114 [June, 



or whether it is peculiar to that from California, I treated some from the Oural 

 Mountains in the same manner, and found that most, but not all of the lead- 

 colored scales are oxydized and assume yellow, orange and blue colors. This 

 reaction seems therefore to be an important one to distinguish Sisserskite from 

 Newjanskite. It is very likely, too, that we find in nature but two combinations 

 of Iridium and Osmium, Ir Os and Ir O34 and that Ir O33 is Ir Os-i mixed with 

 some Ir Os, as it is very difficult to distinguish their color. 



On Strontiano-ccdcite^ a New Mineral. 

 By Dr. F. A. Genth. 



Primitive form an obtuse rhombohedron (as it seems to show cleavage parallel 

 to the planes of a rhombohedron, similar to that of calcite) ; the secondary forms 

 which I observed were the second acute rhombohedron (analogous to that of 

 calcite of 65 50') and its corresponding scalene-dodecahedron. (Crystals micros- 

 copic and not very distinct ; in globular masses formed by an aggregate of rhom- 

 bohedrons, every globule terminating in the above-mentioned acute rhombohe- 

 dron. Fracture uneven. H. =^ 3.5. Sp. gr. == ? 



Colorless and transparent at the points of the aggregations, which are white 

 and translucent. The colorless crystals have a vitreous, the white ones a some- 

 what pearly lustre. 



When heated before the blowpipe it gives out a brilliant light, imparts to the 

 flame a slight crimson color, and is rendered caustic. Easily soluble in acids 

 with disengagement of carbonic acid. The solution gives a white precipitate 

 with sulphate of lime, but not with sulphate of strontia; it therefore contains 

 strontia. After, (in another quantity of the solution,) strontia was precipitated 

 with sulphate of potash, the addition of oxalate of ammonia produced a precipi- 

 tate of oxalate of lime. 



The quantities I had at my disposal were too small to admit of a quantitative 

 analysis, but I presume from the quantities, precipitated with sulphate of potash 

 and oxalate of ammonia, that lime and strontia are contained in Strontiano-calcite 

 in about equal proportions. 



The specimen was presented to me by William Wagner, Esq., who collected 

 it in the neighborhood of Girgenti in Sicily, where it, according to his statement, 

 is of rare occurrence and associated with celestine and sulphur. 



In the chemico-mineralogical system it is to be placed between Dufrenoy's 

 Dreelite and Plumbocalcite. 



Of the carbonates which have isomorphous bases, of carbonate of lime only, 

 two forms, rhombohedron and rhombic prism, have been observed; of carbonate 

 of lead, strontia and baryta, only the rhombic form is known; but when in com- 

 bination with carbonate of lime, they all likewise crystallize in the rhombohe- 

 drical form, thus forming Plumbo-calcite, Strontiano-calcite and Dreelite. It is 

 very likely, that we one of these days will meet with rhombohedrical forms of 

 the pure carbonates of lead, strontia and baryta. 



The Committee on a paper by Messrs. Audubon and Bacbman, read 

 this evening by special permission, describing a new species of North 

 American Fox, reported in favor of publication : 



Descri2)tio7i of a new North American Fox. Genjcs Yidpes^ Cuv. 

 By Audubon and Bachman. 



VuLPES Utah. 



V. c(7?"/?orc ,j?-;-wc//o?T, pilis velleris longioribus nee non gracilioribus quam in 

 V. fulvo, Cauda magna cylindracea. 



Specijic characters. Larger than Vulpes fulvis ; fur longer aad finer than in 

 that species; taillarge and cylindrical. 



