PROCEEDINGS OF THE SOCIETY. 95 



a spring attached to fit it on to the stage of the Microscope, and a 

 central projecting peg over which the card containing the sunk cells is 

 placed — a device which would be found very handy in the demonstra- 

 tion of seeds or any other opaque object. 



The President congratulated Mr. Finlayson on the simplicity and 

 apparent efficiency of his little device, and the thanks of the Society 

 were cordially voted to him. 



Dr. Shillington Scales was then requested to read a paper by Dr. 

 Felix Jentscb, which had been brought to the notice of the Society by 

 Mr. Ogilvy, on " The Binocular Microscope." 



Dr. Shillington Scales said that the paper he was about to read was 

 an exceedingly interesting one. Mr. Conrad Beck, who was present 

 that evening, would be good enough to give them a supplementary 

 paper to that of Dr. Jentzsch, dealing with the various types of binocular 

 Microscopes, and he and Mr. Ogilvy together had arranged this extremely 

 interesting exhibit. 



At the conclusion of Dr. Jentzsch 's paper, the President said that 

 before opening the discussion on the extremely interesting communica- 

 tion which had just been read, he would ask Mr. Conrad Beck to give 

 his paper on " The Binocular Microscopes of the Past, and a new form 

 of the Instrument." 



(Before Mr. Beck had finished his paper and demonstration, the 

 President was obliged to leave on account of the lateness of the hour, 

 and the Chair was then taken by Mr. Barnard.) 



Mr. Rheinberg opened the discussion by saying that he had been 

 exceedingly interested in hearing the admirable papers just read. Dr. 

 Jentzsch's paper, he thought, had been splendidly worked out in every 

 way. 



There was one little point to which his particular attention had been 

 drawn, and that was that this Microscope would actually seem to do 

 even more than Dr. Jentzsch claimed for it, inasmuch as although, 

 according to all the canons and laws of optics, one could not obtain 

 stereoscopic effects with it with high powers, yet on another occasion 

 afforded him by Mr. Ogilvy he had certainly seen preparations under 

 this Microscope which undoubtedly appeared to him (and he thought 

 also to others) to be stereoscopic. How this could occur was a point of 

 great interest. 



One thing on which he would like to remark, pertained to one of the 

 points to which Mr. Beck drew attention, and that was as regarded the 

 parallelism of the two eye-pieces. He was not at all sure that despite 

 the parallelism of the eye-pieces, the eyes in viewing the Microscope 

 image at an apparent distance of 8 or 10 inches did not unconsciously 

 converge, and it occurred to him, though he only threw out the sugges- 

 tion with great diffidence, that it was just possible that this led to slight 

 alterations in position of the image details on the retina of one eye as 

 compared with their position on the retina of the other eye, which might 

 lead to something in the nature of a stereoscopic effect. 



In this connexion one had only to remember that as had been proved 

 convincingly by Abbe many years ago, stereoscopic effects with the 



