INTRODUCTION. 



Of all articles of food, none requires so much of our attention as 

 milk. While it engages the scientist on account of its relation to 

 physiology and pathology, the public are interested in milk by 

 the place it occupies as a food of so general application, and by 

 the fact that it forms an important article of commerce and a base 

 for manifold industries. Cows' milk, and of late, infants' milk-foods 

 and condensed milk, are of more special interest by the fact, that in 

 the case of an insufficient or wholly wanting supply of breast milk, 

 they are destined to form, for a considerable period of time, the 

 sole food for infants. We should, therefore, be well acquainted 

 with the quality of these articles as they reach the consumer. 



To insure a supply of healthy and unadulterated food, the gov- 

 ernments of many countries have passed laws for the punishment 

 of adulterations, and in order to detect them, have taken the ex- 

 amination of the various food substances in hand. Milk, being 

 more exposed to adulteration than many other foods, ^as of late re- 

 ceived a considerable share of this attention. 



The control which a government exerts, protects the public 

 against fraud by preventing the sale of goods of inferior value at 

 high prices ; but more important is the protection which, by gov- 

 ernment interference, is gained for the health of the consumer by 

 the absolute prevention of the sale of specifically altered, spoiled 

 and adulterated milk. The poorer and working classes, and espec- 

 ially the children, suffer most, if the milk is not of the best 

 quality. 



Chemical analysis, even if carried out according to the best ap- 

 proved methods, would not bring us nearer to a satisfactory solu- 

 tion of this question, unless exact science has thoroughly invest!- 



