H. C. Bolton—Action of Light on Uranium. 207 
The.green crystals proved to be sulphate of the pro- 
toxyd of uranium. Ebelmen confirmed Bucholz’s observation 
nor Hunt, in their valuable researches on light, notice the dis- 
coveries made up to this date. I can find no mention of in- 
vestigations on this subject, until the year 1857, when C. J. 
Burnett} published his discovery of the use of uranium salts 
In photographic printing. 
t seems strange that attempts to employ uranium were not 
made at an earlier date, when it is remembered that Bucholz’s 
discovery, in 1805, was contemporaneous with those of Sir H. 
Davy and Wedgewood, who procured the first pel 2a of 
Which we have authentic record. Burnett was quickly followed 
by Niepce de St. Victor,{ who rediscovered processes similar to 
* J. prakt. Chem., xxx, 308. + Liverpool Journ. Phot., 1857. 
$ Compt. Rend. xlvi, 449. 
