GLANDERS GROUP 259 



precipitate is washed in alcohol, then in ether, and dried. The 

 diagnostic dose is 0.02 to 0.03 gm. It is prepared for injection by 

 dissolving in a mixture of glycerin and water. 



The malleinum siccum, or dried mallein, of Foth is prepared 

 by growing B. mallei in 4.5 per cent, glycerin broth. The cultures 

 used are rendered virulent by passage through cats, guinea-pigs, 

 and field-mice. The material is incubated at 37.7 for three 

 weeks. It is concentrated, and the organism killed by evapora- 

 tion at a constant temperature of 76 to 80 to one-tenth of its 

 former volume. This is filtered and poured into absolute alcohol, 

 in which a precipitate immediately forms. This precipitate is 

 washed in alcohol and dried in a desiccator. The final product 

 is a white powder which readily dissolves in water. The diag- 

 nostic dose for the horse is 0.045 to 0.05 gm. 



The mallein prepared in the laboratories of the Bureau of Animal 

 Industry consists of glycerinated broth in which the B. mallei 

 has grown four to five months, has been heated, concentrated, and 

 filtered. It is diluted by the addition of one-half its volume of 

 glycerin and one and one-half times its volume of 1 per cent, 

 phenol. The diagnostic dose is 1 c.c. 



No practicable method of standardizing mallein has been 

 worked out other than trial upon a considerable number of healthy 

 and infected animals. The variations in the methods of produc- 

 tion of mallein given above are due to a desire to secure a very 

 uniform product. 



Mallein, when injected in the correct diagnostic dose, some- 

 times causes in a healthy animal a slight fever reaction of short 

 duration, with frequently a transitory swelling at the point of 

 injection. When injected into a glandered animal, the tempera- 

 ture begins to rise in six to eight hours. At the site of injection 

 there is developed a swelling, painful, hot, and of considerable size, 

 and extending along the lymphatics for some distance. It persists 

 several days, and disappears in a week or ten days. Constitu- 

 tional symptoms of the reaction, such as dejection of the patient, 

 lusterless coat, anxious expression, impaired appetite, and hurried 

 respiration are usually valuable aids in recognizing a reaction. 



When properly carried out, the mallein test is valuable as a 

 diagnostic method for glanders. 



