ELECTRO NITRURETS. 247 



brought out by the action of the nascent anion ; probably 

 silver, formed by voltaic precipitation, would be found the 

 most advantageous. I transmit with this paper some speci- 

 mens of the prints of the etched plates, and of electrotypes 

 taken from them ; and in conclusion would call attention to 

 the remarkable instance which these offer of the effects of the 

 imponderable upon the ponderable ; thus, instead of a plate 

 being inscribed, as ' Drawn by Landseer, and engraved by 

 Cousins/ it would be ' Drawn by Light, and engraved by 

 Electricity.' 



[With this communication were sent plates etched by the 

 process detailed in the text ; electrotype copies from the 

 same ; and a considerable number of prints obtained from the 

 former, SEC. ELECT. Soc.] 



Postscript by the Author, Nov. i. Few. of the readers of the 

 ' Philosophical Magazine ' will have an opportunity of seeing 

 any specimens of the process ; and as the etching is not deep 

 enough to produce impressions sufficient to accompany the 

 paper, I may give an idea of them by saying that in the print 

 of a portrait which I have now before me the whole expres- 

 sion of the features is distinct, the pupil of the eye and the 

 speck of light upon it clearly defined, the gloss of the hair and 

 of the satin stock very accurate. The microscopic details alone 

 appear incapable of transference to paper ; but these, as stated 

 above, being absolutely perfect upon the etched plate, I had 

 intended to have directed some experiments to the substitu- 

 tion of more delicate materials than paper and printing-ink 

 for receiving the impressions ; incessant occupations have pre- 

 vented me, and will, I fear, for some time. 



I would suggest the employment of hyposulphite of soda 

 instead of ammonia to remove the oxychloride. 



ON SOME ELECTRO NITRURETS. 



Proceedings of the Royal Society, Feb. 4, 1841. 



THE author states that he has made many attempts to render 

 permanent the ammoniacal amalgam, and that he has suc- 

 ceeded in freezing it by means of solid carbonic acid, during 



