846 
PROCEEDINGS OF THE SOCIETY. 
of various kinds, not only in London and in the provinces, but through- 
out America ; and these are doing most valuable work. Their value 
consists not merely in the constant accumulation of new details con- 
cerning minute vegetable and animal life, and the minute details of 
larger forms, but in the constant improvement of the quality of the 
entire Microscope on its optical and mechanical sides. It is largely to 
amateur microscopy that the desire and motive for the great improve- 
ments in object-glasses and eye-pieces, for the last twenty years are due. 
The men who have compared the quality of respective lenses and 
specific ideas as to how these could become possessed of still higher 
qualities, have been comparatively rarely those who have employed the 
Microscope for professional and educational purposes. They have the 
rather simply used — employed in the execution of their professional 
work — the best with which the practical optician could supply them. 
It has been by amateur microscopists that the opticians have been 
incited to the production of new and improved objectives. But it is the 
men who work in our biological and medical schools that ultimately 
reap the immense advantage — not only of greatly improved, but in the 
end greatly cheapened, object-glasses. It is on this account to the 
advantage of all that the amateur microscopist should have within his 
reach a handbook dealing with the principles of his instrument and his 
subject.” ' 
The President thought this was a very valuable book, which the 
“ amateurs ” would find to be a means of great help in the course of 
their studies. 
Prof. Bell also called attention to another work, entitled ‘ The 
Microscope in Histology,’ by Prof. S. H. Gage, which t had reached its 
third edition, and was perhaps more satisfactory than most books of its 
kind. 
Mr. C. Lees Curties exhibited and described a small heliostat made 
on the lines laid down by Mr. Comber. It would be found both simple 
and effective, and was adapted for use in any latitude between 15° 
and 70°. 
Mr. J. W. Gifford read a short paper “ On the Mounting of 
Ampltipleura pellucida. 
The President expressed the thanks of the Society to the author for 
his communication. 
Mr. E. M. Nelson said it would be remembered that some discussion 
took place at their last meeting as to the value of drawings made with 
Dr. Beale’s neutral tint reflector, and to test the matter more closely, he 
had made a drawing of the ten lines on a micrometer scale of 1/100 mm. 
under an apochromatic objective giving a magnifying power of X 850. 
It was not possible to draw more than five or six of these lines at one 
time, but he had indicated the relative position of these by dots upon 
paper, and found that as measured with an ordinary rule they showed a 
very slight displacement. He therefore came to the conclusion that the 
Beale’s neutral tint reflector was a very good thing for the purpose of 
