HORNBLENDE. 155 



Dif. Distinguished from pyroxene as stated under that | 

 species , the black variety from black tourmaline by its per- 

 fect cleavage, (tourmaline having none.,) and also by the 

 form of its crystals $ the fibrous varieties from picrosmine, 

 nemalite, and tabular spar, as stated under those species ; 

 from the fibrous zeolites by not gelatinizing, and, when 

 in limestone or serpentine, by its gangue. ^ 



Obs. Hornblende is an essential constituent of certain 

 rocks, as syenite, trap and hornblende slate. Actinolite is 

 usually found in magnesian rocks, as talc, steatite or serpen- 

 tine ; tremolite in granular limestone and dolomite fasbes- 

 tus in the above rocks and also in serpentine. Black crys- 

 tals of hornblende occur at Franconia, N. H., Chester, Mass., 

 Thomaston, Me., Willsboro', N. Y. in Orange county, N. 

 Y., and elsewhere. Pargasite occurs at Phipsburg and Par- 

 sonsfield, Me. ; glassy actinolite, in steatite or talc, at Wind- 

 ham, Readsboro', and New Fane, Vt., Middlefield and Bland- 

 ford, Mass. ; and radiated varieties at the same localites and 

 many others. Tremolite and gray hornblende occur at Ca- 

 naan, Ct., Lee, Newburgh, Mass., in Thomaston and Ray- 

 mond, Me., Lee and Grea f Barrington, Mass., Dover, Kings- 

 bridge, and in St. Lawrence county, N. Y., at Chesnut Hill, 

 Perm., at the Bare Hills, Md. Asbestus at many of the 

 above localities ; also at Milford, Conn., Brighton and Shef- 

 field, Mass., Cotton Rock and Hustis's farm, Phillipstown, 

 N. Y., near the quarantine, Richmond county, N. Y. Moun- 

 tain leather is met with at the Milford quarries, and also at 

 Brunswick, N. J. 



Uses. Asbestus is the only variety of this species of any 

 use in the arts. The fHx-like variety is sometimes wo- ; 

 ven into cloth ; it has been proposed of late to use clothes 

 of it for firemen, and patents have been taken out. Its in- 

 combustibility and slow conduction of heat, render it a com- 

 plete protection against the flames. It is often made into 

 gloves. A garment when dirty, need only be thrown into 

 the fire for a few minutes to be white again. The ancients, 

 who were acquainted with its properties, are said to have 

 used it for napkins, on account of the ease with which it 

 was cleaned. It was also the wicks of the lamps in the an- 5 

 cient temples ; and because it maintained a perpetual flame 



How does the species hornblende differ from tourmaline and other 

 minerals mentioned 1 What is said of the occurrence of hornblende 1 

 What are the uses of asbestus 1 Why was it so called ? 



