308 Gravity of Tung fien.+Fluat of Argil. 
difeafe, which is very common and exceedingly fatal to the 
cheftnut-tree, begins to make any progrefs, and to excavate 
the trunk, they collect heath and other vegetables, and fet 
fire to them in the cavity, till the whole furface is completely 
charred. It happens very rarely that the tree perifhes by this 
operation, and it is always found that this remedy fufpends 
+ the effect of the caries. It is praétifed with the fame*fuccefs 
on the white oak, By comparing the effects of the cautery 
on the human body, in analogous cafes of degeneration, we 
perceive a new fimilarity between difeafes which affeét the 
living organifed beings of the two kingdoms, and between 
the remedies by which they may be checked. . 
ON THE GRAVITY OF TUNGSTEN. 
The difficulty of bringing tungften to complete fufion has 
hitherto prevented the {pecific gravity of this new metal from 
being with certainty determined. Some fixed it at 17°6, ac- 
cording to the experiments of the brothers d’Elhuyar; but 
many could not believe it to be fo confiderable. C. Guyton 
lately obtained a well-formed button, of the weight of 25 
grammes, in a three-blaft-furnace, where the intenfity of the 
fire may be carried to about 185° of Wedgewood: but this 
button having broken by the preffure of the vice, into which 
it was put in order to be fawn, there was dilcovered at its centre 
a part not agglutinated, which, by expofure to the air, {peedily 
affumed a purple colour, fimilar to that which the beft fufed 
tungtien, of fuch a degree of hardnefs as to render a file bril- 
liant, exhibits on its furface. It refults, from thefe experi- 
nients, that the {pecific gravity of the fufed portion, feparated 
from that which was only fufed imperfectly, was 8°3406 ; 
that the infufibility and brittlenefs of this metal Jeave no 
other hopes of applying it to the arts, though there are abun-. 
dant mines of it in France, but by nuxing it with other me- 
tals, or by the property difcovered in its: oxyds of yielding 
fixed colours, and, fixing vegetable colours. 
FLUAT OF ARGIL. 
C. Vauquelin has received from, Denmark a white lamel- 
lated mineral brought-from Greenland, which proves to be 
5 fluat 
a a ee 
a a a os Foe 
a ee ee a ee ee ee ee ee ee 
