902 PROCEEDINGS OF THE SOCIETY. 



volved a study of optics as well as of geology. There was an idea 

 that such observations could be carried out better elsewhere than in 

 this country, where they first originated ; but he thought that, with 

 the aid of Mr. Beck's improvements, there would be no difficulty in 

 showing that we were able to investigate the subject, at least as well 

 as could be done anywhere else. 



Mr. Crisp exhibited and described (1) Gundlach's College Micro- 

 scope (see p. 670) ; (2) Boecker's Air-Pump Microscope ; (3) The 

 Bausch and Lomb Optical Company's Immersion Illuminator (see 

 p. 688) (the latter not, however, being 1-52 N.A. as marked, but 

 about 1 • 20 N.A.) ; (4) Thomas' Vivarium (see p. 688) ; and (5) a 

 new achromatic spherical pocket lens, by Gundlach (" Globe lens "), 

 which consisted of a sphere of crown glass enclosed in an outer sphere 

 of flint glass. 



Mr. Ingpen described a method of rapidly attaching objectives to 

 the nose-pieces of Microscopes which had been devised by Mr. E. M. 

 Nelson, the idea having been suggested to him by the method em- 

 ployed by the French for fixing the head-pieces of ordnance (see 

 p. 858). 



Dr. Ondaatje, of Ceylon, was introduced to the meeting by the 

 President, and exhibited and described a number of specimens of 

 Echinoderms, Gorgonidse, Algas, &c, which he offered to the Fellows 

 for mounting. 



The President, in thanking Dr. Ondaatje for his communication, 

 said that a small specimen of Echinus was especially curious, as it 

 seemed to him it did not consist of the original carbonate of lime of 

 the creature, but looked more like crystallized calcite, as if it had 

 been concreted in some way. 



Mr. E. W. Burgess's letter was read, accompanying specimens of 

 diatoms from the Island of Lewis (see p. 665). 



Mr. Crisp said it would be in the recollection of the Fellows that, 

 at the April meeting of the Society (see p. 440), a note by Drs. Loew 

 and Bokorny was read, as to the chemical difference between living 

 and dead protoplasm, and that some remarks were made by Mr. 

 Stewart as to the possibility of some of the effects being due to the 

 remains of the citric acid used in killing the protoplasm. Dr. Loew 

 had since written a note in reply to the criticisms, which was then 

 read as follows : — 



" I learn from the June number of your highly-esteemed journal 

 that the discovery of a chemical difference between living and dead 

 protoplasm by myself and Bokorny has given rise to some discussion 

 in the Society. Mr. Stewart has expressed some doubts in regard to 

 our statement, believing that some residual citric acid (which we had 

 applied in one case of killing the cells) might have been the cause 

 that no silver was reduced. 



