1820.] Svientific Intelligence. Q§ 



and little soluble in water and alcohol. It is capable of with., 

 standing a moderate heat. It forms with acids regular salts, and 

 is capable of neutralizing a considerable proportion of acid. 

 Sulphate of atropia is composed of 



Sulphuric acid 36-52 



Atropia 38-93 



Water 24-55 



100-00 



When atropia and potash are mixed together and exposed to a- 

 red heat, the ashes, when mixed with muriate of iron, strike a 

 lively red colour. 



Hyoscyama, or the alkali extracted from the hyoscyannis niger, 

 is not easily altered in a high temperature even when heated to 

 redness with charcoal. It crystallizes in long prisms, and when 

 saturated with sulphuric acid, and especially with nitric acid, 

 forms very chai'acteristic salts. 



The examination of the alkaline constituents of narcotic plants 

 d'enaands great circumspection, because in them the whole 

 poisonous properties of the plant are concentrated. The vapour 

 is paiticularly prejudicial to the eyes. The smallest morsel put 

 upon the tongue is particularly dangerous. 



VI. Analysis of Meionite. By Professor Leopold Gmelin, of 



Heidelberg. 



The specimen of meionite subjected to experiment was from 

 Vesuvius. Though considerable pains were taken to select pure 

 crystals, it was impossible to free them entirely from leucite, 

 carbonate of lime, and a white matter, with which many of thenii 

 were encrusted. The specific gravity of the specimens examined 

 was 2-650, which approaches nearly to 2-612, the specific gravity 

 found by Mohs. Though Lelievre affirms that this mineral 

 melts easily into a vesicular white glass, and though this state- 

 ment has been copied into most mineralogical books, Gmelin 

 was unable to fuse it before the blow-pipe, or even to soften the 

 edges of the particles exposed to heat. The constituents of this 

 mineral, as determined by analysis, are as follows : 



Silica ......... 40-8 



Alumina 30-6 



Lime 22-1 



Soda with some lithia 2-4 



Oxide of iron 1-0 



Carbonic acid and loss 3-1 



100-0 



The presence of lithia was inferred from the violet colour 

 which the platinum crucible acquired. This analysis shows a» 



