page 259 note 2 The following were the papers read before the Society : 'On sartorite,' by R. H. Solly, June 16, 1914, and 'On the problem of sartorite,' by O. F. Herbert Smith, June 19, 1917.

page 259 note 3 An interesting description of the quarry, including an accotint of its history, is given by Leon Desbuissons in 'La Vallée de Binn (Valais),' Lausanne, 1909, Georges Bridel & Cie, pp. 60-67, some of the partiehlars being supplied by R. H. Solly.

page 260 note 1 Altogether upwards of twenty-five mineral species have been described from the Lengenbach quarry. Tile most interesting of them are jordanite, tennantite (binnite), and hamlinite (bowmanite), and those peculiar to the quarry, viz sartorite, seligmannite, bsumhauerite, rathite, dufrenoysite, lengenbachite, liveingite, marrite, and hatchite, which are black and opaque, and hyalophane, smithite, hutchinsonite, and trechmannite, which are transparent, the first being eolom'less and the remainder red.

page 260 note 2 Herbert Smith, G. F., On the remarkable problem presented by the crystalline development ofcalaverite. Mineralogical Magazine, 1902, vol. xiii, pp. 122-150Google Scholar.

page 260 note 3 Trechmann, C. O., Crystallography of sartorite from Binn. Mineralogical Magazine, 1907, vol. xiv, pp. 212–229 CrossRefGoogle Scholar. It is evident from the concluding paragraphs of his paper that he fully realized the uncertainty of the identity with sarterite of the crystals numbered by him 1 and 2. After pointing out that the character of even the smallest pyramidal faces permitted of exact goniometrical measurement he says—' With less confidence would I wish it to be assumed that the crystals Nos. 1 and 2 are, beyond doubt, to be considered as sartorites.

page 261 note 1 Lardy, C., Essai sur la constitution géognostique du St.-Gerhard. Denkschriften der allgemeinen Schweizerischcn Gesellschaft fur die gesammten Naturwissenschaften, 1883, vol. i, pp. 200-280Google Scholar. See p. 244: ' La dolomie de Binden renferme, en outre du Feldspath adulaire, de l'arsenic sulfuré rouge et jaune, du zinc sulfuré jaune en beaux eristaux et une substance métallique d'un gris de plomb qu'on a prétendu ètre de l'antimoine.'

page 261 note 2 Wiser, D. F., Beitrage zur mineralogischen Kenntniss des Schweitzerlandes. Neues Jahrbuch Min., 1839, pp. 406–415 Google Scholar. See p. 414.

page 261 note 3 D. F. Wiser, ibid., p. 557.

page 261 note 4 D. F. Wiser, Neues Jahrbuch Min., 1840, p. 216.

page 261 note 5 Cf. Annalen der Physik u. Chemic, 1885, vol. xciv, p. 335Google Scholar.

page 261 note 6 A. Damonr, Notice sur le sulfo-arseniure de plomb du Mont Saint-Gothard. Annales de Chimie et de Physique, 1845: 8rd series, vol. xiv, pp. 879-888. Also see l'Inst. 1845, p. 141 ; Compt. Rend. Acad. Sci. Paris, 1845, vol. xx, p. 421Google Scholar.

page 261 note 7 Sartorius von Waltershausen, W., Ein Beitrag zur näheren Kenntniss des Dolomits in den Walliser Alpen. Annalen tier Physik u. Chemic, 1855, vol. xciv, pp. 115-141Google Scholar. See also Sitzb. Akad. Wien, 1854, vol. xiv, p. 291Google Scholar.

page 262 note 1 , to break. See lee. cit., p. 126, 'seiner ausserordentlichen Sprödigkeit hailer'. The name is not very happily derived ; the first of the Greek words has much the same shades of meaning as the Latin durus, and the obvious meaning of the word scleroelase would be a substance difficult to break, which is just the opposite to what was intended.

page 262 note 2 Mineralogical Magazine, 1907, vol. xiv, p. 287.

page 263 note 1 Heusser, C., Uber den Dufrenoysit, Binnit und Adular des Binnenthales. Annalen dee Physik u. Chemie, 1856, vol. xcvii, pp. 115-129Google Scholar.

page 263 note 2 Houseer, C., loc. cit. Cf. also ibid., 1855, vol. xciv, pp. 334-386Google Scholar. 'Binnit, ein Name, dee in der Schweiz aueh bisher statt Dufrenoysit allgemein gebraucht wurde (—man wusste noch Nichtn yon zwei verachiedenen Sehwefelmetallen, sondern glaubte damit den Dufrenoysit des Hrn. Damour zu bezeiehnen—) und der ganz passend an den blsher einzigen Fundort erinnert.'

page 263 note 3 Des Cloizeaux, A. L. O., Sue lea formes cristallines de la dufrenoysite. Annales des Mines, 1855, 5th series, vol. viii, pp. 389-398Google Scholar.

page 264 note 1 Cf. G. vem Path, Annalen der Physik u. Chemie, 1864, vol. cxxii, p. 873.

page 264 note 2 Solly, R. H., Mineralogical Magazine, 1900, vol. xii, p. 283Google Scholar.

