
attention of chemists. Boyle, Boerhave, Hoffinan 
and Macquer, all the old school and many of the 
new,(1) bave employed themselves in detecting its 
constituent parts, and in establishing their several 
proportions. On the first branch of the enquiry 
they have sufficiently succeeded, and we according- 
dy know, that this very ‘important fluid is principally 
composed of an oily matter, of curd, of an essential 
salt, called sugar of milk, and ofserum. But on the 
other branch of the enquiry, so various have been 
the resuls of experiments made on the milk of dif- 
ferent animals, and of the same animal at different 
times, that it continues to be the reproach of che- 
mistry ; and we have now before us the acknowledg- 
‘ment of M. Perthuys, of the French Institute, that 
“ to determine these proportions with the necessary 
exactness is impossible.” Fortunately, howevery the 
pride of science is more affected by this failure, than 
the interests of agriculture. 
Milk, is reducible to two species ; that of rumina- 
ting animals, and. that of animals which do not ru- 
minate. Milk of the first description, abounds in 
cream and in curd; that of the other, in sugar and 
whey ; and it is on this distinction that the milk of 
cows, sheep and goats. is principally employed for 
the purposes of the dairy, while that of mares and 
asses is, with similar propriety, yielded to the ser- 
vice of medicine.(2) 
(1) Haller, Brisson, Deyeux, Parmentier and Fourcroy, &c. &c. 
(2) The medical uses of asses’ milk have come dewn to us from Hypocrates and 
