150 ON THE WORKS AND CnARACTER 



No. 1639. — A button, which is a white compound of cop- 

 per, etc. 



1. Melted on a bit of slate with saltpetre — the solution of this salt gav» 

 a yellow precipitate, with nitrate of silver. 



2. Melt»'d on the coal the metal spread ; no flowers of oxide. It was 

 very fusible ; seemed white while molted ; tbo cooled button filed was yel- 

 low like brass ; hence, perhaps, an alloy of copper and zinc or tin. 



3. It dissolved wholly in nitric acid, forming a clear blue solution ; ex- 

 haled dry, and pure water added, a small quantity of grey powder was left 

 insoluble. 



This solution poured into much water became milky, and some of this 

 milky liquor put into a watch glass with ammonia, and then nitrate of sil- 

 ver added, yielded a yellow precipitate, 



No. 1672. — Braunkohle mit Stockwerk vom Ahlberge bei 

 Mariendorf. 



In the fire it emits a copious pungent smoke, which pains the eyes greatly. 

 An incombustible residuum remains of the form and nearly size of the bit 

 of wood, which very slowly burned to a white ash. (Paris, March 2, 1820.) 



Wilh saltpetre this incontbustiblo residuum burned like anthracite. While 

 iho saltpotro was fluid it looked liko a dark green color, though not lik& 

 manganese. On fusing again this color vanished, but on sudden cooling in 

 water the blue was restored. The solution in water was not green, and did 

 not become red. 



No. 1766.— Fuller's earth. 



1. Does not lose its black color in water. 



2. Decrepitates. 



8. Melts easily into a black glass, which seems opaque. 



4. This black glass is taken up by the magnet. 



5. Adheres to the tongue. 



6. Kubbed with a little water on a bit of unglazed china it gives a yellow 

 greenish color. 



7. Found in a basalt quarry at Wilhelmshohe. 1804. 



No. 2012. — Green clay found by self near Frankfort, April 

 the — , 1805. 



1. In a moist state it is very lubric. 



2. Compressed in this state to a thin plate it is considerably hard. 



8. In the Are hardens and melts to a black glass ; is not very fusible,, 

 and shows no inflation. 



4. fcjf^ems to dissolve in borax without much diiflculty, and colors it very 

 green. If a great quantity of the clay is put to the borax, a black bead is 

 obtained. 



5. I found it adhering to (coating one side of) a mass of lava lately 

 extracted from the earth. It had probably formed in a fissure of the lava 

 stratum. 



6. Strongly heated on coal it became black, and the edges melted to a 

 black glass. In this state it was not drawn on by the horse-shoe magnet ; 

 but reduced to powder, on a brass plate, some of the powder was taken 

 up. 



7. Sulphate of soda and iron did not dissolve it, but the bead became 

 slightly milky on cooling. 



8. Put into water it falls into lumps like curds, but which pressed with 

 the fingers, reduce to a powder. 



