10 
On a Dissecting Microscope^ &c. 
By James Smith. 
(Kead November 14tli, 1860.) 
This microscope, tlie general design of wMdilhopej with the 
assistance of the accompanying drawings, to make sufficiently 
plain, I consider to be a. modification of the one known as 
Slack^s Dissecting Microscope, and which is figured and de- 
scribed in Quekett^s ^ Practical Treatise/ It may be as weU to 
state in the first instance, that the chief novelty in the con- 
struction of my instrument, is the method of fixing on the 
hand-rests to the stage, by means of hinges — and in such a 
manner that, when not in use, they fold down at the sides — 
thus giving the advantage of fixed rests, available in a moment, 
while, at the same time, the microscope, when they are let 
down, is not larger than it would be if they were altogether 
separate from it. They also, when not in use, form with the 
other parts, a box (as in Mr. Slack^s model) in which the 
dissecting troughs and any other accessory apparatus may be 
packed away, when necessary. 
No. 1. 
The above drawing shows a front elevation of the microscope 
as set up for use, and in the following brief description I shall 
endeavour to give as clear an idea of it as I can, only premising 
that I have given the various measurements for the sake of 
greater distinctness, as I presume that the actual size of any 
particular instrument must, in some measure, depend upon 
the requirements of the operator. I think, however, that the 
one hereafter described will be found very convenient for all 
ordinary purposes. 
