ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 259 



B. Technique.* 

 (1) Collecting: Objects, including- Culture Processes. 



Cultivation of Tubercle Bacilli from Bacterial Mixtures.f— A. 

 Dworetzky shortly describes Spengler's formalin method for the pure 

 cultivation of tubercle bacilli from bacterial mixtures, and gives details 

 of numerous attempts made by him to obtain pure cultures of the 

 tubercle bacillus from various sources, in every instance without success. 

 After varying the strength of the formalin used, and the time of 

 exposure of the mixtures, he concludes that tubercle bacilli are destroyed 

 with as equal readiness as the other bacteria. 



New Levelling Apparatus.^ — This apparatus, devised by S. Ser- 

 kowski, consists of a thick three- or four-cornered glass or porcelain 

 plate, to which are attached three or four screw feet. After levelling, it 

 may be used for plates or dishes with fluid media ; for drying cover- 

 glass preparations, where it is necessary to have thin and even films, 

 also for the observation of fluid preparations, such as urine sediments, 

 the entire microscope being placed on the levelled plate ; a microscope, 

 covered by a bell jar, can be more thoroughly protected from dust if 

 kept on this apparatus. If one half is coloured black, and under the 

 other half is pasted a line-ruled white card, like a Wolff hugel's apparatus, 

 it will serve to count the colonies on a plate. 



Simplification of the Drigalski Medium.§ — In preparing this 

 medium, Hagemann recommends the addition of milk in the place of 

 nutrose and milk-sugar. He obtains the same good results as with the 

 Drigalski-agar, and the preparation is considerably simplified. He stores 

 the milk-agar in quantities of 200 c.cm., and adds alkali, litmus and 

 crystal-violet to the medium immediately before using it. He recom- 

 mends a 2 p.c. instead of a 3 p.c agar, since it is more readily filtered. 



Differentiation of Streptococci. || — M. H. Gordon finds that different 

 varieties of streptococci behave in different ways with regard to acid 

 production when grown in litmus broths containing saccharose, lactose, 

 raffmose, inulin, salicin, and mannite ; he considers, therefore, that 

 these substances may be of service in differentiating the varieties of 

 these organisms. 



Anaerobic Cultures with Phosphorus.^ — A. W. Sellards finds 

 phosphorus a very convenient oxygen-absorbing agent as compared with 

 alkaline pyrogallate. Neither the oxides of phosphorus formed, nor the 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes ; 

 (4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c. ; 

 (6) Miscellaneous. 



t Centralbl. Bakt., l ,e Abt. Orig., xxxvii. (1904) pp. 628-31. 



X Tom. cit.. pp. 637-40 (1 fig.). 



§ Op. cit., l te Abt. Kef., xxxv. (1905) p. 794. 



|| Centralbl. Bakt., 1* Abt. Orig., xxxvii. (1904) p. 728. 



% Tom. cit., pp. 632-7. 



