AGEICTJLTURAL CHEMISTRY — AGROTECHNY. 315 



nitric, sulphuric, and pliosphoric acids. Amyl alcotiol may be substituted for 

 tlae ettier. 



Estimating' the bacterial content of milk, with particular reference to 

 the catalase test, W. Kuntze (CentW. Bakt. [etc.], 2. AM., SO (1911), No. IS, 

 pp. 1-53). — When working with Koning's fermentation apparatus the results 

 were not always satisfactory. The author, therefore, constructed a series of 

 tubes on the plan of Lunge's nitrometer, and with which it was possible to work 

 several samples of milk at the same time. 



He distinguishes between 2 types of catalase, viz, primary catalase, which 

 originates from the mammary gland (under normal and abnormal conditions), 

 and secondary catalase, which is exotic. A milk which has a low catalase and 

 acid figure at the outset and a low catalase figure after incubating for 2 hours 

 is considered fresh. Catalase he considers not directly dependent upon the fat 

 content of the milk, as the catalase content was not always the highest in the 

 end milks. Koning's contention that milks obtained earlier than from 3 to 4 

 weeks after parturition should not be fed to infants is not supported by the 

 author, who believes that 14 days is a sufficient length of time. He illustrates 

 this by practical examples. 



Determining the bacterial content of milk by the usual methods is not deemed 

 an adequate criterion. The fermentation tests did not always yield entirely 

 satisfactory results, and the author ascribes the favorable results obtained by 

 the rennet test with milk having a low bacterial content to the fact that such 

 samples usually come from healthy animals, the normal digestion processes in 

 which have a favorable influence upon the bacterial flora of the milk. When 

 the animals were given green feed during the summer months the rennet test 

 was the least positive. The relation between Bacillus aerogenes, B. coli, and 

 the true lactic-acid bacteria was found to vary very much during the summer 

 and winter months, so that there can not be expected a low finding in winter 

 with the fermentation test and a high one in summer. This would indicate 

 that the racial characteristics of certain coli bacilli on green feed were respon- 

 sible for their lesser occurrence in the test during the summer months. 



SchaefEer's curd tester, Geimmee (MUchw. ZentU., 7 (1911), No. 5, pp. 211- 

 2i3).— This method, which has been described in detail (E. S. R., 22, p. 212), 

 was not found to be entirely satisfactory. Preference is therefore given to the 

 usual ammonium sulphocyanate method for iron, which yielded more reliable 

 results. For detecting iron in curd the method is as follows : A small amount 

 of curd is mixed with from 2 to 3 cc. of water, and then 1 cc. of hydrochloric 

 acid, and a few crystals of ammonium sulphocyanate are added. In the pres- 

 ence of iron a definite red coloration is produced. 



Report in reg'ard to the progress made in dairy chemistry and dairying 

 during the second half of 1910, Grimmer (MUchw. Zenthl., 7 (1911), No. 2, 

 pp. -'i9-70). — Continuing previous summaries (E. S. R., 24, p. 612), the topics 

 considered are the various kinds of milk, milk constituents, changes in milk and 

 milk constituents, bacteria, enzyms, and antibodies, milk as a food, dairy prod- 

 ucts, dairy apparatus, methods for examining milk, and keeping of animals and 

 milk products. 



Report in regard to the progress made in dairy chemistry and dairying 

 during the first half of 1911, Grimmer (MUchw. ZentU., 7 (1911), No. 8, pp. 

 337-361). — Data corresponding to the above are presented for the first half of 

 1911. 



Methods for the analysis of sulphur intended for agricultural purposes 

 (Bui. Mens. Off. Renseig. Agr. [Parish, 10 (1911), No. 5, pp. 546-548).— A de- 

 scription of the official French methods, with the definitions for various kinds 

 of sulphur used in agriculture. The methods are for the determination of the 



