153 



ADalfsis of 

 hjalite. 



Component 

 parts. 



ANALYSIS OF HYALITE. 



which I observed also in the common kind growing near it: 

 I have therefore endeavoured to increase it by other means, 

 which may be done to any extent, but being now particu- 

 larly engaged, the means I employ must be a subject of 

 future communication. 



I am, with great respect. 

 Dear Sir, 

 Yours very truly. 



WILLIAM SALISBURY. 



Botanic Garden, Brompfon, 

 Nov, 16, 1809s „ 



XIV. 



Note on the Analysis of Hyalite : by Mr. Bucholz' 



n 



.AVING experienced a loss of 8 per cent in my ana- 

 lysis of the hyalite, published in Gehlen's Journal for 1806, 

 vol. I, p. 202, and not knowing to what to ascribe it, I was 

 much pleased at receiving in the autumn of 1807 a suffi- 

 cient quantity, to verify my former experiments. Suspect- 

 ing that this loss was owing to water, I put 75 grs of hyalite, 

 broken into small pieces, in a Hessian crucible, and kept 

 them at a white heat for half an hour. The fragments be- 

 came myiddy and friable, and had lost 4*75 grs. As I have 

 every reason to believe, that this loss is owing entirely to 

 water, it follows, that 100 parts of hyalite give 



Silex -92. 



Water 6-3 



Some flocks of alumine and loss.* 1-6 ^ 



Hvdrites of 

 silex. 



Specific gra> 

 mty. 



100. 

 Hyalite then approaches to the noble opal, which con- 

 tains 0-1 of water, according to Klaproth ; and still nearer 

 to the common opal, which contains 0*05. According to 

 the same chemist, all these stones must be true hydrates of 

 silex. The specific gravity of this stone, taken by Mr. 

 Kopp, is 8'15 [most probably a misprint for 2'15. C] 



* A»n. deChim. vol LXXIII, p. 328. 



SCIENTIFIC 



