104 ESSENTIALS OF BACTERIOLOGY. 



staining ; those that do not take the stain are alone retained. 

 Cultures are made from these upon potatoes, and, if the char- 

 acteristic growth occurs, then only can they be called typhoid 

 bacilli with any certainty. 



Patfiogenesis. Lower animals have not yet been given enteric 

 fever, though their death has been caused by injection of the 

 bacilli into the veins of the ear. 



In man it has been found in the urine, blood, sputum, milk, 

 intestinal discharges, roseolar spots, and in various organs, as 

 spleen, liver, lymphatic glands, and intestinal villi. 



It is found in secretions several days after the attack has sub- 

 sided. It is found only in this disease, and regularly. 



Way of Infection. The bacilli in the dejecta of the diseased 

 person find their way into drinking water, milk, or dirty clothes, 

 and so into the alimentary tract of a person predisposed to the 

 disease. They enter the blood through the lymphatics, and so 

 become lodged in various organs. 



Products. Brieger found a ptomaine in the cultures which he 

 named typhotoxin with the formula C 9 H 17 NO 2 . It has no 

 specific action. A toxalbumen insoluble in water has also been 

 isolated, but, as experiment animals are immune to the disease, 

 no definite actions have yet been determined. 



The cultures, when old, show an acid reaction. 



Bacillus Neapolitanus. (Emmerich.) 



Origin. During the cholera epidemic in Naples, in 1884, 

 Emmerich found this bacillus in the blood and intestinal dis- 

 charges of cholera-suffering patients. He supposed it to be the 

 real cause of cholera ; but since then it has been shown to he 

 nothing more than the Faeces bacillus which Brieger described, 

 and which is found in faeces of healthy persons, in the air and 

 various putrefactive processes. 



Form. Very much like the typhoid bacillus, short rods with 

 rounded ends with oval spaces in them as the typhoid. 



Properties. Immobile, differing thus markedly from typhoid. 

 Do not liquefy gelatine. 



Growth. They are facultative anaerobic ; they grow more 

 rapidly than the typhoid, and endure cold and heat better than 

 they do. 



