42 THE AMERICAN MONTHLY [February, 



tact, otherwise when the gelatine sets the cotton-wool adheres to the 

 tube and becomes a source of embarrassment in subsequent procedures. 

 Care also should be taken not to contaminate by touching or otherwise 

 that part of the plug that belongs within the tube during the process of 

 pouring the gelatine into them. 



After the tubes are filled they should be placed in a wire basket and 

 suspended in a steam sterilizer for ten minutes after the thermometer 

 indicates a temperature of ioo° C. This is repeated each day for three 

 successive days. This has been found sufficient to sterilize the gelatine. 

 If one has not a sterilizer the tubes may be placed in a water bath and 

 be boiled for five minutes each day for three successive days. If the 

 gelatine is boiled too much it will not set upon cooling and is therefore 

 worthless. After the gelatine is sterilized it should be kept in a cool 

 place until used. 



o 



Cultivation of Bacillus Tuberculosis on Potato.* — 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 a temperature 

 of 1 15° C. When withdrawn from the steamer, the tubes are placed 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 C. 



After twelve days' incubation the culture appears. It is whitish and 

 glossy, and shows up distinctly against the yellow color 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 develop with 

 greater rapidity. The pathogenic properties of the bacillus are quite 

 maintained ; rabbits inoculated therewith die in iS 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. 



Spore formation in the Bacillus of Glanders. f — Prof. P. Baum- 

 garten states that Dr. Rosenthal has made numerous experiments to 

 determine the question, previously unsolved, of endogenous spore for- 

 mation in glanders bacillus. Numerous experiments with cover glass 

 preparations from somewhat old potato cultivations of this microbe 

 have shown the presence of spores, the appearances resembling those 

 obtained with anthrax bacillus. Neisser's method for staining spores 

 (one hour's staining in Ehrlich's fuchsin solution in a steam sterilizer 

 at ioo° C.j or 150 C. with dry heat, decolorizing in hydrochloric 

 acid and alcohol, and after staining with methylin blue) was adopted. 

 The spores were colored a deep red, and the rest of the rodlet blue. 

 The spores were for the most part free, but sometimes within the bacilli. 

 It must therefore be considered as settled that glanders bacillus forms 

 spores, but whether always or only under certain conditions remains to 

 be determined. 



* Ann. Instit. Pasteur, ii. 1888, 303. 

 tCentralb f. Bak. u. Parasit., 1888, iii, 397. 



