TRANSACTIONS 



OF THE 



cotimt Jnstitute of t 



SESSION OF 1906-1907- 



THE INFLUENCE OF RADIUM ON THE DECOMPOSITION OF 

 HYDRIODIC ACID.* H. JEKMAIN M. CREIGHTON, M. A. 

 Dalhousie University, Halifax, N. S. 



(Communicated by Dr. E. Mackay. 25th October, 1907.) 



The first mention of the influence of radiant energy of any 

 kind on chemical reactions was made by William Cruickshanks 1 , 

 who observed that hydrogen and chlorine combine under the 

 influence of light. This particular reaction has been the source 

 of many investigations, carried out by such men as Dalton 2 , 

 Draper 3 , Bunsen and Roscoe, and, very recently, Mellor 4 , Bevan 5 , 

 and Burgess and Chapman 8 . Of the numerous reactions affected 

 by light, the following are some of the more important : in- 

 fluence of light on silver salts, on the action of bromine and 

 chlorine on metallic silver, on dyed colours, on enzymes in 

 oxygen and hydrogen, on glass, on the oxidation of iodoform, 

 action of oxygen on carbon bisulphide under the influence of 

 light, the decomposition of hydrogen peroxide by light, effect of 

 light on the combination of hydrogen and bromine, and the 

 reaction between chlorine and benzene in the light. 



*Contributions from the Science Laboratories of Dalhousie University [Chemis- 

 try]. Printed in advance in present part by permission of the Council of the Institute. 



1. Nicholson's Jour., 1801, (1), 5, 202. 



2. A New System of Chem. Phil., p. 300. 



3. Phil. Mag., 1844, (iii), 25, 9 : 1845, (iii), 26, 473. 



4. Journ. Chem. Soc., 1904, 63. 



5. Proc. Camb. Phil. Soc., 1902, (ii), 264-266. 



6. Jour. Chem. Soc., 1906, 88, 1399. 



PROC. & TRANS. N. S. INST. Sci., VOL. XII. TRANS. 1. 



