72 POPULAR SCIENCE MONTHLY. 



INFECTIOUS DISEASES. 



By ALFRED SPRINGER, PH.D., 

 CINCINNATI, OHIO. 



INFECTIOUS diseases have devastated more homes than all wars 

 combined, and a check to their ravages would be the greatest boon 

 suffering mankind can hope to achieve. 



These diseases are supposed to owe their origin to the activity of 

 ferments, enzymes, sporozoa or other ultra-microscopical organisms, con- 

 sequently they must have some reactions in common with other 

 phenomena depending upon the same agencies. 



If true scientific reasoning is based upon inductive methods, namely, 

 'the endeavor from the much which is observable to arrive at a little 

 which may be verified and is indubitable' then truly our knowledge of 

 ferments is very meager — in fact practically everything we know is 

 deduced from observing the alcoholic yeast ferments, and this for the 

 following reasons: First, they have been employed for many ages. 

 Second, they are larger than the other ferments. Third, they can be 

 studied without jeopardizing fellowmen. Fourth, their chemical effects 

 can be traced in the laboratory, qualitatively and quantitatively, an I 

 last, but not least, their study is not beset with those difficulties which 

 immediately present themselves when effects are produced upon higher 

 differentiated types such as man. 



I shall only call attention to such properties which undoubtedly 

 many pathogenic bacteria hold in common with them, namely, we know 

 that these ferments multipty with exceeding rapidity — that they can 

 withstand great ranges of temperature and many chemicals poisonous 

 to man — that they can accommodate themselves to abnormal conditions 

 and remain dormant until suitable conditions again arise and that by 

 their immense numbers much organic material is destroyed. We know, 

 on the other hand, that these ferments have their enemies which can 

 either suppress them entirely or to such an extent as to make them 

 harmless. We know that the introduction of other ferments in the same 

 medium, making use of one of their essential nutrients, may cause 

 a total cessation of their activity — we know that their own excreta or 

 similar products act as poisons upon them. We also know that ferments 

 and enzymes are selective in their foods, probably not from volition, 

 but for reasons of food assimilation. 



It is a well-known fact that but an imponderable quantity of a 

 specific ferment is required to start fermentation and this, owing to 



