232 GENERATION. 



separate such parts from the blood as constitute a new or saccharine 

 combination. 



The milk, being sweet and producing sugar, would seem to show that 

 it went through the saccharine fermentation, and that its becoming sour 

 is owing to this sugar. 



Milk, while in the breast of animals, either separates into its cream 

 and milk, or else it is very thick when secreted ; for in cows, &c, when 

 it has been long retained in the udder, the lowermost, or that which 

 comes first, is the thinnest, and the very last of all is very thick and 

 almost cream. Now this is most likely from [the milk's] standing; 

 because, if a cow is almost continually milked, the milk is very thin. 



Whatever is secreted from the breast during the time of gestation is 

 generally called ' milk ;' but it differs in almost all its peculiar proper- 

 ties from that fluid. Eirst, it is not white, but of a greenish or yellow 

 colour, often a mixture of both, has no sugar, is strongly impregnated 

 with the neutral salts, does not coagulate with rennet or acids, but coagu- 

 lates with heat like serum, and is much thicker in consistence. From 

 this it would appear that when the vessels hi the breast are preparing 

 themselves for the secretion of milk, they are in some degree in a state 

 of inflammation, or something similar to it ; first, as it were filtering 

 off the parts of the blood with but little alteration, as in the first forma- 

 tion of pus ; but as this inflammation goes off, they are preparing for the 

 true secretion, as in abscess, <fcc. However, it cannot entirely be a 

 straining off of the serum, because there are much more of the salts in this 

 fluid at this time than the serum of the blood contains at that time; there- 

 fore there is a peculiar power in the vessels of the part to separate these 

 salts, as must be the case in the lacrymal gland of the eye. 



Milk, when collected in the breast, &c, and not drawn off, but a cer- 

 tain quantity constantly confined, so as in some measure to distend the 

 ducts, gives the stimulus of a non-secretion, or may be said to act as a 

 sedative ; but if the breast be emptied, and kept almost constantly so, 

 which is generally the case when the mother gives suck, then the 

 emptiness of the ducts gives the stimulus for secretion ; and the more it 

 is kept so, the more it secretes. 



The secreting vessels of the milk are very much affected by the dispo- 

 sition of the animal for venery. I had a cow that often took the bull 

 without breeding. Every time she was a bulling her milk was bad, 

 and but little of it. This is observed by all cow-keepers ; but the reason 

 they give for the small quantity Is " that she will not give down her 

 milk." 



Cream is an oil chemically combined with an animal substance, which 

 is specifically lighter than milk. It is composed of round bodies swimming 



