Cultivation 



667 



compounds, especially upon acid potato mixed with glycerin 

 Rosenau* has shown that it can grow upon almost any cooked and 

 glycerinized vegetable tissue. 



Animal Tissues. — Frugonif recommends 

 that the tubercle bacillus be isolated and 

 cultivated upon animal tissue and organs 

 used as culture-media. He especially 

 recommends rabbit's lung and dog's lung 

 for the purpose. The tissues are first 

 cooked in a steam sterilizer, then cut into 

 prisms, placed in a Roux tube, an addition 

 of 6 to 8 per cent, glycerin-water added, 

 so as to bathe the lower part of the tissue 

 and keep it moist, and the whole then 

 sterUized in the autoclave. 



The organisms are planted upon the 

 tissue, the top of the tube closed with a 

 rubber cap, and the culture placed in the 

 thermostat. The tubercle bacilli grow 

 quickly and luxuriantly. 



Bouillon. — Upon bouillon to which 6 per 

 cent, of glycerin has been added the bacillus 

 grows well, provided the transplanted 

 material be in a condition to float. The 

 organism being purely aerobic grows only 

 at the surface, where a much wrinkled, 

 creamy white, brittle pellicle forms. 



Non-albuminous Media. — Instead of re- 

 quiring the most concentrated albuminous 

 media, as was once supposed, Proskauer 

 and BeckJ have shown that the organism 

 can be made to grow in non-albuminous 

 media containing asparagin, and that it 

 can even be induced to grow upon a mix- 

 ture of commercial ammonium carbonate, 

 0.35 per cent.; primary potassium phos- 

 phate, 0.15 per cent.; magnesium sul- 

 phate, 0.25 percent.; glycerin, 1.5 percent. 

 Tuberculin was produced in this mixture. 



Gelatin. — ^The tubercle bacillus can be 



grown in gelatin to which glycerin has 



been added, but as its development takes 



place only at 37° to 38°C., a temperature 



at which gelatin is always liquid, its use for the purpose has no 



advantages. 



* "Jour. Amer. Med. Assoc," 1902. 



t "Centralbl. f. Bakt. u. Parasitenk.," I. Abl. Orig., 1910, liii, sS3- 



t "Zeitschrift Wr Hygiene," Aug. 10, 1894, xvm, No. i. 



Fig. 274. — Bacillus tu- 

 berculosis; glycerin agar- 

 agar culture, several 

 months old (Curtis). 



