PROCEEDINGS OF THE SOCIETY. 
833 
dition in which it was received, but was first put on the lathe and all 
the lens cells unscrewed and separately examined, which was the usual 
course adopted when an objective was returned for inspection. In setting 
the objective up again the foreman intrusted with the task would, no 
doubt, screw the lens cells together again exactly as they were originally 
when the objective was first despatched from Jena, and it was in that 
condition when Dr. Czapski tested it and reported that the visual and 
actinic foci were coincident, which was subsequently confirmed by the 
second photographic trials made with it in London. Mr. Mayall read 
portions of the correspondence he had had with Dr. Abbe and Dr. 
Czapski relating to the subject ; but he thought the matter would hardly 
require extended publication. The point of interest to the Society was 
to be informed of the progress of the report of the committee on the new 
objective. The committee had not been able to meet during the 
vacation, and he regretted to have to state that the new slide forwarded 
by Dr. Van Heurck, in June, had become partially opaque like the 
one originally received with the objective. Dr. Van Heurck had 
recently found that the flint cover-glass became injured by the pro- 
longed exposure to the great heat required in mounting the objects in 
the dense yellow medium, and he had promised to forward another slide 
prepared with a different kind of flint cover-glass, with which he antici- 
pated less difficulty in securing permanency in the mounting. Until 
the arrival of the new slide, the committee could not usefully proceed 
with the examination of the new objective. 
The President gave formal notice that a special general meeting would 
be held in the Library at 5 p.m. on Wednesday, the 22nd inst., for the pur- 
pose of considering alterations in the bye-laws, the terms of which he read. 
Mr. G. C. Karop exhibited and described an improved student’s 
Microscope, made, at his suggestion, by Swift and Son. The new 
instrument embodied Nelson’s “horse-shoe” stage for convenience of 
readily seeing the condenser, and for estimating by the touch the 
approximation of the focus on the slide; on this stage the Mayall 
mechanical stage was easily applied. A centering substage was also 
adapted, which focused by sliding on the tail-piece. The whole instru- 
ment was of superior workmanship and design, and supplied at a 
moderate price. 
Mr. E. M. Nelson entirely approved of the aim of the design of the 
instrument. The general strengthening of the bearings throughout the 
mechanism was an important element in a Microscope for the use of 
students. He thought the plan of focusing the condenser by sliding it 
on the tail-piece was not good ; but should be replaced by a rack and 
pinion, which would add little to the cost. 
Mr. T. F. Smith said that all his own work in photomicrography 
had been done with a similar instrument ; but he thought that for high 
powers some rather more delicate kind of focal adjustment for the 
condenser would be essential. 
Prof. J. W. Groves read a note by Mr. Percival C. Waite “On a 
New Method of Demonstrating Intercellular Protoplasmic Continuity.” 
