ELECTRIC LIGHT. 283 



slow), and when perfectly dry it is very hard ; place the 

 ends of the discharging rods upon this substance, about 

 two inches asunder, and take the explosion of a Leydea 

 phial. The fluid does not pass over the surface of the 

 sulphurct quietly, but strips it from the board, and dis- 

 perses it with violence in every direction, giving the ap- 

 pearance of a beautiful shower of fire. ^ 



Phosphate of lime. All the bones which I have tried Phosphate of 

 are luminous by the absorption of electric light, and the lioiQ. 

 enamel of the teeth is still more so; ivory is very phos- 

 phorescent by the explosion, and readily perforated by 

 it. The shock from a small phial will perforate from 

 nine to twelve ivory fansticks, and the spark renders 

 these thin slips of ivory transparent. Phosphoret of lime 

 gives a very minute red spark, and is but slightly phos- 

 phorescent when the explosion is made above its surface. 



But its most remarkable property is that of being in- — Isinilarama- 

 flammable by means of a very small shock passed through gmaU^shoick^'^ 

 it. As the flame is readily extinguished, a very small 

 piece of the phosphoret, about half the size of a filbert, 

 may be set on fire several times. 



I have tried many of the testacea and lithophyta, and 

 considering the facility with which all of them imbibed 

 the electric light^ I suspect it is a general property be- 

 longing to those tribes. The same may be said of all 

 extraneous fossils, which are of a calcareous nature. 



Considering how beautifully luminous calcined oyster Q^ick ^i^« *• 

 shells and belemnites are rendered by the electric explo- luminous, 

 sion, I was much surprised to find quick lime fresh from 

 the kiln rank amongst the least phosphorescent of the 

 calcareous genus. Besides the substances here individu- 

 ally specified, I have tried several of the marbles, lime- 

 stones, stalactites, and spars, all of which were phos- 

 phoric. 



Should any thing curious occur in my trials with the 

 remaining genera, I shall not fail to inform you, if you 

 think this communication worth acceptance. 



I remain your's, &c. 

 WM. SKRIMSHIRE, Jun* 



Wisbech, Oct. 16. 1806. 



Qq ^ 



