174 THE ORIGIN OF LIFE 



The minute bodies visible under the microscope 

 would, if they are insoluble, continue to be visible on 

 warming the slide. Whilst the bodies produced by- 

 barium, strontium, and lead are of a different order 

 of magnitude, and it does not seem that the insolu- 

 bility of the sulphates has after all so very much to 

 do with the formation of cells such as those which 

 have been observed. It can be suggested that, 

 although there may be a cellular structure in all 

 such cases, that structure is due to desiccation, 

 or perhaps liquefaction of the gelatinous medium 

 round the precipitated particle, leaving a vacuole 

 which would collapse on melting, so that the solid 

 particle of precipitate being so small might easily 

 escape notice. But this is just what does not 

 happen, for the precipitate aggregates, and provided 

 the observations are made on the same microscopic 

 slide, there does not appear to be any reason to 

 confuse the two effects. The suggestion is in- 

 telligible if one has not seen the bodies that have 

 been described, but only larger groupings of pre- 

 cipitated particles in excess of salt. 



The action of light on those bodies is equally 

 remarkable, as by exposing them for some hours to 

 strong daylight they completely disappear, but re- 

 appear again if kept in the dark for a day or 

 two. This would not happen to an ordinary pre- 

 cipitate. 



The bodies obtained by Rainey by precipitating 

 carbonate of lime in viscid solutions of glue or 

 gelatin, although also of a different order of magni- 



