I514.J Analysis of Aslestous Actinolile. 209 



Sulphate of magnesia 92 grains 



Muriate of magnesia 61 



Sulphate of lime 2*3 



Carbonate of magnesia 2*3 



Carbonate of lime 2*3 



All these substances are put into the water, and then a current 

 of carbonic acid gas is passed through it till the earthy salts are 

 dissolved. 



This addition of carbonic acid is requisite only when sea water is 

 prescribed internally. When it is to be used as a bath, the addition 

 of the two carbonates may be omitted. 



Article VII. 



Analysis of Aslestous Aciinolite. By Thomas Thomson. 



M.D. F.R.S. 



The mineral to I which give this name, because I consider it as 

 possessing the characters of the asbestous actinolite of Werner, 

 occurs in considerable quantity in Huel Unity, about three miles 

 east from Redruth, in Cornwall, and was shown me by the overseer 

 as a substance with the nature of which he was not acquainted. It 

 possesses the following characters : — 



The colour is greenish grey, or rather greenish blacl<, and here 

 and there it looks as if powdered with a substance of a lemon yellow 

 colour. 



It occurs in large masses, which consist entirely of a congeries 

 of capillary crystals. 



The lustre is glistening and silky. 



The fracture, on account of the smallness of the crystals, cannot 

 be determined. That of a large mass appears fibrous from the 

 capillary crystals, which, however, cross each other in every direc- 

 tion. 



For the same reason the fragments are sharp edged. 



It is opake. 



It appears soft, as it may be easily crumbled to powder between 

 the fingers ; but this is owing to the loose manner in which the 

 crystals are attached to each other; for if we try an individual crystal 

 we shall find it difficult to scratch it with the point of a knife. 



Brittle. 



Specific gravity 2-916, at the temperature of 50°. 



1. Fifty grains of this mineral, being reduced to a finejjowder, 

 were exposed to a strong red heat in a platinum crucible. The loss 

 of weight amounted to 0'S50 grain, and was ascribed to the evapo- 

 ration of moisture. 



Vol, IV. N° III. O 



