ORGANIC CHEMISTRY 459 



necessary here to attempt to follow the transformations of the 

 starch thus deposited in order that it may become available as 

 food for the plant. It is only necessary to state that it is obvious 

 that grains of starch being insoluble in water, this substance 

 must be changed into something which is soluble, so that it may 

 pass by diffusion from cell to cell in the tissue. It has been 

 shown that this soluble compound is a sugar, and that it is 

 formed from the starch by the action of an enzyme associated 

 with the living protoplasm. 1 



Observations of this kind have led to various attempts to 

 effect the change by which, from carbonic acid and water, 

 formaldehyde and oxygen are formed, without the aid of the 

 living plant and by the use alone of inorganic materials, the 

 necessary energy required to bring about the reaction being 

 derived from the sun. This result is said to have been achieved 

 by several workers, of whom the most recent, Professor Benjamin 

 Moore and Mr. T. A. Webster, in a paper contained in the 

 Proceedings 2 of the Royal Society, review and partly confirm 

 the results of earlier workers in the same field. 



The materials used in these researches consisted of an aqueous 

 solution of carbon dioxide mixed with a solution of colloidal 

 uranic hydroxide or ferric hydroxide (see Colloids). The mixed 

 solutions were exposed to the rays of the sun for one or two days 

 or more, and at the end of the exposure the liquid was distilled 

 and tested, by methods known to be very sensitive, for the 

 presence of formaldehyde. 



Similar solutions kept in the dark gave no indication of the 

 production of any such substance. Now as it has been shown 

 repeatedly that formaldehyde in the presence of lime or of 

 certain salts of inorganic nature and origin condenses somewhat 

 readily into various sugars, here is a process by which it is con- 

 ceivable that a so-called organic compound might be formed by 

 a natural operation independently not only of living matter, but 

 of the artificial conditions provided by the intervention of man. 



For the essence of the process is the occurrence together of 

 water, carbon dioxide, and some colloidal or other substance 

 which may act as a catalyst in the presence of solar radiation^ 



1 The reader who is interested in such questions should read Brown and 

 Morris, "On the Chemistry and Physiology of Foliage Leaves," Trans. Chem. 

 Soc., 1893, pp. 604-677. 



a Proc. Hoy. Soc., 87 B, 163 (1913). 



