212 CHYMISTRY APPLIED TO AGRICULTURE. 



becomes covered with a coat of cream, but it is often the 

 ease, that the most prolonged churning cannot produce any 

 butter from it. Repeated experiments have proved, that the 

 caseous matter in this kind of milk increases with the lapse 

 of time from the lying in ; and that this is so feebly dissolved, 

 as to become separated into very finely divided molecules* at 

 a temperature of 68° Fahrenheit : this substance has always 

 some viscosity, and is never dry and quivering like that of 

 cows' milk. 



The astonishing differences which appear in woman's 

 milk may be attributed to the passions of the mind, to ner- 

 vous agitation, and to frequent changes of diet. The action 

 of the two first agents is of the most powerful kind, and as 

 they are exercised most vigorously and frequently upon the 

 human species, it is not astonishing that they should exert a 

 decided influence upon the milk of women. These observa- 

 tions deserve great attention from all who are interested in 

 nursing children. 



The milk of the ass bears a strong resemblance to that of 

 woman; it throws up a cream which is neither thick nor 

 abundant, and from which there may be extracted, though 

 not without difficulty, a small quantity of soft, insipid, white 

 butter, which easily becomes rancid. 



Neither woman's nor asses' milk affords so much caseous 

 matter as that of the cow or sheep ; what is obtained is more 

 viscous, and possesses but a slight degree of adherence to 

 the scrum. The resemblance of asses' milk to that of wo- 

 man has caused it to be used in those cases, where it was 

 necessary to employ a mild diet. It possesses the advantage 

 over the last, of not varying so much in its quality and con- 

 sequently in its effects. 



The fluidity of mare's milk is less than of the two last- 

 mentioned kinds, and its taste is less sweet ; it furnishes 

 some cream, but it is difficult to procure butter from it ; it 

 contains but little caseous matter, and in all its products 

 bears a resemblance to the milk of the human female and 

 of the ass. 



From the foregoing statement we perceive that the ru- 

 minating animals afford similar kinds of milk, and that 

 this milk possesses peculiar and distinguishing charac- 

 teristics : all the kinds contain the same principles, but 

 these principles vary in proportion, quantity, consistency, 

 and taste. 



The difference existing amongst the several kinds of 



