88 BACTERIAL POISONS. 



thought that the symptoms and death are due to stoppage 

 of the pulmonary escalation by means of emboli. How- 

 ever, HOFFA studied this point by making numerous post- 

 mortem examinations, and was unable to confirm it. A 

 like result followed the work of YIRCHOW, COLIN, and 

 SIEDAMGROTZKY, and the mechanical-interference theory 

 has been abandoned. 



In the majority of germ diseases this theory never had 

 any support. There is not found any great accumulation 

 of bacteria in any organ, and the number and distribution 

 of the germs are such that the theory of mechanical inter- 

 ference cannot be held. 



3. Another answer given to the question, How do germs 

 cause disease? is, that they do so by consuming the proteids 

 of the body and thus deprive it of its sustenance. The 

 proteids are known to be necessary for the building up of 

 cells, and it is also known that microorganisms feed upon 

 proteids. But this theory is untenable for several reasons. 

 In the first place, many of the infectious diseases destroy 

 life so quickly that the fatal eifect cannot be supposed to 

 be due to the consumption of any very large amount of 

 proteids. In the second place, the distribution of the micro- 

 organisms is such in many diseases that they do not come 

 in contact with any large proportion of the proteids of the 

 body. In the third place, the symptoms of the majority of 

 these diseases are not those which would be produced by 

 withdrawing from the various organs their food. The 

 symptoms are not those of general starvation. 



4. Still another theory, which has been offered, is that 

 the bacteria destroy the blood corpuscles, or lead to their 

 rapid disintegration. But in many of the infectious dis- 

 eases, as has been stated, the microorganisms, although very 

 abundant in some organs, are not present in the blood. 

 Moreover, the disintegration of the blood corpuscles is not- 

 confirmed by microscopical examination. 



5. Seeing the vital deficiencies in the above theories, and 

 being impressed by the results obtained by the chemical 

 study of putrefaction, bacteriologists have been led to in- 

 quire into the possibility of the symptoms of the infectious 



