776 EXPERIMENT STATION EECORD. 



approximates the mouth of June iu the northeru hemisphere. Tlie lowuess of 

 the si^ecific gravity for tlie mouths of December, January, ;iud February is 

 ascribed to a tliisJi of jjrreeu herbage, whicli was caused by copious raius. 



The aideliyde tigure of a number of samples was found to average 18.5°, using 

 tenth-normal strontia, and 17° using tenth-normal soda, which corresponds with 

 the results of Richmond and Miller. The protein-aldehyde ratio, using strontia, 

 was 0.173. 



Analyses are also rei)Orted of a sterilized milk of German origin imiiorted 

 into Java, 5 samples of sweetened condensed milk purchased in Victoria, and 

 (i samples purchased in New South Wales. Tyrosin was detected in all except 

 2 samples of the condensed milk. 



Physiology of Bacterium lactis acidi, S. Korolev (Viesfnlk Bakt. Ayron. 

 Etantsii V. K. Ferrehi, 1911, No. 18, pj). Jii)-19). — The author repeated the ex- 

 periments of Budinov (E. S. R., 22, p. 383), and obtained similar results. 

 Physiological activity as determined by the time required for coagulation 

 diminished less rapidly than cell division. 



From the data obtaine<l the author draws the following practical conclusions: 

 Liquid cultures may safely be kept in winter for 2 to 3 weeks at temperatures 

 close to zero, though with fluctuations. In the summer, up to temi)eratures at 

 about 30° C. the virulence of the physiological activity of the organisms can 

 be guarantied only for 3 or 4 days and in no ease over a week, but at temi»era- 

 tures under 20° the cultures may be kept for a week and a half. 



The chief phases in the souring of milk, and its practical significance, 

 M. Grimm {Centhl. Bakt. [rtc], 2. AM., 82 {1911), No. 3-5, pp. 65-70).— In the 

 acidification of milk by means of pure cultures of Bacterium Metis acidi there 

 were found to be 4 phases. The first phase, in which the organisms multiply 

 rapidly, lasted 4i hours after inoculation, but there was no perceptible increase 

 in acidity. In the second period there was a verj' rapid rise in acidity, which 

 lasted approximately until the sixteenth houi-. From that time until about the 

 thirty-second hour the acidity increased but at a much lower rate than in the 

 second ])eriod. During the last period there was practically no increase in the 

 acidity, though the bacteria multiplied to some extent. 



The conclusion is drawn that for practical inoculations the pure culture 

 should not be held in the thermostat more than 16 hours if the greatest activity 

 of the organism is desired. 



The influence of the products of lactic organisms upon Bacillus typhosus, 

 Zae Northrup (Micliiffan Stn. Tech. Bill. 0, pp. .'].?, /ii/s. 2). — This study of the 

 viability of B. ti/iiliosii.'i was undertaken to determine its maximum longevity 

 in milk undergoing lactic fermentation. 



In a preliminary test measured portions of lactic acid were added to a 

 definite volume of sweet milk, but this was found to be unsatisfactory as the 

 curd produced is quite dissimilar to that produced by lactic organisms, other 

 products of lactic fermentation were absent, and a certain amount of the pure 

 lactic acid was combined with the casein, leaving only a portion of the total 

 acid free to act upon the organism. A litmus lactose agar containing calcium 

 carbonate was not satisfactory as a differentiating medium because of the 

 difficulty in counting the typhoid colonies. Differential counts of ox and sheep 

 bile agar were not entirely successful as a differentiating medium for any of 

 the lactic organisms except Bactcnuni lactis acidi (Lab.). The medium finally 

 used was a lactose broth, and the method of using is described in detail. 



It was found that from 50° acidity up to 68° the lactic acid produced by 

 several tactics was strongly inhibitive to the typhoid organism. The amount of 

 acid as produced by the different organisms had a different effect on the 

 longevity of the typhoid bacillus. It is not known whether this is produced 



