112 THE ORIGIN OF LIFE 



able to construct from silicon compounds, ultimately 

 derived from the soil, something akin to silicon pro- 

 toplasm for use in its structure. 



The fact of the existence of silicon alcohol and 

 silicon ethers in which this element replaces car- 

 bon, together with the great similarity of the other 

 compounds into which these two bodies enter, in- 

 duced me to put forward this same supposition 

 in 1872, 1 and to make some tentative experiments 

 with different saline solutions " containing in 

 addition to nitrogen, oxygen, and hydrogen 

 some other element in the place of carbon. The 

 element with which the carbon was replaced was 

 either silicon, boron, chromium, aluminium, or iron." 

 And then there follows this statement : " Except 

 in those in which carbon was replaced by silicon, 

 no living things have been met with in any of 

 these solutions (after they had been boiled and 

 the necks of the flasks had been sealed during 

 ebullition)." The solutions of this order in which 

 organisms were then found were two only, and 

 differed but very slightly from those with which 

 I have been experimenting during the last four 

 years. The ingredients were the same in each 



1 See The Beginnings of Life, vol. ii., Appendix A, p. x. 



