260 
Transactions of the Society. 
grammatic figures given in the specification alluded to, but I have 
added additional letters to bring it into accord with the description. 
“ Fig. 1 represents the Instrument in a perspective view ready for 
Use. A, I call the Head of the Instrument, which has a Cup to 
receive the Eye ; to this Head is firmly fix’d a Plate, on which the 
Object Part B is mov’d backwards or forwards by the Leaver C, which 
turns out and folds in with the rest. I) is the Handle to turn up or 
down occasionally. E is a Plane Speculum or Looking-glass, with a 
split Shank that fits into a Socket at the End of the sliding Bar F. 
G G are Sliders, in which the Glasses are set between the Plates 
confin’d with two small Screws ; each of these Sliders has a little 
Spring to make it move in the Groove with a moderate Stiffness, that 
any Glass you would use, may stay before the Aperture I. KKK are 
three Pieces, which form a Stand for the Microscope, by fixing them 
together, turning out the Foot to a Triangle, and putting the End L 
(which is likewise a Turn-screw) into the Socket at the End of the 
Handle at M. N is a jointed Bar, with a Spring-Tube fitted to 
receive the Needle 0, which has a Point at one End, and a small 
Tongs at the other, to hold or stick any minute Objects. P is a Case 
containing 6 Sliders for Objects, one of which has round Plates with 
Holes between the Talks, and is intended to keep any minute living 
Creature, as a Mite, Flea, &c. Q is a Pair of Plyers to take up any 
small Bodies, and the other End is fop taking out the Bings that 
confine the Talks in the Ivory Sliders. K is a Box with Talks or 
Ising-Glass and Bings, to supply any that may be dropp’d or lost. 
S is a Plate having some Line wound on one End to tie a Fish, Frog, 
&c. on, to view the circulation of the Blood.” 
The following instructions are then given for viewing objects : — 
“ Transparent Objects are generally confined between two Talks in 
Ivory Sliders, such as are in the Case P. One of these being put 
into the Object Part B, the round Hole in the Brass Plate a , is a 
Guide to place the Object you would view before the Aperture I. 
Then having observed the Number of the Glass that is before the 
Aperture, and appears at the Top of the Head A, if you move the Object- 
Part of the Leaver C, till the Index b comes on the Line under the same 
Figure on the Scale c, which is on the Side of the Instrument, the 
Object will then be in a Point of Vision, and by the minutest Touch at 
either End of the Leaver C, the Object will be adjusted immediately to 
the Eye of any Person that is viewing it. If you think proper to 
make the Object bigger, put down the Brass Slider G, till the next 
Figure comes even with the Top of the Instrument, and move the 
Object-Part nearer, till the Index is at the next Division on the Scale 
under that Figure, and so on.” 
Among the six slides is one made of ebony, “ this has single Glasses 
in it” and is to be used for the examination of fluids. For viewing 
the circulation in the tail of a fish or in the foot of a frog, “ there is a 
Plate S. having on the End some small Line. This Plate is to be join’d 
