﻿CATALYSIS. 137 



acetaldehyde and pyruvic acid CH 3 .CO.COOH were detected, the pres- 

 ence of the latter being determined by obtaining the phenvlhydrazone 

 melting at 188°. 



Pyrotartaric acid is also markedly decomposed, carbon dioxide being 

 evolved, and n-butyric and isobutyric acids remaining; malic and lactic 

 acids both give carbon dioxide and probably acetaldehyde, but the other 

 products have not yet been determined. It is not unreasonable to 

 suppose that the first decomposition product formed by the action of a 

 uranium salt in the sunlight on malic acid, is lactic acid which is then 

 further broken down to give acetaldehyde and formic acid. 



Mandelic acid decomposes vigorously, benzaldehyde and benzoic acid 

 being obtained in considerable quantity, the benzoic acid presumably 

 resulting by oxidation of the benzaldehyde, for benzaldehyde is rapidly 

 changed to benzoic acid by the tropical sun. 



In each of two 250 cubic centimeter Ehrlenmeyer flasks 50 grams benzaldehyde 

 was placed. One flask was put in the dark and the other in sunlight for one 

 week; at the end of this time 2.2 grams and 18.5 grams of benzoic acid respectively 

 had been formed. 



It is noticeable that the tropical sunlight greatly accelerates the 

 reaction. The same effect has been noted with a very high frequency 

 electric discharge. Citric acid give off carbon dioxide, acetone being- 

 detected among the reaction products; trichlorlactic acid easily produces 

 chloral hydrate; malonic acid gives acetic acid; all of the above with 

 the evolution of carbon dioxide; phthalic and cinnamic acids are not 

 acted upon, probably because of their insolubility. 



These few experiments demonstrate the powerful catalytic action of 

 uranium salts in sunlight; a solution of a uranium salt could probably 

 be used as a chemical photometer. I consider the action probably to 

 be intimately connected with the fluorescent nature of the solutions of 

 these Salts. The observations given above are very incomplete but as 

 researches of greater economic value to the Philippine Islands are more 

 pressing, I have abandoned the work for the present. It is evident that 

 many reactions can be studied to far greater advantage in the Tropics 

 than in the Temperate Zone, so that a new field for tropical investigation 

 is opened. 



