276 PATHOGENIC BACTERIA. 



of guinea-pigs the peristaltic movements are checked. 

 The amount given for the purpose is very large, about 

 i gram for each 200 grams of body-weight. It generally 

 narcotizes the animals for a short time, but they recover 

 without injury. After administering the opium the con- 

 tents of the stomach are neutralized by introducing 

 through a pharyngeal catheter 5 c.cm. of a 5 per cent, 

 aqueous solution of sodium carbonate. With the gastric 

 contents thus alkalinized and the peristalsis paralyzed a 

 bouillon culture of the spirilla is introduced. The ani- 

 mal recovers from the manipulation, but shows an indis- 

 position to eat, is soon observed to be weak in the pos- 

 terior extremities, subsequently is paralyzed, and dies 

 within forty-eight hours. The autopsy shows the intes- 

 tine congested and filled with a watery fluid rich in spi- 

 rilla an appearance which Frankel declares to be exactly 

 that of cholera. In man, as well as in these artificially 

 injected animals, the spirilla are never found in the blood 

 or the tissues, but only in the intestine, where they fre- 

 quently enter between the 'basement membrane and the 

 epithelial cells, and aid in the detachment of the latter. 



Guinea-pigs are also susceptible to intraperitoneal in- 

 jections 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-organism, 

 and injection and redness of the peritoneum and viscera. 



Although in reading upon cholera at the present time 

 we find very little skepticism in relation to Koch's 

 " comma bacillus," we do find occasional doubters who 

 believe with Von Pettenkoffer that the disease is mias- 

 matic. PettenkofFer's theory is that the disease has 

 much to do with the ground-water and its drying zone. 

 He regards as the principal cause of the disease the de- 

 velopment of germs in the subsoil moisture during the 

 warm months, and their impregnation of the atmosphere 

 as a miasm to be inhaled, instead of ingested with food 

 and drink. This idea of PettenkofFer's, combined with 



