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XXI. Analysis of the Schist that accompanies the Menilite 

 near Paris . By Professor La m p a d i u s *• 



JL he schist that accompanies the menilite near Paris was 

 formerly confounded with poUersckiefer , or polishing slate: 

 but Werner has given it the name of klebschiefer, or adhe? 

 sive slate, on account of its property of adhering strongly to 

 the tongue. After his return from JVance he gave me some 

 of it for the purpose of chemical analysis. 



Werner gives the following as its external characters : It 

 adheres strongly to the tongue— colour, pale yellowish 

 gray-- without lustre — fracture slaty in even laminae — opake-- 

 takes a slight degree of lustre by scratching — is very tender 

 — separates into, leaves spontaneously, which is one of its 

 principal characters — specific gravity under 0*2. 



It serves as a gangue to the menilite, with which it is 

 found in the hill of Menil-Montant near Paris. — The fol- 

 lowing are the results of my chemical experiments on it. 



a. Roasted for two hours in a powerful wind furnace, it 

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

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

 crucible, or in a crucible lined with charcoal : yet it had 

 become harder and less friable. That which had been roast- 

 ed in the clay crucible was rendered very attractable by the 

 magnet. 



b. Exposed to the blowpipe on charcoal and with oxygen 

 gas, it melted in a few seconds into an opake glassy bead, of 

 a blackish brown colour. 



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

 r\ot possible to melt it : but with borax a small portion was, 

 dissolved, and coloured of a blackish brown. 



These preliminary trials, and its effervescence with mu- 

 riatic acid, led me to suspect that it contained carbonic 

 acid and iron. 



d. A thousand parts of the mineral distilled in a retort 

 yielded 270 of carbon cacti. 



e. Another thousand parts dissolved in ten times their, 

 weight of muriatic acid lost 270 parts. 



* Extracted from Beytrage zur Enveilcrung dcr Chernie, 1804. 



It 



