192 CLINICAL BACTERIOLOGY. 



furnished by the experiments upon human beings that were 

 undertaken in part unintentionally (accidental laboratory- 

 infection), in part intentionally. The introduction of the 

 bacilli into the stomach may be unattended with any effect ; 

 at times it gives rise to more or less intense diarrhea (auto- 

 infection of Pettenkofer and Emmerich) ; in other cases 

 as, for instance, in one reported by Metschnikoff however, 

 it induces true dangerous cholera, with all its clinical symp- 

 toms. The sad fate of a young Hamburg physician is well 

 known, who died of typical cholera after a drop of peri- 

 toneal exudate containing vibrios had entered his mouth 

 in the performance of Pfeiffer's test. Subcutaneous inocu- 

 lation with cholera-bacilli causes in human beings only 

 moderate local symptoms and fever of brief duration. The 

 blood under these circumstances acquires immunizing prop- 

 erties (G. Klemperer). 



A disease resembling cholera can be induced in guinea- 

 pigs by direct introduction of the vibrios into the duodenum, 

 by avoidance of the stomach, after ligation of the choledoch 

 duct ; or by introduction of the bacilli into the stomach 

 after previous alkalinization of the gastric contents by means 

 of soda-solution and injection of two or three cubic centi- 

 meters of tincture of opium into the peritoneal cavity. The 

 object of ligating the choledoch duct, as well as of the in- 

 jection of the opium, is to inhibit the peristaltic activity of 

 the intestine. Similar morbid manifestations cholera-like 

 stools, decline of temperature, etc. can be induced in 

 guinea-pigs and rabbits by intravenous introduction of the 

 comma-bacilli, especially after previous intoxication with 

 alcohol, or by simultaneous injection of comma-bacilli and 

 metabolic products of varieties of proteus. 



Intraperitoneal injection of virulent cholera -vibrios is fol- 

 lowed in guinea-pigs (a platinum loopful containing about 

 2.5 mg. of bacterial colonies scraped from the surface of 

 agar-agar for a guinea-pig weighing from 300 to 500 grams) 

 by death, preceded by paralytic phenomena and rapid de- 

 cline of temperature. There takes place under these con- 

 ditions, as has already been stated, an intoxication with the 

 poisons contained within the bodies of the comma-bacillus 

 (p. 189). In the digestive tract of guinea-pigs destroyed 

 by this means special changes are usually not to be 

 observed. At times, the large bowel is markedly injected 

 and the small intestine is not rarely filled with grayish fluid 



