<X5 



Its component 

 parts. 



ON ST6NY AND METALllNE SU»$TANC£$ 



1 heated with potafb, until they were again capable of bein£ 

 taken up by the fame acid. The folution fo made, was (lowly 

 evaporated ; and, as very nearly every thing was depofited 

 during the evaporation, I conclude all was filica. The pro- 

 portions refulting from this tingle analyfis, without the weight 

 of fulphur contained in the pyrites irregularly difleminated 

 through the whole/ were, 



Silica - - - '70 



Magnefia - - - 34 



Oxide of iron 52 



Oxide of nickel - - - 3 



Component 

 parts. 



The ttont from 

 Bohemia. 



159. 



The ftone from 

 Yorkfhire* 



EXAMINATION OF THE, STONE FROM YORK- 

 SHIRE. 



The mechanical feparation of the fubftances in this ftone 

 being as difficult as in the preceding cafe, I was neceflarily 

 fatisfied with iubmilting it to the fame treatment. I collected 

 however, 34 grains of malleable particles ; which, by the 

 procefs already more than once mentioned, left 4 grains of 

 earthy matter ; and, by yielding 37f of oxide of iron, indi- 

 cated about 4 grains of nickel. 



1.50 grains of the earthy part of the ftone were, by analyfis, 

 refolved into, 



Silica ... 75 



Magnefia • * - -37 



Oxide of iron r - - 48 



Oxide of nickel 2 



162. 



EXAMINATION OF THE STONE FROM 

 BOHEMIA. 



The probability of never being able to obtain another fpe- 

 cimen of the very remarkable fragment of this fubftance, did 

 not allow me to trefpafs more on theliberality of Mr. Greville, 

 than to detach a fmall portion. I found it of fimilar competi- 

 tion to that of the three preceding ltones ; and the Count de 

 Bourndh has already (hewn the proportionate quantity of the 

 attractable metal to be very confiderable. 16f- grains, Mt 2f 



of 



