ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 331 



A similar contrivance is also used for the web, mesentery, and 

 lung of the frog. 



Fig. 68. ^ . ^ 



Easy Metiiod of Making Micro-photographs.* — The only special 

 appliance absolutely necessary, according to Mr. F. C. Thompson, is 

 a small dark slide to carry an ordinary 3 by 1 in. glass slip. This 

 need be no elaborate piece of mechanism. The simplest form for use 

 with a 1 in. objective may be constructed as follows : — Take a slip of 

 mahogany 3| x 1^ iu. (it may be wider if the stage of the Microscope 

 allows of it) and 3/16 in. thick, and in its thickness make a shutter 

 sliding longitudinally. To do this, chisel out carefully and smoothly 

 a space 2^ in. long, 1 in. wide, and 1/8 in. deep, so as to leave 1 in. 

 at one end of the slip untouched, and 1/4 in. on each side. In this 

 shallow recess cut another, the depth of the thickness of thin sheet 

 zinc, or stout post-card. This is for the shutter to slide in ; let it 

 extend to 2i in. from the end of the slip, and be 3/-4 in. wide. Then 

 a piece of wood 2^ by 1 by 18 in., carefully glued in the larger 

 recess, will form a neat and light-tight groove. Before glueing in this, 

 however, the hole should be cut in the centre of the slip, through 

 which the picture falls on the plate. This need only be about 

 1/4 in. square, or the same diameter if round. Corresponding with 

 this must be another hole in the bit of wood forming the groove. 

 The shutter may be a piece of thin sheet zinc, or cardboard, of the 

 thickness of an ordinary stout post-card. 



On this slip thus fiu-nished with a shutter, glue strips of wood 

 about 1/16 in. thick, so as to leave space between them for a 3 by 1 in. 

 slip. In the corners of this space glue small pieces of thin wood for 

 the corners of the glass to rest upon, and keep the film from being 

 abraded. Another slip of wood of the same dimensions as that 

 described above, and likewise furnished with a shutter, hincred to 

 this plate-carrying arrangement, completes the dark slide — except a 



* Year-Book of Photography for 18S6, pp. 49-52. 



