ANALYSIS OF ADHESIVE SLATE. | -^ 



XIV, 



Jirtal^sis of the Schist that accompanies the Menilite near 

 Paris: by Prof, Lampadius*. 



T, 



HIS mineral was formerly confounded with pollerfchie- Adhesive anfl 

 Jer, or polishing slate : but Werner has given it the name of polishing slate 

 klebpchiefer^ or adhesive slate, on account of its property of fo^p^ig^j 

 adhering strongly to the tongue. On his return from France 

 he gave me a certain quantity, that I might subject it to 

 chemical examination. 



The following are its external characters, as given by Wer- Characters of 

 ner. It adheres strongly to the tongue. Its colour is of a° '^i-^"*"^ ^ ^^e^ 

 pal€ yellowish gray. It is without lustre. Its fracture is 

 slaty, with straight leaves. It is opake. Scratcliing gives it 

 a little lustre. It is very tender. It separates into leaves 

 Sj-wntaneouslvj which is one of its principal characters. It 

 is light, not being twice as heavy as water. 



It serves as a gangue to the uienilite, with which it is found Where found. 

 in the hill of Menil-Montant near Paris. 



The following are the results of my chemical experiments Analy.^is. 

 on it. 



a. Roasted for two hours in a very active wind furnace Cakiuedl. 

 it lost 30 per cent of its weight. Its colour became a deep 

 brown. It exhibited no signs of fusion, either in a clay ctu~ 



cible, or in a crucible lined with charcoal : yet it hivd become 

 harder, and less friable. That which had been roasted in 

 the clay crucible was rendered very attractable by the mag- 

 i^et. 



b. Before the b'owpipe on charcoal and with oxigen gas Treated wiili 



it melted in a few seconds into an opake glassy bead, of a *^^t)!owinpe 



■^ o J ■ ^ and oxigun 



blackish brown colour. gas: 



c. Exposed to the flame of the blowpipe simply, it was with borax. 

 not possible to melt it: but with bo.ax a small portion was 

 dissolved, and coloured of a blackish brown. 



These preliminary trials, and its effervescence with n)u- 

 riatic acid, led me to suspect, that it contained carbonic acid 

 and iion. 



*J'jurna!de Mines, N. lOG, p. S17. Extracted from a work pub- 

 lished by |,>rof Lampadius in ISO i under the title of Bei/trage zur Erwelte- 

 7uv(^ der Chemie, 



d. A ■ 



