ANALYSIS OF MAGNF.SITE. ^^A 



countries in order to make knovro the effects of art on this 

 plant*. 



VII. 



Mineralogkal and. Chemical Examination qfMagnesile, the 

 „ native Magnesia of Werner : bi/ Messrs. Haberle and 



,,. .BfJCIJOiLZt. ' 



2 JL HE gpecimens employed in this description and analysis Mineralo^csJ 

 were sent by counsellor Andre of Brunii from Hrubschitz, descriptiaa- 

 •hi the lordship of Gromau, in Moravia, Those analysed by 

 -Mr. Mitchell, which led Werner to make a separate species 

 of this mineral in his system, were from the same place. 



Various inaccurate oryctognostic descriptions, which have Errours mx&. 

 been given in the different elementary works of France and "*"* wriiess 

 Crermany, lead us to wish for a fresh examination of this 

 substance. Thus Reuss and Suckow have said, that mag>. 

 nesite shines when rubbed, that it is light, and that its spe- 

 cific gravity, according to Gerhard, is 0-31: but certainly 

 Gerhard was mistaken, or spoke of some other substance. 

 Guy ton too, when he gives its specific gravity at 2*1 62, is 

 wrong ; as the late experiments of Haiiy on the same sub- 

 stance show. They who say, that this substance is difficult 

 to break, and that it adheres slightly or not at all to the 

 tongue, have fallen into a still greater errour. 



Brongniart, in his Elementary Treatise on Minerals, de- BTongmz.tZr 

 scribes this substance too slightly, or repeats the errours of 

 •thers; as for instance when he says, that it is greasy to the 

 touch. In fact he brings under the species magnesite to© 

 many minerals, which differ both in their oryctognostic and 

 chemical principles. Thus he unites the meerschaum, or 



• Foran account of the empyreumatic oil of tobacco, and its poison- 

 ous effects en the animal economy, by Mr. Brodie, see Journal, vol. 

 XXX, p. 305. 



t Ann. de Chim. vol, LXXIV, p. 65. Translated from Gehlen's 

 Journal, N* SI and 32, by Mr. Tassaert. 



plastic 



