526 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Nitrite- formation by various Bacteria.* -E. I'elz has investigated 

 the amounl of nitrites which is formed by various organisms, particularly 

 intestinal organisms, in the presence of nitrates. This research was 

 suggested by Emmerich's theory that the toxic symptoms of cholera are 

 due to extensive formation of nitrites in the intestinal canal. The author 

 has used the method of Griess, finding it more satisfactory than other 

 complicated gravimetric methods. According to the amount of nitrite 

 produced, the organisms investigated were assigned to three groups. 

 Very small quantities were produced by Shiga's bacillus and the strepto- 

 coccus. In the intermediate class are placed typhoid, paratyphoid A, 

 B. coli, and some allied organisms. The class of good nitrite-forms com- 

 prises all the vibrios, Flexner's dysentery bacillus, and paratyphoid B. 

 Vibrio cholera? does not stand out from the rest of this group, either in 

 respect of the total quantity of nitrites produced or of the rate at which 

 they are formed. 



Action of Bacillus Lactis Aerogenes upon Glucose. f — G. S. Walpole 

 has investigated the ''crude glycol" formed by tins action, and finds 

 that it is largely composed of two optically inactive 2 : 3 butanediols. 

 Small quantities of the phenylarethanes of other glycols were also ob- 

 tained. In the presence of oxygen, acetylmethylcarbinol is also produced 

 from 2 : 3 butanediol by this organism. Fructose is decomposed in a 

 similar manner. 



Variations of Typhoid and Dysentery Bacilli.:}: — Reiner Midler 

 discusses the mutations exhibited by these organisms when grown upon 

 media containing isodulcite. Under these conditions, the growth shows 

 the formation of papilla? and of daughter-colonies. The phenomenon is 

 very constant, and may be produced when only a small trace of the sugar 

 is present. Isodulcite is structurally a methyl-pentose, but the author 

 has been unable to obtain the other methyl-pentoses. fukose and rhodeose, 

 for investigation. This mutation, which appears to possess a diagnostic 

 value, is explained by the author upon the side-chain theory. Mutations 

 have also been observed in old cultures of typhoid upon gelatin. 



Cultivation of Leprosy Bacillus. § — E. Bertarelli gives a review of 

 recent advances in the knowledge of this organism. Two problems 

 have of late years been solved. The organism has been successfully 

 cultivated. The disease has been communicated to animals. The cul- 

 tivation of the leprosy bacillus has occupied the attention of many, whose 

 names are recorded in this paper. The first undoubted culture of the 

 bacillus was obtained in 1905 by E. Weil, who made use of a medium 

 containing yolk of egg. Cley, more recently, has obtained cultures by 

 growing the organism upon agar in symbiosis with amcebas. The most 

 important work upon this subject has been done by Kedrowski, who 

 succeeded in cultivating the bacillus upon ordinary media, and in trans- 

 mitting the disease to rabbits bv means of cultures so obtained. This 



* Centralbl. Bakt., lte Abt. Orig., lvii. (1910) pp. 1-16. 



t Proc. Roy. Soc, Series B, lxxxiii. (1911) pp. 272-86. 



X Centralbl. Bakt., lie Abt. Orig., lviii. (1911) pp. 97-106. 



§ Centralbl. Bakt., lte Abt. Ret., xlix. (1911) pp. 65-73. 



