742 



MODE OF SPREAD OF INFECTIVE DISEASES. 



This question 

 was formerly 

 answered in 

 the affirmative 

 in the case of 

 the intestine 

 and lung's. 



The .sapro- 

 phytes are 

 supposed to 

 die in the 

 Wood. 



This assump- 

 tion is in- 

 correct, 



This question has or the most part been answered in 

 the affirmative. The passage of oil globules through 

 the walls of the intestine, and the enormous surface and 

 delicate epithelial covering of the lung, has been promi- 

 nently pointed out ; and the constant entrance of sapro- 

 phytic bacteria, and the occasional passage of infective 

 agents into the interior of the body, especially into the 

 circulating blood, has been assumed. Pettenkofer has 

 indicated the lungs as the chief organ through which 

 the pathogenic bacteria pass into the blood ; according 

 to the view generally held, they are then carried from 

 the lungs to those parts of the body in which the local 

 affections characteristic of the disease in question usually 

 appear. Thus the infective agents of cholera and typhoid 

 fever, when they are inhaled, are supposed to pass 

 through the lungs into the blood, and from thence into 

 the mucous membrane of the intestine, where they 

 multiply and set up the specific alterations. 



The fact that no bacteria have been found in the 

 interior of the healthy body in various careful investiga- 

 tions is opposed to the view that saprophytic bacteria are 

 constantly penetrating into the normal body from the 

 lungs and intestine. Von Fodor and others have, how- 

 ever, sought to explain this contradiction by the assump- 

 tion that the saprophytic organisms which pass into the 

 body are rapidly destroyed in the blood. 



Such an explanation is, however, no longer admissible 

 after the researches of Wyssokowitsch, to which we have 

 previously alluded. These investigations have shown 

 that a great variety of bacteria are not destroyed in the 

 circulating blood, but retain their vitality in the interior 

 of certain organs for several hours, days, or even months. 

 If, therefore, there were a constant passage of bacteria 

 from the lungs and intestines into the blood, we must 

 undoubtedly frequently find them in considerable n am- 

 bers in the interior of the body, and the resistant subtilis 

 spores which are always present on the surface of the 

 body would gradually accumulate in the body. 



As the result of these experiments it is very impro- 

 bable that bacteria can pass through the mucous mem- 



