82 Infection 



Bacillus coli diminished by daily intoxication with 5 to 

 15 c.c. of alcohol introduced into the stomach through a tube. 



It is a common clinical observation that excessive indul- 

 gence in alcohol predisposes to certain infections, notably 

 pneumonia, and every surgeon knows the danger of pneu- 

 monia after anesthetization with ether. 



(/) Traumatic injury and mutilation of the body are not 

 without effect upon infection. The more extensive the 

 damage done to the tissues, the greater the danger of infec- 

 tion, and the more serious the consequences of infection when 

 it takes place. 



The mutilation of the body by the removal of certain 

 organs is of disputed importance. There is much literature 

 upon the effect of the spleen in overcoming infectious agents, 

 but the experimental evidence seems about equally divided 

 as to whether an animal is more or less susceptible after 

 the removal of this organ than it was before. 



(g) Morbid conditions in general predispose to infection. 

 The frequency with which diabetics suffer from furuncles, 

 carbuncles, and local gangrenous lesions of the skin; the 

 increased susceptibility of phthisics to bronchopneumonia 

 of other than tuberculous origin ; the apparent predisposition 

 of injured joints and pneumonic lungs to tuberculosis; the 

 extensive streptococcus invasions accompanying scarlatina 

 and variola ; the presence of Bacillus icteroides and various 

 other organisms in the blood and tissues of yellow fever 

 patients, and the presence of Bacillus sui pestifer in the 

 bodies of hogs suffering with hog cholera, all show the 

 diminution in the general resisting power of an individual 

 already diseased. 



MIXED INFECTIONS. 



The general prevalence of bacteria determines that few 

 can enter and infect the body of a host without the associa- 

 tion of other kinds. Therefore their operation in the body 

 is subject to modifications produced in them or in the host 

 by these associated organisms. 



In experimental investigations this fact it not infrequently 

 forgotten, and it is often remarked with surprise that the 

 results of inoculation with pure cultures of a bacterium may 

 be clinically different from those observed under natural 

 conditions. 



The tetanus bacillus, which endures with difficulty the 



