xl 



and of papers on optics, critical and scientific notices. He took an 

 active part in the Society for the Advancement of the Arts, and was for 

 several years General President of the Society. He twice presided, in 

 1845 and in 1865, over the Helvetic Society of Natural Sciences. With 

 the Prix Monthyon, received from the Academie des Sciences for electro- 

 chemical gilding, he founded a quinquennial prize to be given to the 

 author of the discovery most useful to Genevese industry, and he 

 augmented this sum by a legacy. He was a. foreign member of the 

 Prench Academy and of the Royal Society. 



