238 HISTORY OP GOLD. 



principle, as its etymology would imply : azotic is not tlie only 

 gas which takes away life ; and purified charcoal does not form 

 carbon, as Lavoisier supposed. But the facts on which these 

 theories have been raised will reraajri, when the theories shall 

 have passed away ; and of these, the discoveries of Scheele and 

 Priestley exceed in ingenuity, diversity, and number, those of 

 M. Lavoisier and all his ass' dates ; and for originality, preci- 

 sion, and importance, what have they to produce at all com- 

 parable to the discoveries of Cavendish and Black. What- 

 ever may be the fate of other republics, it is devoutly to be 

 wished that that of lettere and of science may for ever stand ; 

 and when its rights are thus openly invaded, it cannot, surely, 

 be thought unbecoming in us, the countrymen of Bacon, Boyle, 

 and Newton, to stand forward in its defence, lest the shades of 

 those immortal names rise up in judgment against us ! 

 I am, Sir, 



Your obedient servant, 



E. D. 



XT. 



Tacts towards forming a History of Gold, By Vrofcssot 

 Proust*. 



To 



Oxigen reqiii- JL O ascertain the quantity of oxigen which gold requires 



f'.^,*^**^*l^'^^,j^^" for its solution in acids, is a point essential to be determined 

 •ility of gold, , '1 



in the history of this metal, and I found it attended with more 



diflficulty than I had expected. 



800 p. muriatic gix hundred grains of muratic acid at 12° of Baume's hyr 



nitri'c^dissolve Urometer, and 200 of nitric acid at 40", dissolved by the assis- 



1S7 of goid, tance of heat 144 grains of gold. Having added 200 grains 



of muriatic acid to the solution, it .took u^ 43 grains more of 



gold; consequently 1000 grains of aqua regia, made of four 



parts of muriatic acid and one of nitric, of the strength respecr 



tively indicated by the gravities noted above, are capable of 



The muriatic, dissolving 187 grains of gold. 'llie nitric acid being of no use 



vent^^should ^^"^^ but for the oxidation of the muriatic, it is evident, that 



predominate, 



* Translated from the Journal de Physique, Feb. 1806, vol. 

 Ixii. p. 131. 



The 



