CHEMICAL SCIENCE. 



ON SOME EXPERIMENTS ON THE TRANSMUTATION OF METALS. 



The following very remarkable and suggestive paper, by Dr. J. "W. 

 Draper, of New York, is published in the Philosophical Magazine, for 

 November, 1857 : 



No one who has used a tithonomcter* can have failed to have noticed the 

 disturbing effects of minute quantities of extraneous gases, mingled with 

 chlorine, on photo-chemical induction. My attention has been directed to 

 that subject in its more general aspect; and I will ingenuously confess that I 

 have made several attempts at the transmutation of metals, on the principle 

 of compelling them, by the aid of solar light, to be disengaged from states 

 of combination in the midst of resisting or disturbing media. 



The following is a description of one of these alchemical attempts. In 

 the focus of a burning lens, twelve inches in diameter, was placed a glass 

 flask, two inches in diameter, containing nitric acid, diluted with its own 

 volume of water. Into the nitric acid were poured alternately small quan- 

 tities of a solution of nitrate of silver and of hydrochloric acid, the object 

 being to cause the chloride of silver to form in a minutely divided state, so 

 as to produce a milky liquid, into the interior of which the brilliant con- 

 vergent cone of light might pass, and the currents generated in the flask by 

 the heat, might drift all the chloride successively through the light. The 

 chloride, if otherwise exposed to the sun, merely blackens upon the surface, 

 the interior parts undergoing no change ; this difficulty I hoped, therefore, 

 to avoid. The burning glass promptly brings on a decomposition of the 

 salt, evolving on the one hand chlorine, and disengaging a metal on the 

 other. In one experiment the exposure lasted from 11 A. M. to 1 P. M. ; it 

 was, therefore, equal to a continuous mid-day sun of seventy-two hours. 

 The metal was disengaged very well. But what is it ? It cannot be silver, 

 since nitric acid has no action upon it. It burnishes in an agate mortar, but 

 its reflection is not like the reflection of silver; it is yellower. The light 

 must therefore have so transmuted the original silver as to enable it to exist 

 in the presence of nitric acid. In 1837 I published some experiments on 

 the nature of this decomposition, in the Journal of the Franklin Institute. 



Though this experiment, and several modifications of it, which I might 

 relate, fail to establish any permanent change in the metal under trial, in the 



* An arrangement for measuring the chemical action of light* 



