Pathogenesis 617 



the peristaltic movements of the intestine can be checked. The 

 amount necessary for the purpose is large and amounts to about 

 I gram for each 200 grams of body-weight. It completely nar- 

 cotizes the animals for a short time (one to two hours), but they re- 

 cover without injury. The contents of the stomach are neutrahzed 

 after administering the opium, by introducing 5 cc. of a 5 per cent, 

 aqueous solution of sodium carbonate through a pharyngeal catheter. 

 With the gastric contents thus alkalinized and the peristalsis para- 

 lyzed, a bouillon culture of the cholera spirillum is introduced through 

 Ihe stomach-tube. The animal recovers from the manipulation, 

 but shows an indisposition to eat, is soon observed to be weak in the 

 posterior extremities, subsequently is paralyezd, and dies within 

 forty-eight hours. The autopsy shows the intestine congested and 

 filled with a watery fluid rich in spirilla — an appearance which 

 Frankel declares to be exactly that of cholera. In man, as well as in 

 these artificially infected animals, the spirilla are never found in the 

 blood or tissues, but only in the intestine, where they frequently 

 enter between the basement membrane and the epithelial cells, and 

 aid in the detachment of the latter. 



IssaefE and Kolle found that when virulent cholera spirilla are 

 injected into the ear-veins of young rabbits the animals die on the 

 following day with symptoms resembUng the algid state of human 

 cholera. The autopsy in these cases showed local lesions of the 

 small intestine very similar to those observed in cholera in man. 



Guinea-pigs are susceptible to intraperitoneal . injections of 

 the spirillum, and speedily succumb. The symptoms are rapid 

 fall of temperature, tenderness over the abdomen, and collapse. 

 The autopsy shows an abundant fluid exudate containing the micro- 

 organisms, and injection and redness of the peritoneum and viscera. 

 Specificity. — ^The cholera spirillum is present in the dejecta 

 of cholera with great regularity, and as regularly absent from the 

 dejecta of healthy .individuals and those suffering from other 

 diseases. No satisfactory proof of the specific nature of the organ- 

 isms can be obtained by experimentation upon animals. Ani- 

 mals are never affected by any disease similar to cholera during 

 epidemics, nor do foods mixed with cholera discharges or with pure 

 cultures of the cholera spirillum affect them. Subcutaneous in- 

 oculations do not produce cholera. 



A sufficient number of laboratory infections have occurred among 

 human beings, however, to be convincing. Such have been reported 

 by Koch,* Metchnikoff,t Hasterlik,t E.enners,§ Kolle,|| Voges,** 

 Zeatogoroffft and others. 



* "Deutsche med. Wochenschrift," 1885, 37a, p. 7. 



t "Ann. de I'lnst," Pasteur, 1893, vn, 403; 562. 



j "Wiener klin. Wochenschrift," 1893, p. 167. 



§ "Deutsche med. Wochenschrift," 1894, 52. 



II "Zeitschrift ftir Hygiene," 1894, xvm, 17. 

 ** "Centralbl. f. Bakt. u. Parasitenk.," 1895, xvin, 629. 

 tt "Berliner klin. Wochenschrift," 1909, No. 44. 



