ReporU and Proceedings — Mineralogical Society. 139 



were extracted from the beach. In 1903 the beach was but a little 

 over 8 feet thick in the exposed parts, but the platform of chalk was 

 14 feet thick. The upper portions of the beach, which were the least 

 consolidated, had fallen away in such a manner as to leave cave-like 

 gaps beneatli the rubble. The number of red sandstone blocks which 

 lay on the modern beach was remarkable, forty such blocks being 

 counted in a space of 50 yards square. In 1906 the raised beach had 

 increased from 15 to 20 feet; farther west, however, tlie thickness 

 was not so great. In 1908 there were 17 feet of chalk, 12 feet of 

 beach. It is noteworthy that as the degradation of the cliff proceeds, 

 the material is rapidly carried away by the sea. No talus remains for 

 any length of time, and if the material is to be prevented from 

 disappearing into deep water, some such contrivance as chain-cable 

 groynes seems to be demanded, fixed somewhere between low and high 

 tide-marks. The only organic remains observed in tlie cliffs were 

 some fragments of shells, found at the top of the raised beach. 



At a Special General Meeting held at 7.45 p.m. befoi'e the Ordinary 

 Meeting, the following resolution was proposed by Dr. A. Smith 

 Woodward, F.R.S., and seconded by Dr. 11. D. Roberts: — 



" That it is desirable, under the existing- Charter, to admit Women to candidature 

 for the Fellowship of the Society, on the same terms as men." 



A ballot having been asked for, the resolution was rejected by 

 50 votes to 40. 



II. — Mineralogical Society. 



Tuesday, January 26.— Dr. A. E. H. Tutton, F.R.S., Vice-President, 



in the Chair. 



(1) On the identity of poonahlite with mesolite ; by Dr. H. L. 

 Bowman. Small colourless prisms, associated with stilbite and pale- 

 green apopliyllite from Poonah, which appear to be identical with the 

 mineral described by H. J. Brooke in 1831 as poonahlite, are shown 

 by analysis to be mesolite having a composition corresponding to 

 a mixture of two molecules of scolecite with one of natrolite. The 

 optical characters are similar to those recently observed by Gorgay in 

 mesolite from tlie Faroe Islands. — (2) Cross-planes in twin-crystals; 

 by Dr. J. W. Evans. A twin-plane is composed of two equivalent 

 plnnes, one from each component crystal, and every line in it is com- 

 posed of two equivalent lines. A cross-plane is also composed of two 

 equivalent planes, but there are only two, four, or six lines (at right 

 angles in pairs) composed of equivalent lines. A plane of composition 

 is always a twin-plane or a cross-plane. In the former molecular 

 distances are the same in all directions in the plane ; in the latter 

 in two, four, or six directions only. — (3) Comfiarison of the refractive 

 indices of adjoining crystals in a rock slice which have their directions 

 of vibration oblique to one another ; by Dr. J. W. Evans. The nicols 

 axe placed with their directions of vibration parallel and bisecting the 

 angle 9 between the directions of the vibrations whose refractive 

 indices are to be compared. The light received from these directions 

 will (apart from interference) be proportional to cos^ -|, and that from 



