ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 393 



alkali from the formate by the acid derived from the sugar. It is 

 suggested that, on account of this increased gas production, a medium 

 containing sodium formate (0 - 5 p.c.) and glucose (1"5 p.c.) might be 

 used as a delicate test for gas-producing strains. 



Oxidation of Thiosulphate by certain Bacteria in Pure Culture.* 

 W. T. Lockett in the course of investigations on the oxidation of thio- 

 sulphate on bacterial sewage niters, has succeeded in isolating an 

 organism which is apparently responsible for the observed chemical 

 change. This organism does not grow on ordinary laboratory media, 

 but can be cultivated on a solid gelatin medium (made without bouillon 

 and containing ammonium sulphate ■ 1 p.c. and sodium thiosulphate 

 - 4 p.c). On inoculation with active nitrates a large number of slow- 

 growing circular non-liquefying bluish-white colonies develop. The 

 oxidation of thiosulphate solution in vitro takes place very rapidly, while 

 uninoculated control solutions show no change after several months 

 incubation. Further experiments are in progress with regard to the 

 morphology and classification of the organism in question. 



* Proc. Roy. Soc, Series B, lxxxvii. (1914) pp. 441-4. 





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Aug. 19th, 1914 '2 d 



