382 Reports and Proceedings — Zoological Societ//. 



and other authorities that kaoiinization was effected by the rise of 

 solutions of carbon dioxide from among calciferous rocks receives 

 support from the occurrence of calcium sulphate in underground 

 waters and of numerous calcium compounds in mineral veins and 

 lodes. The unchanged condition of some topaziferous granite is one of 

 various indications that the action of hydrofluoric acid on rocks has 

 been low down rather sui^erficial. It, or hydrofluosilicic acid, appears 

 to have played a part in the following sequence of events in the \Vest 

 of England : — (1) Decomposition of deep-seated calcite-bearing rocks, 

 and consequent kaoiinization of neighbouring granite by evolved cai'bon 

 dioxide. (2) Local and variable dekaolinization, fluorization, and 

 tourmalinization of china-claj- rock and china stone by borated waters 

 carrj'ing dissolved fluor-spar, resulting in the formation of schorlaceous 

 rocks and greisen. (3) Last!}', supply to the metasomatized rocks of 

 tin stone and wolfram from solution, and then of silica. The author 

 concluded Avith a brief summary of facts subversive of the popular 

 notion that the kaolin of commerce is the result of subaerial action 

 upon granite. — On Schwartzembergite, and the drawing of light 

 figures, by G. F. Herbert Smith. The author described the crystals 

 occurring on three specimens in the British Museum, the locality 

 being San Rafael, Chili. They are formed of four low pyramido-faces 

 above and below, eight in all, with nearly square contour, the angle 

 from the centre averaging 20° with range 15°-25°, and simulate 

 tetragonal sj-mmetry ; steep pyramids are occasionally present also. 

 The mean refraction is 2-350. The optical characters are remarkable : 

 through each pyramid face appears in convergent light a biaxial 

 interference-figure (2E = 16°) with negative birefringence, the axial 

 plane being parallel to the edge of the contour ; but through inter- 

 mediate sectors appears another biaxial interference-figure with larger 

 angle (2E =: 33°), the axial plane being in this case radial ; the 

 number of different directions of single refraction in the crystal is, 

 however, only four. The pyramids give, with pin - hole object, 

 a continuous band of light. Since there was no well-defined image 

 from which to measure, it was necessary to draw these figures direct 

 on to a projection. The author described a camera-lucida attachment 

 for the goniometer, which would allow of the preparation of projections 

 of different sizes and of the relative variation required bj- the distortion 

 in a projection. — The chemical composition of Seligmannite, by 

 G. T. Prior. The results of two analyses show that this new mineral 

 from the Binnenthal is a sulph-arsenite of copper and lead (Pb Cu As S..) 

 corresponding to the sulph-antimonite, bournonite, with which it is 

 crystallographically similar. 



III. — Zoological Socikiy of London. — June 16t/t, 1908. Dr. Henry 

 Woodward, F.ll.S., Vice-President, in the Chair. 

 Dr. A. Smith Woodward, E.R.S., F.Z.S., exhibited photographs 

 and fragments of skin and bone of a Mammoth and a Rhinoceros 

 discovered in an ozokerite mine at Starunia, Galicia. The carcases 

 of these animals appeared to have found their way into an old marsh 

 saturated with petroleum, which had completely preserved them. 



