ELEOTfilC LIGHT. 



101 



IV. 



On the Absorption of Electric Light bij different Bodies^ and 

 some of their Habitudes with respect to Electricity. In a 

 Letter from Mr. Wai. Skrimshire, Jun. Communicated 

 by Mr. Cutubertsox. 



Wisbech^ Jan. 14, 1807. 

 Dear Sir, 



/a.S you thought my former account of some electrical ex- phosphofcs- 

 periments on the phosphorescency of calcareous substances cence of bodies 

 worth sending to Mr. Nicholson's respectable and valuable 

 Journal, I now trouble you with a second letter, contain- 

 ing the results of other experiments, made with the same 

 view, upon the ditferent species of the remaining earths that 

 were within my reach. But I do not intend to stop here.— 

 And as I perceive the chief value of my inquiries will rest 

 upon their being a depot of numerous facts, whereon other 

 philosophers may more successfully build than my abilities 

 will enable me to do, it becomes necessary for me in this, 

 and any future communication upon the same subject, to 

 speak more in detail than I at first intended. If in this 

 state, you should still think them worth public attention, I 

 shall be glad to see them inserted in the Philosophical 

 Journal. 



Barytic Genus. 



Carbonate of barytes atTorded no spark, but was very garytic corn- 

 luminous when the shock was passed above it, though the pounds, 

 iight was of short continuance. 



Sulphate of barytes. — The several specimens of this sub- 

 stance, which were subjected to experiment, were all lumi- 

 nous by the electric shock, but were not so brilliant as tha 

 carbonates; they also differed from them in giving very good 

 sparks when placed upon the prime conductor ; except some 

 specimens, consisting of small crystals, which acting as sq 

 many points, gave out the electric fluid to the atmosphere, 

 and would not allow a spark to be taken from them. It is 

 purious, and worthy observation, that in these two barytic 

 species the facts turn out exactly the reverse of what takes 



plac* 



