14^ New Mitallie Jcld. 



tnained at the bottom of the capfule, were waflieJ with alkohol, n blue liquor was ob- 

 tained, wliich after evaporatit^n left a greenifli blue powder, foluble in water, of an 

 acid tafte, and redduiinjj the tiii£ture of turnfol. 



The red lead ore may likewife be decompofed by muriatic acid. If the latter be diluted 

 with water, the mineralizing acid is precipitated in the form of a red powder : if it be 

 concentrated, it re-acts on the metallic acid, deprives it of part of its oxygen, and caufes 

 it to pafs to a deep green colour, while vapours of oxygenated muriatic acid are difen- 

 gaged. 



Thefe experiments are fufficient to prove that the mineralizing acid of the red lead of 

 Siberia is a new fubflance ; but as it has fome refemblance with the molybdic acid, Vau- 

 quclia has made a number of comparative experiments on their alkaline compounds, which 

 prefented very evident differences. The following are the moft remarkable : 



1. The acid of Siberian lead ore is red, when combined with potafh; the molybdate of 

 potafh is white. 



2. The molybdate of potafh affords a white precipitate with the nitrate of lead, wherea'* 

 the red lead ore is regenerated of a beautiful orange colour, rcfembling that of the native 

 ore when it is reduced to powder, 



3. The molybdate of potafh affords a white precipitate in flocks, when added to the ni- 

 tric folution of mercury. The fait formed by the fame alkali and the acid of Siberian red' 

 lead affords a precipitate of a deep cinnabar colour. 



4. The former affords a white precipitate with the folution of filver ; the latter a 

 precipitate of the molt beautiful carmine red, which changes to a purple red by expofure 

 to light. 



The foregoing experiments fufhciently prove that this new acid is metallic, and differs 

 much from the molybdic acid. It does not differ lefs from the other newly difcovered 

 metals. 



Uranium does not become acid, and cannot combine with the cauftic alkalis. 



Titanium is foluble in acids, with which it forms cryftallizablc falts, and does not com- 

 bine with the cauilic alkalis. 



Tungften becomes yellow in acids without dUfolving, and affords white cryftallizablc 

 falts with the alkalis. 



The author has not purfued this comparative examination, becaufe the properties of the 

 other metallic fubllances are fufficiently known. He promifes to continue his refearches 

 as foon as he fliall have procured more of this mineral. 



P. S. Since this memoir was read to the Inftitute, Vauquelln has reduced the mineral- 

 izing acid of the red lead ore. This metal is grey, very hard, brittle, and eafily cryftallizes 

 in fmall needles. The nitric acid acidifies it with confiderable difficulty. 



H. V. C. D. 



Farther 



