1006 EXPERIMENT STATION RECORD. 



opinion is unfavorable to this method as a means of demonstrating the direct trans- 

 formation of food fat into milk fat. 



On the Baudouin reaction in human milk fat, Engel (Ztschr. Angew. Chem., 

 19 (1906), No. 7, pp. 283-286). — A positive Baudouin reaction was regularly obtained 

 1 to lh hours after feeding sesame oil. This period was followed by a second period, 

 in which the reaction was negative, and this by a third period, in which a positive 

 reaction was again obtained. When the feeding of sesame oil was continued for 7 

 days the reaction was positive for all three periods. 



Purity of Raleigh's milk supply, F. L. Stevens (Raleigh, N. C: Bd. Aldermen, 

 May, 1905, pp.7). — Forty samples of milk collected in Raleigh, N, C, from February 4 

 to April 29 were examined, the results showing no sample containing less than 34,000 

 bacteria per cubic centimeter. Only 9 samples contained less than 100,000 and 17 

 contained more than 1,000,000. The fat content in no instance fell below 3 per cent. 

 The relation of dirt in milk to bacterial content is illustrated by the following figures: 

 Milk containing 5.2 mg. of dirt per liter showed the presence of 3,338,775 bacteria 

 per cubic centimeter; milk containing 20.7 mg., 7,079,829 bacteria, and milk con- 

 taining 36.8 mg., 12,897,600 bacteria. 



Milk treated with hydrogen peroxid, P. Adam (Rec. Med. Vit, 83 (1906), 

 No. 5, pp. 169-173). — The author endeavored to determine whether milk free from 

 hydrogen peroxid was previously treated with this substance. Storch's reagent con- 

 sisting of paraphenylenediamin, and Schardinger's reagent consisting of methylene 

 blue and an aldehyde were tested for this purpose. 



The following conclusions were reached: Raw fresh milk not previously treated 

 with hydrogen peroxid is colored red by the addition of guaiac and hydrogen per- 

 oxid, and blue by paraphenylenediamin. The methylene blue is decolorized by the 

 presence of an aldehyde. The same milk, when spoiled, no longer gives the first tw T o 

 reactions but still decolorizes Schardinger's reagent. Raw milk containing hydro- 

 gen peroxid gives the color reaction with guaiac alone or with paraphenylenediamin 

 alone and does not change the color of Schardinger's reagent. Raw milk previously 

 treated with hydrogen peroxid but no longer containing this substance gives, upon 

 again adding hydrogen peroxid, the same reactions as pure milk with guaiac and 

 paraphenylenediamin, but unless putrefied does not decolorize methylene blue. 

 Boiled milk shows none of the preceding reactions. 



Action of formalin and hydrogen peroxid on milk, P. Bandini (Riv. Ig. e 

 Sanit. Pub. [Rome'], 16 (1906), p. 23; abs. in Biochem. Centbl, 5 (1906), No. 3, p. 

 144). — According to the author, formalin interferes with the action of rennet on 

 milk, the change produced being increased by the length of time formalin acts and 

 by the amount added. On the contrary, milk treated with hydrogen peroxid shows 

 a normal reaction with rennet. 



Neither formalin nor hydrogen peroxid exerts a marked influence on the soluble 

 ferments in milk. Formalin, even in small quantities, interferes with the proteo- 

 lytic ferments such as pepsin and pancreatin and in large quantities affects to a 

 marked extent the chemical and physical properties of the precipitated casein. 

 Hydrogen peroxid does not have this effect. The addition of formalin in the pro- 

 portion of 1:5,000 to 1:10,000 preserved milk from 6 to 12 days. The addition of 

 hydrogen peroxid in the proportion of 1:100 to 3: 100 preserved milk from 1 to 6 days. 



Methods of preserving milk, P. Vieth (Fuhling's Landw. Ztg.,55 (1906), No. 4, 

 pp. 113-120).— The author discusses the importance of preventing contamination as a 

 means of improving the keeping qualities of milk and the preservation of milk by 

 means of cold, pasteurization and sterilization, chemical preservatives, and other 

 means. 



On the preservation of milk with hydrogen peroxid, Eichholz (Milchw. 

 Zentbl, 1 (1905), No. 11, pp. 500, 501).— This is a criticism of the work of Baumann 

 previously noted (E. S. R., 17, p. 74). 



