290 EXPERIMENT STATION RECORD. 



for which heating for 20 minutes at 60° has been found by T. Smith and 5 minutes 

 at 65° by Bang and Stribolt sufficient when proper precautions are observed. The 

 home pasteurization of milk for infant feeding is recommended. 



Experimental investigations on the sterilization of milk with hydrogen 

 peroxid, with special reference to the method of Budde, M. Lukin (Centbl. 

 Ball, [etc.], 2. AM., 15 {1905), Nos. 1, pp. 20-32; 4-6, pp. 165-174).— -The literature 

 of hydrogen peroxid as a milk preservative is reviewed, and extended experiments 

 are reported, from the results of which the author draws in substance the following 

 conclusions: 



Milk can be sterilized by the addition of hydrogen peroxid. In neutral or in 

 weakly alkaline solutions the bactericidal action of hydrogen peroxid is much greater 

 than in acid solutions. Commercial hydrogen peroxid always contains hydrochloric 

 acid, and for that reason such preparations should be neutralized, preferably just 

 before using. 



The temperature exerts a great influence on the bactericidal action of hydrogen 

 peroxid, the lower the temperature the weaker the action. Quantitative investiga- 

 tions have shown that for the sterilization of milk at room temperature a much 

 greater quantity of hydrogen peroxid is required than at incubator temperature. 

 The author's experiments have shown that the temperature of 52° C. recommended 

 by Budde is still more favorable, the quantity required for sterilization being at this 

 temperature reduced to a minimum. 



The number of bacteria in the milk is of importance in sterilization by hydrogen 

 peroxid. At room and incubator temperatures the quantity required increases with 

 the bacterial content. At 52° this relation is no longer so noticeable. 



For the sterilization of milk at the lower temperatures a relatively large quantity 

 of hydrogen peroxid is required — in the author's experiments 0.07 to 1.5 per cent, 

 corresponding to 24.5 to 600 cc. of the 3 per cent solution per liter. This method is 

 not practical, as the milk so treated is too greatly diluted and can not be consumed 

 on account of its disagreeable taste. 



The Budde method — addition of hydrogen peroxid with simultaneous heating of 

 the milk to 52° — is practical for both fresh and market milk. The author's results 

 confirm those of Budde that 0.036 per cent or 12 cc. of the 3 per cent solution per 

 liter is sufficient, except when the bacterial content is very high, when 0.05 per cent 

 is required. Hay and coli bacilli and streptococci added to milk in large numbers 

 are completely destroyed by treatment with 0.036 per cent at 52°. 



Milk treated by the Budde method contains small quantities of hydrogen peroxid, 

 which is recognizable by taste. The complete removal of the hydrogen peroxid 

 from the milk is desirable from both hygienic and practical standpoints. The 

 author's experiments with blood serum, fibrin, meat, and egg albumin along this 

 line have not given satisfactory results. 



The author also presents in conclusion a summary of the principal advantages and 

 disadvantages of the Budde method. 



Investigations on the preservation of milk with formalin, H. de Rothschild 

 and L. Netter {Rev. Hyg. et Med. Infant., 4 {1905), No. 4, pp. 334-352) .—The authors 

 review the literature of this subject and present the results of experiments with dogs 

 having gastric fistulas. In the proportion of 1:10,000, as recommended by von 

 Behring, formalin is not believed to destroy pathogenic bacteria or prevent the devel- 

 opment of all saprophytic species, while it lessens the digestibility of the casein. 



In the experiments here reported the digestion of milk treated with formalin in 

 the proportion of 1:2,000 was slower and less complete than that of ordinary milk, 

 while in the proportion of 1:5,000 no differences were appreciable. One of the ani- 

 mals consumed daily for 6 weeks about 500 cc. of milk preserved with formalin in 

 the proportion of 1:2,000 and gained considerable in weight. It is believed to be 



