﻿CATALYSIS BY MEANS OF URANIUM SALTS IN THE 

 SUNLIGHT. 



By Raymond Foss Bacon. 

 (From the Chemical Laboratory, Bureau of Science, Manila, P- I.) 



A few experiments were undertaken on the catalyzing effects of 

 uranium salts in sunlight in conjunction with the study of the radio- 

 activity of the waters from Taal volcano, described in the preceding paper. 

 Seekamp 1 a great many years ago demonstrated that uranium salts acted 

 as catalyzers in decomposing oxalic acid in the sunlight, but the same 

 effect was not produced in the dark, even at 100°. The products of the 

 catalysis were carbon monoxide, carbon dioxide, water and formic acid ; 

 on substituting succinic acid, Seekamp obtained propionic acid and 

 carbon dioxide. Since the discovery of radium and of its capability of 

 powerfully catalyzing many chemical actions, it becomes interesting to 

 ascertain whether the catalytic action of uranium salts in the sunlight 

 may not be due to the fact that uranium is one of the elements which 

 forms radium and whether its power of catalyzing may not in some man- 

 ner be connected with its radio-activity. As the sunlight of the Tropics 

 afforded an exceptionally favorable opportunity, the following experi- 

 ments were undertaken with the view of proving or disproving this 

 supposition. 



The apparatus consisted of a 100 cubic centimeter, graduated Ehrlenmeyer 

 flask and a eudiometer. The flask was tightly closed with a well-fitting rubber 

 stopper, through which a glass tube passed to the eudiometer. The gas was 

 collected over the water. Two or more such flasks were usually placed in the 

 sunlight simultaneously, and the time necessary to collect a certain number of 

 cubic centimeters of gas was noted. 



The fundamental experiment was instituted to give a comparison of 

 the rate at which a certain quantity of uranium salt would act as a 

 catalyser of oxalic acid, when it was compared with pitchblende contain- 

 ing the same amount of uranium, pitchblende being over five times as 

 radio-active — measured by the electrical method — as the uranium salt. 

 It would follow from this that, if radio-activity had any connection with 

 the catalytic process, the rate of gas formation with pitchblende would 

 be very much more rapid than it would be with uranium salt. 



A few experiments were first made in the apparatus with oxalic acid 

 alone, 5 grams being used in each instance, and it was found that sunlight 



1 Am. Chem. (Liebig) , (1802) 122, 113; (1865) 133,253. 

 54329 4 129 



