Proceedings of Learned Societies. 881 



examined microscopically, it could be seen that the replacement of 

 the carbonate of lime began by the silica appearing as minute points 

 in the centre of the interspaces and of the sclerenchyma, and not on 

 their surface. In conclusion, the influence of all the forms enume- 

 rated above in the preservation of organisms was discussed, and the 

 relation of hydrated silica to destructive forms of fossilization was 

 pointed out as being one cause of the incompleteness of the geologi- 

 cal record. 



May 11. 



Mammalian Remains near Thame. — Mr. Codrington described a 

 railway- cutting through a hill between Oxford and Thame which 

 exposed a section of certain gravel-beds, from which many Mam- 

 malian remains were collected. The hill is nearly surrounded by 

 the Thame and two small tributaries, and consists of Kimmeridge 

 clay capped by a bed of coarse gravel overlain by sandy clay. The 

 gravel consists of chalk- flints, pebbles derived from, the Lower Green- 

 sand, and fragments of mica-schist, etc., indicating a northern-drift 

 origin ; it contained many bones of Elephant, Rhinoceros, Horse, 

 Ox, and Deer, and a single phalanx of a small carnivore, but no flint 

 implements were discovered. 



Deposit at Stroud containing Flint Implements, Land and 

 Freshwater Shells, etc. — In the construction of a reservoir near 

 the summit of the hill above the town of Stroud, Mr. E. Witcbell 

 observed, about two feet from the surface, a deposit of tufa contain- 

 ing land-shells with a few freshwater bivalves ; in it he subsequently 

 discovered several flint flakes of a primitive type, and in the over- 

 lying earth a few pieces of rude pottery. The deposit is situated on 

 the spur of a hill nearly separated from the surrounding country by 

 deep valleys ; Mr. Witchell considered it to be comparatively recent, 

 and concluded that it had been formed in a pond or lake, which had 

 been caused by a landslip from the higher ground, producing a dam 

 that stopped the downflow into the valley of the water of the neigh- 

 bouring springs. 



ROYAL INSTITUTION.— May 6. 



The Properties of the New Metal Indium. — Professor Roscoe 

 gave a lecture on the characters of this metal, which has recently 

 been discovered by Reisch and Richter in the Zinc blende of Frei- 

 berg, by means of the spectroscope. Indium is distinguished by 

 having a spectrum consisting of two bright indigo-coloured lines, 

 and by its compounds tinting the colourless flame of a Bunsen 

 burner of a violet colour. 



Hitherto indium has only been obtained in very minute quantity 

 from the Freiberg blende, consequently its properties and com- 

 pounds have not been very carefully examined. It appears closely 

 to resemble zinc, with which it has hitherto always been foun d in 

 combination. It is, however, a softer metal, marking paper liko 

 lead ; it is readily soluble in hydrochloric acid, and, heated in the 



