454 Mr. Henry on the Natural Hi/lory, &c. 
Steatite, or Soap-rock, contains, according to 
Sir T. Bergman, 17 of mild Magnefia in 100 
parts of that compound. 
A loofe earth, found in Silefia, and defcribed 
by Margraaf, contains * of its weight of 
Magnefia. 
Fibrous Afbeftos contains, in 100 parts, 
from 1 1 to 28, and. Coriaceous Afbeftos, 
from 11 to 26 parts of magnefian earth, 
united to aerial acid. Amianthus affords 
18, 6, Lapis Nephriticus 33, and Venetian 
Talc, an undetermined number of parts of the 
fame earth. 
Colourlefs Mica affords, on analyfis, 20 parts, 
in 100, hlue Schiftus 8, black Hornjlone 16, and 
Killas 6 parts of Magnefia. 
Magnefia is alfo contained, in fmall quantity, 
in Chryfopathium, Felt-Spar, Schoerl, and Ba- 
faltes : and Pumice-ftone yields of it, from 6 
to 15 parts in 100. 
A martial muriatic fpar, found by M. Monnety 
at St. Marie aux MineSy and, by him, named 
Pifolitesy is conftituted of 50 parts of Silex, the 
remaining parts confifting of mild Magnefia and 
Iron, the proportions of which are not dq- 
termined. * 
Such are the compounds under which mag¬ 
nefian earth is principally found ; and I havq 
* Vide Kirwan’s Elements of Mineralogy, paflim. 
colle&ed 
