1870.] with Recent Experiments. 489 



peated with such satisfactory results. The glasses containing the 

 water were so placed in a box divided by three partitions and covered 

 with lids of blue, red, and yellow glass, that the panes intercepted 

 all dust falling perpendicularly, and for several days very little dust 

 reached the contained water. A deposit of dust had meanwhile 

 accumulated on the panes of glass. Finding little or no life in the 

 distilled water, I washed the dust from the glass lids into the re- 

 spective vessels, and on the following day repeated the examination. 

 As usual, I observed particles of silex and fragments of organic sub- 

 stances, and, with a low power, these seemed to be imbedded in a 

 gelatinous film. I had placed the little glass vessels themselves 

 under the instrument, and after pouring off the water, examined the 

 deposit with a power of about fifty diameters. On covering the 

 sediment with a thin glass, and bringing a higher power to bear, 

 I found the gelatinous film to consist of motionless transparent 

 monads or cells, and carefully restoring the contents of the vessels, 

 pouring back the water, I left them until the following day. Dur- 

 ing the night and day, the cells or monads had become endowed 

 with rapid motion, and an examination of the water showed it to 

 be peopled with myriads of active moving germs." 



Here, then, is another phenomenon supposed to be attendant 

 upon the creation de novo of lowly organisms in infusions, which I 

 had observed and recorded years since in pure distilled water ex- 

 posed to atmospheric action. 



And this brings me to my recent investigations, conducted 

 during the months of June, July, and August last. As considerable 

 doubt has been thrown upon the existence of germs in the atmo- 

 sphere by certain observers, in their anxiety to prove the sponta- 

 neous production of the lowest plants and animals, I first repeated 

 my former simple experiments with distilled water, and this time I 

 used open saucers, small glass well-dishes (those used to hold ink), 

 and even test tubes. 



On the 21st June I first exposed two saucers of distilled water 

 to the air, and two days afterwards I found it to contain a little 

 sediment of dust. On examination with the microscope, a drop of 

 the water presented the appearance so frequently described by me. 

 There were fragments of silex, soot, and minute moving germs. 

 The latter I shall not attempt to dignify with scientific names; 

 suffice it to say that the contrast between their movements and the 

 molecular motions of particles of organic and inorganic matter af- 

 forded sufficient proof of their being endowed with life. I then filled 

 two test-tubes with portions of this water, closed the opening of 

 one with a sheet of cotton- wool, and left the other exposed to the 

 air. From the 23rd June to the 5th July the weather was cold 

 and rainy, conditions very unfavourable for the development of 

 living germs ; but between the 5th and 7th July the temperature 