page 264 note 3 As was pointed out above (p. 262) yon Waltershausen's hypothetical species lied the composition of dufrenoysite ; no doubt some of his material was sartorite.

page 264 note 4 Throughout the present paper the authors use the term 'prism' for the striated zone the edge of which is parallel to the length of tile crystal, and the term 'dome' for the, when present, generally broad and well-developed zone running over the end of the crystal. Since, as will be seen below (p. 307), the symmetry is really monoclinic with the plane of symmetry at right angles to the length of the crystals, the terms should , if to accord with the old convention, be interchanged.

page 265 note 1 For convenience of reference the forms are lettered in accordance with the notation adopted in this paper (p. 274).

page 265 note 2 Dana, J. D., System of Mineralogy, 5th edit., 1868, p. 88 Google Scholar.

page 265 note 3 Baumhauer, H., Über den Skleroklas yon Binn, Sitzungsber. k. preuss. Akad. Wiss. Berlin, 1895, pp. 243-252Google Scholar.

page 266 note 1 Solly, R. H., Sulpharenites of lead from the Binnenthal. With analyses by H. Jackson. Mineralogical Magazine, 1900, vol. xii, pp. 282-297Google Scholar.

page 266 note 2 R. H. Solly, loc. cit., pp. 286, 287, 289.

page 267 note 1 R. H. Solly, loc. cit., p. 297.

page 267 note 2 Baumhauer, H., Eclogae geol. Helvetias, 1902, vol. vii, pp. 352-853Google Scholar.

page 267 note 3 Lewis, W. J., A large crystal of sulpharaenite of lead from the Binnenthal. Mineralogical Magazine, 1903, vol. xiii, p. xxxivGoogle Scholar.

page 267 note 4 Solly, R. H., On sartorite, anatase, galena, and other minerals from the Binnenthal. Mineralogical Magazine, 1904, vol. xiv, p. xxGoogle Scholar. Abstract in 'Nature', 1903, vol. lxix, p. 142:—'…On fine brilliant crystals of sartorite recently obtained by the author he has been able to confirm the oblique symmetry which he had previously announced, and to determine accurately the elements, β=88° 31', (100) (101) = 54° 45', (010) (111) = 69° 521/2'…' The last two angles appear, however, to have been incorrectly transcribed.

page 267 note 5 H. Baumhauer, Über die Aufeinanderfolge und die gogensoitigen Beziehungen der Krystallformen in flächenraichen Zonen. Sitzungsber. k. preuss. Akad. Wiss. Berlin, 1904, pp. 543-554. See also Eclogae geol. Helv., 1906, vol. viii, pp. 582-588Google Scholar.

page 268 note 1 Trechmann, C. O., Crystallography of sartorite from Binn. Mineralogical Magazine, 1907, vol. xiv, pp. 212-229Google Scholar. The crystals were presented by Dr. Treehmann to the British Museum in 1917, just before his death ; those numbered by him 1 and 2 are entered under 390, 3 and 4 under 391, 5 and 6 under 392, and 7 under 893 for the year 1917 in the Register of Accessions in the Mineral Department.

page 268 note 2 C. O. Trechmann, loc. cit., p. 214. This statement is incorrect. No semirevolution about any axis will bring the poles of the one crystal into coincidence with those of the other.

page 268 note 3 C. O. Treehmann, loc. cit., p. 226.

page 269 note 1 L. Desbuissons, La Vallée de Binn (Valais). Lausanne, 1909. For sartorite see pp. 104-106.

page 269 note 2 Solly, R. H., On sartorite. Mineralogical Magazine, 1914, vol. xvii, p. xxxi Google Scholar. Abstract ill ' Nature ', 1914, vol. xoiii, p. 471, ' From a goniometrical examination of 200 crystals it is contended that Dr. Trechmann's crystals, Nos. 1 and 2, belong to a species closely allied to sartorite and smithite. Many new forms for ssrtorlte were found.'

page 272 note 1 Herbert Smith, G. F., Mineralogical Magazine, 1899, vol. xii, pp. 175-182Google Scholar. It may be mentioned that in October 1906, when a convenient opportunity offered itself, the second circle was returned to Messrs. Troughton and Simms, and the vernier made adjustable, with the view of obviating the small zero correction previously necessary in the case of the azimuthal angles.

page 273 note 1 This is the face (041) of vom Hath and Baumhauer.

page 277 note 1 The angles stated to have been observed in the prism-zone were those determined from the cross-zonal relations of the pyramidal faces by means of the third circle of the three-circle goniometer. Wherever possible, three angles were thus measured of which theoretically only two were necessary ; the actual angles taken as data were~ however, those considered, having regard to the probable accuracy of the adjustment of the several origins, to accord best with the measured angles. In the case of crystals 8 and 5, a somewhat similar procedure was adopted for the dome-zone, the datum angle being based on more than one angle.

page 278 note 1 'In the column headed 'Reflections' the letters indicate the quality of the reflected imago and therefore the trustworthiness of the measured angle, viz. g good, f fair, b bad, s striated.

page 284 note 1 Loc cit., p. 226.

page 284 note 2 Loc. cit., p. 251.

page 302 note 1 Loc. cit., pp. 214, 225, 226.

page 314 note 1 See Mineralogical Magazine, 1902, vol. xiii, p. 142.