Pathogenesis 781 



teolytic ferments. There is no exotoxin. All the poisonous 

 substances seem to be endotoxins. 



Mallein. Babes,* Bonome,f Pearson, J and others have 

 prepared a substance, mallein, from cultures of the glanders 

 bacillus, and have employed it for diagnostic purposes. It 

 seems to be useful in veterinary medicine, the reaction fol- 

 lowing its injection into glandered animals being similar to 

 that caused by the injection of tuberculin into tuberculosis 

 animals. The preparation of mallein is simple. Cultures of 

 the glanders bacillus are grown in glycerin bouillon for sev- 

 eral weeks and killed by heat. The culture is then filtered 

 through porcelain, to remove the dead bacteria, and evapo- 

 rated to one-tenth of its volume. Before use the mallein is 

 diluted with nine times its volume of 0.5 per cent, aqueous 

 carbolic acid solution. The dose for diagnostic purposes is 

 0.25 c.c. for the horse. It has also been prepared from 

 potato cultures, which are said to yield a stronger product. 

 The agent is employed exactly like tuberculin, the tem- 

 perature being taken before and after its hypodermic injec- 

 tion. A febrile reaction of more than 1.5 C. is said to be 

 indicative of the disease. 



Pathogenesis. That the bacillus is the cause of glanders 

 there is no room to doubt, as LofHer and Schutz have suc- 

 ceeded, by the inocultion of horses and asses, in producing 

 the well-known disease. 



The goat, cat, hog, field-mouse, wood-mouse, marmot, 

 rabbit, guinea-pig, and hedgehog all appear to be susceptible. 

 Cattle, house-mice, white mice, rats, and birds are immune. 



Infection may take place through the mucous membranes 

 of the nose, mouth, or alimentary tract, and apparently 

 without pre-existing demonstrable lesions. 



The disease assumes either an acute form, characterized by 

 destructive necrosis and ulceration of the mucous membranes 

 with fever and prostration, terminating in pneumonia, or, 

 as is more frequent, a chronic form (" farcy "), in which the 

 lesions of the mucous membranes are less destructive and in 

 which there is a generalized distribution of the micro-organ- 

 isms throughout the body, with resulting more or less wide- 

 spread nodular formations (farcy-buds) in the skin. The 



* "Archiv. de Med. exp. et d'Anat. patholog.," 1892, No. 4. 

 t "Deutsche med Woch.," 1894, Nos. 36 and 38, pp. 703, 725, and 744. 

 t "Jour, of Comp. Med. and Vet. Archiv.," Phila., xn, 1891, pp. 

 411-415. 



