MILK. 171 



It will be seen from the above analyses that the milk of 

 woman is the richest in butter, while that of the ass contains 

 the smallest amount of that element. 



The assertion made by Donne, that the quantity of butter 

 in the milk of the same species stands in relation with that 

 of the other essential ingredients of the milk, although sup- 

 ported by the researches of Peyen and Peligot is contradicted 

 by those of F. Simon. According to the analyses of Simon, 

 the quantity of sugar is greatest immediately after delivery, 

 a few days being passed this diminishes, and the amount of 

 caseine, which was at first very small, undergoes a gradual 

 augmentation. The butter Simon considers to be the most 

 variable element of the milk, its variations not being reducible 

 to any law. 



The relative proportion of the different ingredients of the 

 milk of animals may be modified, and almost altered, at will, 

 by the adoption of a certain regimen. 



GOOD MILK. 



The purity and the richness of milk were formerly estimated 

 by its specific gravity, which is about 1-032 ; if the milk was 

 poor in cream, or if it was diluted with water, it was sup- 

 posed that the gravity of the fluid would be in the first case 

 increased, and in the second lessened. 



The cream being the lightest element of the milk, its 

 deficiency or its abtraction would, of course, increase the 

 density of the remaining fluid, and the addition of water, 

 after the removal of the cream, which is also of less weight 

 than milk which is even pure and rich, would, of course, 

 raise the gravity of the milk either up to or even beyond its 

 natural weight. 



Now, the abtraction of the globular element of the milk 

 and the addition of water are the two frauds most frequently 

 had recourse to ; and they are of such a nature as to elude 

 detection by reference to the specific gravity of the milk, 

 when they are both put in practice in combination. 



