ORIGIN OF LOWEST ORGANISMS. 



air contains any notable quantity of living Bacteria, 

 or Bacteria germs, whether visible or invisible. I 

 have always found that a simple solution of ammonic 

 tartrate, which has been placed without previous 

 boiling in a corked bottle of greater capacity, will 

 become turbid in two or three days, owing to the 

 presence of myriads of Bacteria; whilst a similar 

 solution, previously boiled, may remain for ten days, 

 three weeks, or more, without showing the least trace 

 of turbidity, although the open neck of the bottle or 

 flask in which it is contained, may be covered only by 

 a loose cap of paper. And yet, at any time, in order to 

 make this fluid become turbid in from 24 to 48 hours, 

 all that one has to do is to bring it into contact with 

 a small glass rod which has just been dipped into a 

 solution containing living Bacteria* 



If we find that an eminently inoculable fluid will 

 remain for two or three weeks, or perhaps more, 

 in contact with the air without becoming turbid, 

 though it will always become turbid in two or three 

 days if brought into contact with living Bacteria, what 

 can we conclude, but that living Bacteria are not very 

 common in the atmosphere ? These most striking 

 facts can be easily verified by other observers. 



Thus we find ourselves, at present, in this position. 

 After all that has been said and done to prove the 

 wonderful prevalence of " germs ' in the atmosphere, 



* The solution, during the whole time, being exposed to a 

 temperature of 75 to 85 F. 



