MILK. 159 



curred, such an appearance is, in all probability, due to the 

 adhesion together and partial fusion of two or more globules. 

 (See Plate XV. fig. 4.) 



There are other observers again, as Wagner, Nasse, and 

 Quevenne, who would deny to the milk globule all organ- 

 isation, and who regard it as of a perfectly homogeneous 

 nature. 



The truth in this instance, as in so many others, would 

 appear to lie in the mean. That the milk globule is not pro- 

 vided with a distinct and separate membrane, similar to that 

 of the mucous corpuscle, is proved by the impossibility of 

 demonstrating the existence of any such structure, as well as 

 by the absence of a double line around its margin, the non- 

 effect of iodine, and the coalition of the globules resulting 

 from pressure, first observed by Dujardin. 



That it is not constituted of a single perfectly homogeneous 

 substance is also demonstrated by the observations of Mandl 

 and Henle, and especially by those of the latter observer on 

 the effects produced by acetic acid. 



That the milk globule is not wholly composed of fatty 

 matter is shown by its insolubility in boiling water raised to 

 a very high temperature, in boiling alcohol, in the alkalies, 

 and by the effects of the application of acetic acid. Ether 

 dissolves the milk globules : their solution, however, it does 

 not entirely accomplish on its first application, although the 

 ether, the moment it comes in contact with the globules, 

 causes them to lose their rotundity, to fall down, and to run 

 together into masses of various sizes, but most of which still 

 present a circular outline. 



If a drop of milk be examined microscopically, after its 

 treatment by ether, a hasty observer might conclude, from 

 noticing so many of the circular masses alluded to, that the 

 re-agent had not exerted any influence on the milk globules, 

 and that these masses were the unaltered globules. This 

 view, however, a little reflection would soon show to be in- 

 correct ; for many of the circular bodies now noticed on the 

 field of the microscope are larger than even the largest milk 



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