MODIFICATIONS OF MILK. 57 



2d, the quantity of sugar is at its maximum at the commence- 

 ment, and subsequently diminishes; and that, 3d, the butter 

 is a very variable constituent of the milk. 



The variations observed in the columns of the sugar and of 

 the casein arise in all probability from those disturbances of 

 the mode of living, and of the tranquillity of the mind, which 

 produce a decided influence on the composition of the milk, 

 and over which the experimentalist can exert no control. 



Milk changed by disease. 



There are certain morbid states of the system which produce 

 such an influence on the milk that the infant cannot partake 

 of it without detriment to its health. It is a well-known fact 

 that the milk of women who are exposed to violent mental agi- 

 tation, to passion, grief, &c. will occasionally produce very serious 

 effects (and sometimes even instantaneous death,) on the in- 

 fant : and some physiologists and physicians are of opinion that 

 chronic diseases may be transmitted by the milk from the 

 mother to the child. 



When we read the statements of trustworthy authors re- 

 garding the instantaneously fatal effect produced by the milk 

 on the infant, on the occurrence of a sudden shock affecting 

 the mind of the mother, we cannot deny that some chemical 

 change is produced through the nervous influence on the milk, 

 although we cannot determine the nature of that change. In 

 many cases the milk, possibly, acts only as a conducting fluid, and 

 thus conveys the nervous shock from the mother to the child. 



Certain morbid changes in the milk which are dependent on 

 the formation of mammary abscess, may be easily recognised by 

 the microscope, which will then reveal the presence of pus- or 

 mucus-corpuscles. Thus in cow's milk which was drawn from 

 a teat affected with vaccinia, I found a considerable quantity 

 of mucus- or pus-corpuscles, while in the milk drawn from an- 

 other teat of the same udder there were none. 



When a mammary abscess opens internally, the milk always 

 contains pus -corpuscles, and frequently also blood-corpuscles, 

 if blood has escaped with the pus. Donne 1 has frequently made 



1 Du Lait, etc. p. 40. 



