2Q4 BACTERIOLOGY. 



acid. By embedding" material containing bacilli in 

 nutrient agar-agar and nutrient gelatine, charac- 

 teristic cultivations are obtained. The following 

 process may be adopted to obtain a pure cultiva- 

 tion.* A mouse inoculated subcutaneously with 

 dust, as a rule, dies in one to two days. It is then 

 pinned out, back uppermost, on a slab of wood 

 (p. 113), and the hair singed with a Paquelin's 

 cautery from one hind leg up to the neck, across 

 the latter, and down again to the opposite hind 

 leg. Following the cauterised line, the skin is cut 

 through with sterilised scissors, and the flap turned 

 back and pinned out of the way. With curved 

 scissors little pieces of the subcutaneous cedema- 

 tous tissue, in the neighbourhood of the inoculated 

 spot, are cut out, and sunk with a platinum needle 

 in a i per cent, nutrient agar-agar, or 5 per cent, 

 nutrient gelatine. Fragments of tissue may also 

 be embedded by the method already described 



(P- 137). 



The inoculated tubes are placed in the incubator. 



In a few hours a whitish turbidity spreads out from 

 the piece of tissue, and upwards in the needle track. 

 Examined microscopically, the turbidity is found to 

 be due solely to the development of bacilli of oedema. 

 The surface exposed to the air exhibits no trace 

 of the bacilli. 



To investigate the tubes microscopically, a steri- 

 lised glass tube with a capillary end may be used, 



* Hesse, Deutsch. Med. Woch., No. 14. 1885. 



