1 873.] Atmospheric Life Germs. 235 



30th, 1870. The following few lines are a slight sketch of 

 the results ; for particulars the reader must be referred to 

 the " Proceedings of the Royal Society " for 1872, p. 140. 



Tubes cleansed with the greatest possible care, and after- 

 wards heated to redness, were filled with solutions of the 

 same composition as those which it was said by Bastian 

 gave rise to organisms in vacuo after heating to so high a 

 temperature as 150 C; the water and liquids were tested ac- 

 cording to Prof. Tyndall's method with a beam of light. 

 After keeping for twelve months, during which time, on 

 frequent examination with a ray of light, no change was 

 seen to have taken place, drops of the liquids were allowed 

 to run on to slips of glass placed in a bell-jar of hydrogen, 

 such being a space shown to be free from floating matter. 

 The microscope, with a higher power than that employed 

 by Dr. Bastian, showed the solutions to be free from all 

 organisms ; nevertheless, portions let out into previously 

 heated flasks, in a few days invariably became charged with 

 living things. The original tubes, to which only pure air 

 had been admitted, were kept weeks and weeks, and still no 

 signs of life were visible in them ; some of these tubes are 

 in existence now, and still in the same condition. Here, 

 then, were liquids, first, kept in vacuo, secondly, in pure 

 air, thirdly, in ordinary air, and only under the last condition 

 did they become filled with life, and that happened in every 

 case. Without wishing to reflect on the work of anyone, it 

 is simply stating a matter of fact to say, that results in favour 

 of the theory of evolution de novo may be obtained most 

 easily, and the more careless the experimenter the more 

 successful would he be in that direction. We therefore see 

 not only the extreme caution with which statements ad- 

 vancing heterogenesis should be received, but also the over- 

 balancing weight of evidence contained in well-determined 

 facts tending in an opposite direction. 



o 



