lO^S SUMMAUY OF CUHRENT RESEARCHES RELATING TO 



Milk as a Medium.* — Frl. M. Raskin has mixrlo an elaborate series 

 of experiments on tlio culture of pathogenic micro-organisms on a tirm 

 and transparent basis prepared from milk. From milk three kinds of 

 culture-media may be obtained, (1) where casein is retained, (2) where 

 it is replaced by peptone, or (3) by sodium albuminate. The investi- 

 gator describes the preparation of milk-peptone-gelatin, milk-peptono- 

 agar, milk-casein-gelatin, milk-casein-agar, milk-albumen-gclatin, and 

 milk-alburaen-agar. The media provetl to be very suitable. Eight 

 species of Bacteria were found to flourish, Bacillus mallei, B. typh. 

 abdominalis, Komma bacillus cholerse asiaticse, B. tussis convuls., Staplnjlo- 

 C0CCU8 pyogenes albus, Steph. pyog. aureus, Bacillus anthracis, Pneumo- 

 coccus friedliinderi. 



Cultivation of Bacillus Tuberculosis on Potato.f — Dr. A, D. 

 Pawlowsky cultivates the bacillus of tubercle on potato as follows. 

 Into narrow test-tubes, of the shape devised by Roux, are placed slips of 

 potato. These are then sterilized for half an hour at 115^. When 

 withdrawn from the steamer, the tubes are placed at an angle of 30^, in 

 order to get cool, and also to drain. The potato is then inoculated, the 

 tubes plugged and kept at a temperature of 39°. 



After a dozen days' incubation the culture appears. It is whitish 

 and glossy, and shows up distinctly against the yellow colour of the 

 potato. In 5 to 6 weeks the surface is covered with greyish-white 

 granulations. If glycerinated potato be used, the bacillus seems to 

 devclope with greater rapidity. The pathogenic properties of the 

 bacillus are quite maintained, rabbits inoculated therewith die in 

 18 days. 



The author is of opinion that the reason why other experimenters 

 have failed to propagate the bacillus on potato, is that they have failed 

 to recognize that humidity is an essential condition of the life of this 

 microbe. 



Cultivation of Anaerobic Microbes.^ — M. E. Eoux describes some 

 apparatus for ciiltivating anaerobic microbes. For cultivating in licjuid 

 media, in carbonic acid, or other gases the author uses Pasteur's 

 double tubes, the open ends of which unite in a common narrow glass 

 tube, besides which there is an additional tube at the side for filling 

 purposes. Tlie apparatus having been sterilized, the one test-tube is 

 filled through the side tube with the inoculated nutrient solution, the 

 other with sterile solution, after which the side tubes are melted up. 

 Through the common exit tube the flask is evacuated with an air-pump 

 and then filled with the gas desired. The connecting tube is now 

 melted up. The nutrient tube is for control purposes, but afterwards 

 may be used for another inoculation. 



The simple plan for cultivating anaerobic microbes in solid media is 

 to fill completely pipette-like vessels with gelatin nearly boiling, and 

 then to melt iip the ends. The gelatin is freed from air by the boiling. 

 The tubes are inoculated by breaking off an end and then inserting the 

 platinum needle, after which the end is melted up again. Another 

 method employed is to have test-tubes with a narrow neck and then 

 introduce the gas by means of a capillary tube passing through the 

 cotton-wool plug into the gelatin. This done, the neck is melted up. 



• Biol. Centralbl., viii. (1888) pp. 462-70. 



t Ann. Inatit. Pasteur, iL (1888) p. 315. % Ibid., 1887, No. 2. 



