1815.] in ike Physical Sciences. 43 



3. My analysis of asbestous actinolite {Annals of Philosaphjy 

 iv. 209,) gives a great number of constituents, and on that account 

 is not very satisfactory. I do not mean to say that the numbers 

 given are inaccurate ; for the experiments were carefully made, and 

 most of them repeated three times ; but they lead to the suspicion 

 that the specimen was contaminated with foreign bodies ; yet to the 

 eye it was pure, and consisted entirely of a congeries of crystals. I 

 found the mineral composed as follows : — 



Silica 33*4 



Alumina 28*2 



Lime 1*046 



Magnesia 0*6 



Oxide of iron 17*15 



manganese 7*2 



Tungstic acid ? 3*84 



Copper 1 '0 



Soda 3-8 



Moisture VJ 



Loss 2-064 



100-000 



4. Green Granular ylctinolite. — This is a mineral which occurs 

 at Teinach, in the Pacher-Alps, near Marburg, in amorphous 

 pieces, where it constitutes a rock with grey and red quartz. It has 

 been confounded with smaragdite or dialiage ; but Werner has 

 lately separated it from this mineral. The following, according to 

 Karsten, are the distinguishing characters of the two species : — 



Green Smaragdite, Green Granular Actinolite. 



Lustre, pearly. Lustre, glassy. 



Fracture foliated, cleavage single. Foliated, cleavage double. 



Cross fracture uneven. Cross fracture splintery. 



Soft. Semiiiard. 



Sectile. Brittle. 



Klaproth found the specific gravity of green granular actinolite 

 3-250. It was composed of the following constituents : — 



Silica 56 



Magnesia 18*5 



Lime 15'5 



Alumina 3'25 



Oxide of iron 4-75 



chromium 1- 



manganese, a trace. 



Loss 1 • 



100-00 



