demand I have had for them, has fully repaid my pains and ex-
pences, in bringing it to it’s prefent flate of perfection.
As the far greater part of the objefts which furround us are
opake, and very few are fufficiently tranfparent to be examined
by the common microfcopes, an inflrument that could be readily
applied to the examination o f opake obje&s, has always been a
defideratum. Even in the examination o f tranfparent objects,
many o f the fine and more curious portions are loft, and drowned
as it were in the light which muft be tranfmitted through them;
while different parts o f the fame objefl appear only as dark lines
or fpots, becaufe they are fo opake, as not to permit any light to
pafs through them. Thefe difficulties, as well as many more,
are obviated in the lucernal microfcope; by which, opake objects,
of various fizes, may be feen with eafe and diftm&nefs ;
the beautiful colours with which moft o f them are adorned, are
rendered more brilliant, without changing in the leaft the real
tint of the colour. The concave and convex parts o f an objefl
retain alfo their proper form.
The facility with which all opake objeas are applied to this
inflrument, is another confiderable advantage, and almoft peculiar
to itfelf; as the texture and configuration o f the more tender
parts are often hurt by previous preparation, every objeft may
be examined by this inflrument, firft, as opake, and afterwards
i f the texture will admit o f it, as tranfparent.
The lucernal microfcope does not in the leaft fatigue the eye.j
the objefl appears like nature itfelf, giving eafe to the fight, and
pleafure
67
pleafure to the mind: there is alfo, in the ufe o f this inflrument,
no occafion to fhut that eye which is'not dire&ed to the object
A further advantage peculiar to this microfcope is, that by it
the outlines o f every object may be taken, even by thofe who are
hot accuftomed to draw; while thofe who can draw well, will
receive great affiftance, and execute their work with more accuracy,
and in lefs time than they would otherwife have been able
to have performed it in. Moft of the defigns for this work were
taken with the lucernal microfcope | and, I hope, the accuracy
with which they are executed, will be deemed a fufficient
teftimony in favour o f the inflrument. In this point of view, it
will, I think, be found o f great ufe to the anatomift, the botanift,
the entomologift, &c. as it will enable them not only to mvefti-
gate the objea o f their refearches, but to convey to others
accurate delineations of the fubjeft they wiffi to defcribe.
By the addition o f a tin lanthorn to this apparatus, tranfparent
objefts may be thrown on a fcreen, and exhibited at one view to
a large company, as by the folar microfcope.
Tranfparent objefts may be examined with this inflrument in
three or four different-modes ; from a blaze of light almoft too
great for the eye to bear, to that which is perfectly eafy to it.
When this inflrument is fitted up in the heft way, we generally
fend a fmall double and fingle microfcope with it.
Fig. P Plate I. reprefents the improved lucernal microscope,
mounted to view opake objedts; A B O D E is a large
I 2 mahogany