G, a fmall brafs box to hold the filver fpeculum H.
H, a fmall filver concave fpeculum, defigned to reflefl the
light from the mirror on opake objects; it fhould only l e ufed
with the (hallow magnifiers. It is applied in different ways to
the compound microfcope; fometimes to a tube fimilar to
that reprefented at X, which Aides on the lower part o f the
body; fometimes it is fcrewed into the ring of the piece Q ; the
pin of this generally fits into one of the holes in the ftage. When'
this fpeculum is ufed, the Aider-holder fhould be removed.
I, a fifii-pan, whereon a fmall filh may be fattened, in order to
view the circulation o f the blood ; it’s tail is to be fpread acrofs
the oblong hole at the fmalleft end, and tied faft by means o f the
ribbon fixed thereto, by (hoving the knob which is on the back o f
it through the Ait made in the ftage; the tail o f the fiffi may be
brought under the lens which is in ufe.
K, a cylindrical piece, intended for the folar opake microfcope;
by pulling back the fpiral fpring, fmaller or larger obje&s may be
confined ia it.
L, a long fteel wire, with a fmall pair o f pliers at one end,
and a fteel point at the other'; the wire fiips backwards or forwards
in a fpring tube, which is affixed to a joint, at the bottom
o f which is a pin to fit one o f the holes in the ftage ; this piece is
ufed to confine fmall objefts. 1
1, a fmall ivory cylinder that fits on the pointed end o f the
fteel wire L ; it is defigned to receive opake objedls. Lightcoloured
coloured ones are to be (tuck on the dark fide, and vice
verfa.
K 2 is a pair o f triangular nippers, for taking hold and confining
a large objedt.
M, a convex lens, which fits the ftage by means o f the long
pin adhering to i t ; it is defigned to colleft the light from the fun
or a candle, and to throw them on any objefif placed on the ftage:
this piece is very little ufed at prefent.
N, a brafs Aider, into which is fitted a flat piece o f glafs, and
a brafs Aider, containing one or two fmall concave glafles, the
others flat; it is defigned to confine fmall living objefils, and
when ufed is to be placed between the two upper plates of the
Aider-holder.
O, a glafs tube to receive a fmall filh, &c.
P reprefents one o f the ivory-fliders, wherein objefts are
placed between two pieces o f talc, and confined by a brafs
ring.
Q, a piece to hold the fpeculum H ; this piece is generally
fitted to the microfcopes which are reprefented at Fig. 1 and 2,
Plate IV.
S, a
R, a pair o f forceps, to take up any occafional object.
O 2