AGRICULTURAL CHEMISTRY AGROTECHiSrY. 717 



The detection of formic acid in sirups, H. Kreis (Mitt. Lebensm. Vntersuch. 

 u. Hyg., Schu-eiz. Osndhtsamt., 3 (1912), Wo. 5, pp. 266, 267).— Natural rasp- 

 berry juice contains only infinitesimal amounts of formic acid. In order to 

 obtain correct results it is necessary to distill with steam and without the 

 addition of sulphuric acid. 



Biochemic reactions and th-e bacterial count of milk, H. C. Campbell (V. S. 

 Dept. Agr., Bur. Anim. Indus. Rpt. 1911, pp. 195-224, pi. 1, fig. 1). — In coopera- 

 tion with the Pennsylvania Live Stock Sanitary Board, comparisons were made 

 of the catalase. acid, reductase, fermentation, alcohol, and temperature tests 

 with the bacterial count. 



There seemed to be little difference in the catalytic power of the milk of 

 individual cows drawn at different intervals after milking and kept in the 

 refrigerator at 15° C. When, however, the milk was taken from the udder at 

 different times of the day. more catalase seemed to be produced in the middle 

 of the day. The alcohol test was negative in almost all cases. 



The milk from a Jersey cow in an advanced period of lactation, and suffering 

 from a severe form of gastro-enteritis, was examined for a period of 12 days. 

 " The milk from the animal reacted strongly to the alcohol test. . . . The 

 percentage of sediment and leucocytes contained in the milk by the Tromsdorff 

 method was 0.1. The number of leucocytes per field by the Stokes method was 

 93. The number of bacteria contained in the milk per cubic centimeter was 

 1,840." None of the bacteria was pathogenic. The catalase and alcohol tests 

 were found to run very uniform. The alcohol test was positive in every in- 

 stance, but the amount of oxygen evolved was not abnormal. The presence of 

 a certain amount of albumin seemed to produce a ix)sitive alcohol test. 



Chloroform (2 per cent) or formaldehyde (1:4,000), when added to milk as 

 a preservative, did not seem to affect the production of catalase. 



From some tests made with extracts of the mammary gland tissues, it is 

 noted that by passing the extract through a Pasteur porcelain filter the catalase 

 was removed. If, however, the extract is passed through a filter paper, the 

 filtrate is found to contain a large amount of catalase, as shown by Grimmer 

 (E. S. R., 21. p. 574). 



The influence of certain bacteria on catalase production was studied. " The 

 Bacillus prodigiosus, B. sutttUis, B. proteus, and B. coli were all found to 

 increase greatly the production of catalase. Contrary to some investigators, 

 we found the B. acidi lactiei to produce a small amount of catalase, and the 

 streptococcus used in these experiments also produced only a small amount of 

 catalase. Further investigations will be necessary to enable us to state just 

 what types of streptococci are producers of catalase." 



Colostrum was found to have a large catalytic activity. Under the condi- 

 tions of the experiment, colostrum yielded IG cc. of oxygen, cream of colostrum 

 7, skimmed colostrum 7.5, and leucocytes plus a trace of skimmed colostrum 0.5 

 cc. of gas in 45 minutes. 



The results obtained by Jensen (E. S. R., 21, p. 523) with the reductase test 

 were confirmed. 



The Swiss fermentation test was carried out by placing 40 cc. of milk in a 

 large test tube and incubating at 37° for 48 hours. The character of the curd 

 was then judged according to criteria presented. 



One hundred samples of milk were examined for the purpose of making a com- 

 parison of the various biochemic reactions with the bacterial count. "Of 

 the 100 samples examined, 38 gave a catalase reading of 4 cc. or more of gas. 

 The average number of bacteria contained in these 38 samples was 4,067,260. 

 Of these samples 36.8 per cent gave a negative reaction to the alcohol test, and 

 63.2 per cent gave a positive reaction. . . . Undoubtedly, the alcohol test ia 



