OBITUARY NOTICES. XIX 



spinel occurs in many localities, the most interesting coming from 

 Hindostan. The corundum crystals are from half an inch to two 

 inches across. Many of them are completely altered, and most of 

 them show that the alteration began at the surface and penetrated 

 irregularly the crystals toward the centre, leaving frequently a 

 nucleus of brownish-gray cleavable corundum. Beauxite, an 

 aluminum hydrate mixed with ferric hydrate and a hydrous 

 aluminum silicate, and enclosing grains of corundum, occurs 

 abundantly in the south of France. T. S. Hunt regarded the 

 corundum as having been produced from the beauxite by loss of its 

 water ; but Dr. Genth held the opposite view and maintained that 

 the beauxite has resulted from the hydration of the corundum. 

 Zoisite had been observed in the Urals by Gustav Rose as an asso- 

 ciate of corundum. The best locality for it in this country, how- 

 ever, is at the Cullakenee mine, where it occurs sometimes in 

 crystals, but generally in compact and columnar easily cleavable 

 masses, from grayish to greenish and brownish-white in color, 

 many of the specimens showing distinctly that it is the result of 

 the alteration of corundum, the pink corundum being often sur- 

 rounded by a thin coating of a white zoisite. Tourmaline is asso- 

 ciated with corundum at most of the localities above given. At 

 Unionville, Pa., black tourmaline occurs in irregular masses of 

 different sizes, in the corundum itself as well as in the masses 

 resulting from its alteration. Dr. Isaac Lea mentions the occur- 

 rence of a crystal of transparent green tourmaline passing through 

 the middle of a prism of diaspore, the whole enveloped by lamel- 

 lar crystals of pearly emeryllite. At the Culsagee mine there are 

 masses of black tourmaline containing crystals of white and yellow- 

 ish-white corundum disseminated through them, the particles of 

 tourmaline crystals being intermixed with the corundum crystals 

 and vice versa. Fibrolite has been long known to accompany 

 corundum both in Europe and Asia. The variety used by the 

 Celts in the stone age was obtained in the neighborhood of Chavag- 

 nac and Ourouze, in France, where it is associated with mica, 

 cyanite and red and blue corundum. At Norwich, Conn., the 

 small crystals of sapphire are completely surrounded by fibrolite. 

 Cyanite is a very common associate of corundum, rolled masses 

 of it occurring in Litchfield and Washington, Conn., containing 

 corundum and diaspore. An interesting specimen from Newton, 

 Conn., received from G. J. Brush, consists of irregularly arranged 



