96 



Mr. J. D. Whitney gave the results of the chemical 

 examination of three minerals, described as new species, by 

 Prof. C. U. Shepard, (Am. Jour, of Science, New Series, 

 Vol. 2, p. 249,) namely, Arkansite, Ozarkite, and Schorlo- 

 mite. Th^se minerals are all from the same locality, in 

 Arkansas. 



The first, Arkansite, which Prof. Shepard supposed^ lo be a 

 niobate of yttria and thorina, is titanic acid, with a little iron, 

 crystallized in the form of Brookite, and having the specific 

 gravity of that variety of titanic acid, while it has, at the same 

 time, the opacity and color of nigrine, a variety of rutile. 

 Ozarkite is a zeolitic mineral, a silicate of alumina and lime, 

 with a little soda. It is probably scolezite. Among the speci- 

 mens of the third mineral, schorlomite, there appear to be at 

 least two distinct substances. One is colophonite, or lime-iron 

 garnet, which occurs both massive and crystallized ; the other is 

 a substance considerably resembling black garnet in external 

 characters, but which proved, on chemical examination, to be a 

 new titaniferous silicate. As this new mineral, however, differed 

 so widely in chemical composition, and in certain important 

 chemical characters, from Prof. Shepard's schorlomite, Mr. 

 Whitney had given it a new and more appropriate name, and 

 the name of schorlomite can be dropped till the real " hydrous 

 silicate of yttria, thorina, and oxide of iron" shall be found. The 

 name given to this new mineral is Ferrotitanite, in allusion to 

 its analogy with titanile or sphene, and to its containing iron in 

 addition to the elements of sphene. 



Its chemical composition may be represented by the formula 



(Ca3 Si + Fe Si) -f- Cafi^, 



which agrees very nearly with the results of the analyses of 

 this mineral. For particulars of the examination of these min- 

 erals, see the Society's Journal, Vol. VI., No. 1. 



Dr. Bacon exhibited eighty mineralogical specimens pre- 

 sented to the society by Mr. Alger. About a year since, 

 Mr. A. offered the society the selection of four hundred 

 specimens from his private collection. At that time eighty 



