48 BACTKRIOLOGY. 



and insoluble in ether, chloroform, and benzine. It is a yellowish 

 amorphous body, becoming a deep brown when made alkaline. 



Martin concludes that whereas the Bacillus anthracis produces 

 albumoses and an organic base, in diphtheria we find albumoses and 

 an organic acid. 



Glanders.^ — Kalming has obtained from cultures of the glanders 

 bacillus an extract similar to tuberculin. This crude extract is 

 known as mallein, and is extensively used for the diagnosis of 

 glanders. In a glandered horse it causes a rise of temperature 

 and swelling at the seat of the injection, and the glandered nodules 

 become swollen and painful. Finger claims to have produced 

 immunity from glanders by inoculation of the products contained 

 in sterilised cultures. Schweinitz extracted from cultures a non- 

 poisonous albumose, and obtained onl)' traces of a ptomaine. 



Suppuration and Pneumonia. — Brieger obtained a ptomaine 

 from cultures of Staphylococcus pyogenes aureus, and Eoux and 

 Yersin a tox-albumin fatal to rabbits and guinea-pigs in a few 

 days. There was pus-formation at the seat of inoculation, with 

 redness and swelling of the surrounding parts. 



From pure-cultures of the micrococcus of pneumonia Klemperer 

 obtained a tox-albumin, for which the name pneumo-toxin has been 

 suggested. 



Enzymes or Ferments. 



Many bacteria liquefy the nutrient gelatine m which they are 

 cultivated. This is due to the development of a ferment or enzyme, 

 which dissolves the albumin and gelatine. 



Enzymes are products of the vital activity of living bacteria. 

 Bitter, and independently Sternberg, showed that when a liquefying 

 bacterium is removed by filtration or destroyed by heat, the culture 

 fluid retains the power of liquefying gelatine. As this occurs 

 usually when the reaction is alkaline, bacterial enzymes resemble 

 trypsin and papain rather than pepsin. They can be extracted with 

 glycerine, and are quite harmless. If injected into animals no effect 

 is produced, and after a few hours no trace of them can be found. 

 According to Fermi, the influence of temperature on the enzymes 

 produced by different bacteria will be found to vary very consider- 

 ably. The enzyme of Staphylococcus pyogenes aureus is destroyed 

 at 55° C, while the enzyme of Bacillus anthracis succumbs at n 

 temperature of 65° 0. to 70° C. 



Some bacteria produce both enzymes and toxins, hut many pro- 

 duce enzymes and not toxins, and others toxins but not enzymes 



