398 BACILLI IN CHRONIC INFECTIOUS DISEASES. 



per-cent solution of acetic acid to which sufficient tropseolin has 

 been added to give it the yellow color of Rhine wine ; then quickly 

 washed in distilled water. This bacillus presents the peculiarity of 

 losing very quickly in decolorizing solutions the color imparted to it 

 by the aniline staining solutions. For this reason the staining of the 

 bacillus in sections is attended with some difficulty. Loffler recom- 

 mends his alkaline methylene-blue solution for staining sections ; and 

 for decolorizing, a mixture containing ten cubic centimetres of distilled 

 water, two drops of strong sulphuric acid, and one drop of a five- 

 per-cent solution of oxalic acid. Thin sections should be left in this 

 acid solution about five seconds. The method more recently recom- 

 mended by Kuhne also gives good results in skilful hands (see p. 34). 



Biological Characters. An aerobic, non-motile, parasitic 

 bacillus, which may be cultivated in various artificial media at a 

 temperature of 37 C. The lowest temperature at which develop- 

 ment occurs (22 C. Loffler) is a little above that at which nutrient 

 gelatin is liquefied ; the highest limit is 43 C. According to Frankel, 

 the glanders bacillus is a facultative anaerobic. Baumgarten and 

 Rosenthal claim to have demonstrated the presence of spores by 

 Neisser's method of staining. Loffler was led to doubt the forma- 

 tion of spores from the results of his experiments upon the thermal 

 death-point of this bacillus, and its comparatively slight resistance 

 to desiccation and destructive chemical agents. He found that ex- 

 posure for ten minutes to a temperature of 55 C., or for five minutes 

 to a three- to five-per-cent solution of carbolic acid, or for two min- 

 utes to a 1 : 5,000 solution of mercuric chloride, was effectual in de- 

 stroying its vitality. As a rule, the bacilli do not grow after having 

 been preserved in a desiccated condition for a few weeks ; and in a 

 moist condition the cultures cannot be preserved longer than three 

 or four months usually not so long as this (Loffler). The bacillus 

 does not grow in infusions of hay, straw, or horse manure, and it is 

 doubtful whether it finds conditions in nature favorable for its sap- 

 rophytic existence. It grows, in the incubating oven, in neutral 

 bouillon, in nutrient gelatin, or in nutrient agar, and still better in 

 glycerin-agar. Upon the last-mentioned medium it grows, even at 

 the room temperature (Kranzfeld), but better still in the incubating 

 oven, as a pale- white, transparent streak along the line of inocula- 

 tion, which at the end of six or seven days may have a width of 

 seven to eight millimetres. According to Raskina, nutrient agar 

 made with milk forms an extremely favorable medium, upon which 

 a thick, pale- white layer develops in two or three days, which on the 

 third or fourth day acquires an amber-yellow color, and the deeper 

 layers acquire a brownish-red tint. 



The growth upon solidified blood serum, in the course of three or 



