MILK GLOBULE. 211 



I shall speak of all globules less than this figure as 

 granules, and all above as globules. Every sample 

 of milk I have yet examined has shown these gran- 

 ules, 1 yet in some milks much more abundant than 

 in others. In the skim- milk the granule has always 

 been readily found, even in those milks where it was 

 nearly absent in the cream. These globules being 

 composed of various fats, surrounded by a peUicle, 

 are intimately mixed with the milk as it comes from 

 the cow ; but their position soon becomes changed as 

 they come under the influence of gravity, and they 

 rise to the surface of the milk to form cream. As 

 the weight to the covering of the fat globules, which 

 is heavier than water, increases proportionately to 

 the volume of fat as the sphere is diminished in 

 diameter, the various globules show difference in 

 physical action. When the weight of the ^covering 

 is just or nearly sufficient to balance the low specific 

 gravity of the fats, the globules remain nearly sta- 

 tionary in the fluid ; when, however, the globule is 

 large, the specific gravity of the mass is so much 

 less than that of the fluid in which it occurs that it 

 speedily reaches the surface. It therefore follows 

 that the upper layer of the cream is composed of 

 larger globules than the lower layer; or, giving 

 expression to a general fact, the further you go from 

 the surface of milk which has been at rest, the 

 smaller the milk globule. 



1 That ray conclusions may not seem to have been derived without study, I 

 wish to say h.-re that January 21, 1873, 1 found recorded in my note-book consid- 

 erations involving the recognition of 9tj23 milk globules; and since that date 

 many additional observations have been made. E. L. S., October 15, 1874. 



