ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 103 



MILK PRESERVATIVES. 



BY PROF. J. B. WEEMS, AMES, IOWA. 



Mr. Chairman, Ladies and Gentlemen: 



The subject of milk preservatives is an important one to 

 those engaged in the production of dairy products. Questions 

 relating to this subject are asked by almost everyone, and I will 

 endeavor to present the subject so that it may be of interest to 

 those who are connected with the dairy industry. We find upon 

 the market many brands of preservatives, which are sold for the 

 purpose of preserving milk, butter and cheese; and we may 

 divide them into two classes: ist, those for preserving dairy 

 products intended for food, and 2d, those for preserving com- 

 posite samples in the creamery. 



The substances that are used for preservatives are boric acid, 

 borax, salicylic acid, salt, formaldehyde, etc. These are found 

 in those preservatives intended for use in foods. The substances 

 largely used for the composite samples are corrosive sublimate, 

 formaldehyde, and potassium dichromate. 



Boric acid has been used as a preservative for many years, 

 largely for milk and butter. Many of the preservatives sold in 

 packages under certain brands contain this substance. Borax, 

 which is a sodium salt of boric acid, is also largely used. (Com- 

 mon salt is found in many of the preservatives in connection 

 with borax and boric acid. One brand which is on the market 

 contains 75 per cent of boric acid and 25 per cent of borax. 

 Another is composed of two-thirds of borax and one-third com- 

 mon salt. The first is intended for preserving milk, 

 cream and butter; and the second for butter and 

 cheese. As boric acid can be purchased for 1 5 cents per 

 pound, and borax for ten cents at any drug store, we must 

 conclude that there is quite a profit in this business when these 



