172 
CORRESPONDECE. 
FMontlily Microscopical 
L Journal, Sept. 1, 1869. 
The real origin of the instrument is as follows : — Several micro- 
scopes for dissecting purposes had been exhibited at our meetings, 
among others that by Messrs. Smith and Beck. Mr. Marshall after- 
wards suggested that this might be made more useful by certain modi- 
fications embodied in a model which he exhibited and explained, and 
in which the apparatus was stowed away under the stage, and the case 
was a square box slipped on from above, like a hood. 
The awkward part of this was that it was necessary to remove the 
apparatus from below the stage before beginning to work. It struck 
me that if, instead of the case being a square hood, it were made to 
open (by hinges) away from the stage, the apparatus could all be 
attached to the case, instead of encumbering the instrument. I made 
and exhibited at the Birmingham Natural History and Microscopical 
Society a model (which I have with me now in Jersey), from which 
most of the ideas appear to have been gleaned for the making of Mr. 
Marshall's microscope. 4^ 
May I trespass on your kindness so far as to give a few words of 
description of my instrument, touching on some of the points of simi- 
larity and difference between the two ? 
In order to use my microscope I place the box on the table, with 
the lock towards me, lift up the lid and throw it back, open back the 
two sides (which with the lid are hinged to the back), when the case 
may be pushed away to a convenient distance, and the instrument is 
ready for use. The turn-table, hot-plate, &c., are attached to the case, 
and not to the stage, so that I can examine an object, transfer it to the 
hot-plate, and then varnish it on the turn-tablo without loss of time in 
fixing and unfixing. 
This is a decided advantage, as if I am mounting a large number 
of objects I do not have to turn away the microscope arm, move the 
mirror, and change the stage -plate for the hot-plate, and vice versa, 
with each individual object, and my turn-table working on the case 
instead of the stage, I do not have to strain the microscope arm by 
using it " as a convenient support for the hand when making cement 
rings." 
My model was fitted to receive a compound body, but had not the 
arrangement for inclining the stand when used as a compound micro- 
scope. 
Among the apparatus I had a wash-bottle, hot- water bath, small 
benzoline lamp with mirror and condenser, stage forceps, zoophyte 
trough, animalcule cage, and several other things, in addition to most 
of those contained in Mr. Marshall's. These, of course, are, however, 
mere matters of detail ; the part which I claim as being my sole idea 
is the attachment of the entire stock of apparatus to the case, and the 
hinging together of this case in such a manner as to allow of the case 
and microscope being separated and brought into use in an instant. 
The size when packed is nearly a 7-inch cube. 
My model was in the hands of one of the London makers at the 
time Mr. Marshall's was sent to the Koyal Microscopical Society, and 
I was totally unaware that any one was working at the matter until, 
in May, a friend informed me that Messrs. Field had made up a 
