( 167 ) 

 PEOCEEDINGS OF THE SOCIETY. 



Meeting of 10th December, 1884, at King's College, Strand, W.C, 

 THE President (the Rev. W. H. Dallinger, F.E.S.) in the 

 Chair. 



The Minutes of the meeting of 12th November last were read and 

 confirmed, and were signed by the President. 



The List of Donations (exclusive of exchanges and reprints) 

 received since the last meeting was submitted, and the thanks of the 

 Society given to the donors. 



From 

 New Polarizing Prism Mr. C. D. Ahrens. 



Mr. J. Mayall, Jun., described Dr. J. D. Cox's Microscope, ex- 

 hibited by Mr. Crisp, and manufactured by the Bausch and Lomb 

 Optical Co. It was in general design a modification of Wenham's radial 

 Microscope, the principal point being that the inclining motion was 

 obtained by using one sector only, carrying the optical body as in 

 Wale's form. It was fitted with a Zentmayer swinging siibstage and 

 a second swinging tail-piece carried the mirror ; also Bausch and 

 Lomb's frictionless fiine adjustment. It had the perfection of balance 

 of the " Wale " form, and was so steady that he should expect it to 

 be very suitable for photomicrography. (See Vol. IV., 1884, p. 279.) 



Mr. Mayall also exhibited a modified form of the Wenham single- 

 plate mechanical stage which he had designed. It had occurred to 

 him that in consequence of the flexure of the upper plate the original 

 form was hardly sufficiently firm for much of the work required of a 

 modern Microscope, and he had therefore devised a frame to carry the 

 slide, thus getting rid of the plate entirely, the slide therefore lying 

 on the rotating plate of the stage as in using the " friction " stage. 

 For ordinary purposes the old form was very convenient, but for 

 very delicate work with the highest powers, and especially when the 

 vertical illuminator was employed, the new one would, he considered, 

 be found the more advantageous. {Supra, p. 122.) 



Mr. Crisp exhibited and described Dr. E. H. Ward's last modifi- 

 cation of eye-shade. Also the Bausch and Lomb adapter for the spot- 

 lenses of the smaller Microscopes, and Kain's mechanical finger made 

 to fit over the fine adjustment of the ordinary Jackson-Lister 

 Microscope. 



Professor Bell called attention to a peculiar variety of Acineta 

 grandis S. K., found by Mr. Bolton. The figure sent by Mr. Bolton 

 was taken from Mr. W. Saville Kent's Manual, and showed the 

 difference between this and the ordinary form. 



