BUTTER: 



ITS AI^ALYSIS AND ADULTEEATIONS. 



CHAPTEE I. 



THE COMPOSITION OF BUTTER. 



Butter consists of the fatty portion of the milk of the cow. 

 It is suspended in the milk in the form of minute oU globules, 

 which, on allowiag the secretion to remain undisturbed for 

 some hours, on account of their having a lower specific gravity 

 than the liquid in which they float, rise to the surface and 

 form a layer of cream. 



It was for some time supposed that the fat globules in 

 milk were prevented from coalescence by some kind of pro- 

 tecting membrane, presumedly albuminous, and this view 

 appeared to be borne out by the fact, that the fat globules 

 are not dissolved when the milk is agitated with ether, but 

 only after desiccation will the milk yield up its fat to solvents. 

 Eecently, however, it has been shown that if the milk's solids 

 be again taken up with water so as to re-form the milk, the 

 same indifference to the action of solvents is observed. This 

 proves that no true sac or pellicle can exist, but that the 

 globular bodies are protected from immediate contact with 

 the solvent by the presence of the surrounding medium. 



