HOW LIFE CAME TO EARTH 195 



organisms were more plentiful when the 

 sealed tubes were exposed during these 

 months to diffuse daylight. This appears 

 to have been an incidental experience, but 

 if these results of Bastian are real, it is obvious 

 that some such form of energy must be made 

 available in order that organic may arise from 

 inorganic matter. Some batches of tubes 

 were indeed found to engender more imper- 

 fectly in an incubator, but this incubator was 

 heated by an incandescent electric light 

 placed within it so that a source of radiant 

 energy was available here also. 



It is also to be noted that the composition 

 of the two fluids for which success is claimed, 

 happens to be just that which will throw the 

 silicic acid, or mixture of silicic acid and 

 ferric oxide, into the condition of a labile 

 colloid most favourable for energy capture. 



In the first solution mentioned above, the 

 sodium silicate on account of its alkalinity is 

 non-colloidal, but to this is added a small 

 amount of phosphoric acid in presence of a 

 small amount of ammonium phosphate. This 

 addition will just give that faint acidity which 

 will make the colloidal silicic acid appear, 

 without, on the other hand, being so acid as 

 to throw the colloid out of solution. In the 

 case of the second solution, the ferric ni: 



