The London, Edinburgh and Dublin philosophical magazine and journal of science . y the BaronSartorius v. Waltershausen in a paper presented to the Royal Societyof Gottingen on the 1st of August of the same year. They foundindependently that the adamantine boron of Wohler and Deville, con-taining a variable and not inconsiderable amount of aluminium andcarbon, considered by Sella as possibly a definite compound of boronwith aluminium and carbon with a mechanical mixture of pure boron,crystallizes in forms belonging to the pyramidal system. Boron containing 2*4 per cent, of carbon, the boro semp
The London, Edinburgh and Dublin philosophical magazine and journal of science . y the BaronSartorius v. Waltershausen in a paper presented to the Royal Societyof Gottingen on the 1st of August of the same year. They foundindependently that the adamantine boron of Wohler and Deville, con-taining a variable and not inconsiderable amount of aluminium andcarbon, considered by Sella as possibly a definite compound of boronwith aluminium and carbon with a mechanical mixture of pure boron,crystallizes in forms belonging to the pyramidal system. Boron containing 2*4 per cent, of carbon, the boro semplice ofSella, is described by him as occurring in crystals, the faces ofwhich are not so perfect as to admit of a very accurate determina-tion of the angles they make with one another. The angles approx-imate to some of the angles of crystals of the cubic system, but theaspect of the crystals, which are usually twins, leads to the supposi- 398 Royal Society. tion that they belong to the oblique system, and that the angle be-tween the oblique axes differs but little from 90°.. The forms observed by Sella, considered as belonging to theoblique system, are :— £10 0, eOOl, c013, m 0 2 3, £ 1 0 1,_ rc 5 04,_p 5 0 8, ? 2 0 3,/201, A110, t-2 10, g 1 1 1, a 1 1 2, d 2 1 1, Z2 12. Of these, I have since reobserved all, with the exception of «, d,I, and perhaps p, the corresponding reflexion being too faint toenable me to affirm the existence of that face in the crystals I exa-mined. I have also observed the following forms in which the dis-tribution of the faces is in most cases, probably in all, the same as inthe prismatic system, or as if the oblique form hkl were always ac-companied by the oblique form hkl:w30 1, wl0 4, v40 3, #30 5, s22 3, £33 2, *22 1. On the same supposition regarding the distribution of the faces,the annexed figure represents an octant of the sphere of projection,the poles of some of the faces not wanted for comparison with thoseof graphitoidal boron being
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Keywords: ., bookcentury1800, bookdecade1840, bookidlondon, booksubjectscience
