294 
PROCEEDINGS OF THE SOCIETY. 
was read. (4) Six slides of Diatomaceae had been forwarded from 
America by Miss M. A. Booth— a Fellow of the Society. They were 
very neatly mounted, and were exhibited under Microscopes in the room. 
A letter from the donor was read. 
Mr. Andrew Pringle’s “ Note on Photomicrographs exhibited at 
the Meeting of the Society in November last, and on Kemarks made by 
Dr. Dallinger and Mr. Nelson,” was read. Mr. May all said that the 
fact noted by Mr. Pringle as to the photographic image spreading 
laterally was a new observation to him. Perhaps Mr. Nelson would 
say whether he had observed effects such as those mentioned by 
Mr. Pringle (see ante , p. 264). 
Mr. E. M. Nelson said he had not observed anything of the kind ; 
but he thought if correct methods were adopted, the object would be 
correctly represented by the image projected on the prepared plate. 
The w r hole difference was made by using small cones of light so as to get 
density of image. Of course, in that way they could easily get effects of 
that kind : by shutting up the condenser, for instance, they could 
double the image. 
Mr. Mayall read a translation of a note (see ante, p. 265) by M. Fayel, 
communicated to the Societe Linneenne de Normandie, of which he was 
president, suggesting a novel method of examining large opaque objects, 
wdiich he termed “ Photomicrography in Space.” The plan proposed 
by M. Fayel was to direct a photographic lens to the object, and focus 
the image upon the ground glass of the camera ; then he removed the 
ground glass, and viewed the aerial image with a compouud Microscope. 
Mr. Mayall thought it was by no means an easy matter to adapt a com- 
pound Microscope so as to be readily movable for inspecting different 
portions of the aerial image. The compound Microscope when so 
employed acted merely as an erecting eye-piece, and he thought M. Fayel 
must be mistaken in suggesting that powerful objectives might thus be 
employed with advantage. 
Mr. T. Charters White said “there was nothing new under the 
sun ” ; the description just given of the “ new ” method of examining 
large objects recalled to his mind a similar plan devised by the late Dr. 
J. Matthews for precisely the same purpose, and described and exhibited 
at the Quekett Club in February 1879, under the name of the Micro- 
megascope. Dr. Matthews used to place the object upon the table and 
form an image of it by means of an ordinary low-power objective, fitted 
into the tube of the substage with the front uppermost. This was then 
looked at through the Microscope in the ordinary way, and for exam- 
ining flowers and other large objects it was very effective. 
Mr. E. M. Nelson said the plan seemed like going all round the 
bush to get at a very indifferent result, because if they used a 2 in. 
objective upon the Microscope, they could take in an angle of 30°; 
whereas the photographic lens had practically no angle at all. This 
lens acted as a telescope object-glass, and the Microscope was used to 
magnify and erect just like the terrestrial eye-piece of a telescope. Zeiss 
did the same thing, only very much more perfectly, with his A * lens, 
which not only gave a great amount of light, but enabled the effect to be 
