THE BEGINNINGS OF LIFE. 



certain kind, there is no absolute improbability in the suppo- 

 sition that the carbon usually existing in the living compound 

 might be replaced by some other element. With the hope 

 of throwing some little light upon this very difficult subject, 

 I made several tentative experiments with 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 1 . 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). This result taking it merely for what it is 

 worth is extremely interesting and suggestive, since 

 silicon is certainly the element which most closely resembles 

 carbon, and which might therefore best replace it in com- 

 pounds otherwise similar to those which constitute the basis 

 of living matter. A silicon alcohol and ether has in fact been 

 produced by Professor Wohler 2 , in which the carbon of the 

 ordinary compounds is replaced by silicon. It is therefore 

 deemed quite possible that silicon may take the place of 

 carbon in certain forms of living matter. No absolute proof 

 of this, however, can at present be advanced. What follows 

 must be taken merely as an indication of the possibility of 

 such an occurrence. 



In the first place (though it is a fact which I have only 

 quite recently observed), minute fungoid organisms have been 

 found growing at the surface of a solution of silicate of soda 

 in a tolerably luxuriant manner. About half an ounce of this 

 fluid was contained in a corked i oz. phial, which had not 



1 As I have already stated, these experiments were merely tentative. 

 It is not supposed that solutions were employed free from all trace of 

 carbon, existing as an impurity. 



2 ' Ann. Ch. Pharm.' cxxvii., and civ. 



