FROM FARM TO CONSUMER 291 



occasionally used, does not appear to have any very serious 

 action upon animal tissues or upon nutrition. As soon as 

 somewhat larger quantities are used, the formaldehyde 

 renders the casern of the milk more or less indigestible, 

 retards the coagulation of milk by rennin, and interferes 

 with gastric digestion. The practice of adding formalde- 

 hyde to milk is entirely indefensible and should never be 

 countenanced under any circumstances. 



Solutions of boric acid were once sold to the dairymen 

 under the name of " Aseptine," and at one time were com- 

 monly used as preservatives for milk. Salicylic acid and 

 benzoic acid are rarely used. 



The object of adding bicarbonate of soda is not so much 

 to preserve milk as to neutralize its acidity and thus retard 

 coagulation and disguise the taste of souring milk. 



An ingenious method of preserving milk was advocated 

 by Budde, who recommended the use of a three per cent 

 solution of peroxide of hydrogen and an exposure to a 

 temperature of 52 C. Peroxide of hydrogen is an active 

 germicide, and the addition of the heat almost sterilizes the 

 milk so treated. Attempts have also been made to remove 

 the traces of hydrogen peroxide remaining in the milk after 

 such treatment. However, these attempts have not proven 

 practicable, and the milk still contains small amounts of the 

 unchanged hydrogen peroxide. The amounts of this chemi- 

 cal proposed by Budde have little or no practical germicidal 

 action, and if employed in sufficient quantities it imparts a 

 taste to the milk and renders it unfit for human consump- 

 tion. It is not that hydrogen peroxide in small quantities, 

 and when pure, is particularly harmful, but the addition of 

 any chemical preservative to milk must be combated upon 

 general principles. 



A simple test to determine whether an antiseptic or 

 chemical preservative has been added to the milk is known 

 as the "souring test." That is, a portion of the sample is 

 placed in a flask and allowed to stand overnight at room 



