SPIRILLUM CHOLERA ASIATICS 123 



are continued until very large doses, fatal to unprepared 

 animals, are withstood. The serum now has properties which 

 will neutralize the endotoxins of the plague bacillus, and 

 is called a bactericidal serum. It is said to have also some 

 antitoxic properties that neutralize the small amount of extra- 

 cellular poison of this organism. This serum is used for treat- 

 ment during the attack or for immunizing those exposed. 

 The serum is injected under the skin for preventive purposes, 

 but during an attack it is well to give it into the circulation. 

 Not only is this passive immunity made use of, but for 

 prevention of infection, plague bacilli whose pathogenic 

 properties are destroyed by heat are also injected precisely 

 as has been described for typhoid fever. This "vaccine" 

 prophylactic, and one of the first of such procedures, gives an 

 immunity for a few months. Thus there is an active immuni- 

 zing therapy for plague, and passive immunizing substances 

 can be added to the patient's own defences. Immunity 

 against a subsequent attack always follows plague. 



SPIRILLUM CHOLERA ASIATICS. 



Cholera is an acute inflammatory disease of the small 

 intestines characterized by profuse watery stools, a profound 

 prostration, muscular pains, and high fever. It is caused by 

 the Spirillum choleras asiaticce or cholera spirillum or vibrio. 

 The bacteria enter the body only through the mouth, and 

 settle upon the mucous membrane of the lower part of the 

 small intestine. This they penetrate only as far as the 

 deeper layers of the innermost coat of the tube, and by their 

 growth cause a shedding of the lining. The shreds of the 

 desquamated mucous membrane pass off with the watery 

 discharges and cause the characteristic "rice-water" stools. 

 The bared and congested surface permits absorption of the 

 poisons of the spirillum, the body of which does not itself 

 enter the blood stream. The poison quite frequently has a 

 depressing action upon the heart muscle. It is not quite 



