258 Transactions of the Royal Microscopical Society. 



II. — Notes on Miero-j^hotography. 



By Surgeon-Major Edward J. Gayer, H.M. Indian Army, now 

 Professor of Surgery, Medical College, Calcutta. 



{Read before the Royal Microscopical Society, May 3, 1876.) 



Plates CXLI. and CXLII. 



The best micro-pliotograplis can of course only be produced by 

 tbe best objectives ; but besides this many things are required, and 

 as much as anything else, good manipulation. You may have a 

 very good light and the most perfect form of apparatus, and yet, 

 from want of sufficient control over all, really good work may not 

 be the result of the expenditure of much labour and time. It is 

 manifest that the best position for the operator during the whole 

 manipulative process (except of course the photographic part of 

 it) is near the microscope condenser, mirror and source of light, 

 and not far away from aU this apparatus at the focussing screen 

 and dark slide. To be able to stand in a comfortable position 

 within easy reach of your microscope and the other apparatus, and 

 to be able to view your focussing screen and sensitive plate, watch- 

 ing the light, and altering it if you wish it at any time during the 

 process, affords great facility to the worker. All this can be readily 

 accomplished by the use of a small telescope, and with its help a 

 very small quantity of special apparatus is required. The writer 

 has worked for many years with the form of apparatus figured in 

 PI. CXLI,, which consists of a common, heavy, strong table A, 

 about 12 feet long and 2 feet wide. At one end of this table the 

 mirror D is placed near enough to the source of light B and the 

 cell for cutting off heat rays C, to allow of all being easily 

 reached even when the eye is applied to the telescope N. The 

 condenser E, the microscope F, with its condenser H, its object- 

 glass G-, its stage and fine and coarse adjustments, are all close 

 together within easy reach of both hands all through the pro- 

 cess. The focussing screen L and dark slide are at the other end 

 of the table, and are made movable so as to slide up and down on the 

 ledge 0, in order that the distance between them and the micro- 



