art and science have extended the range 
of vision beyond that which was intended 
by nature to come within the scope of the 
human eye. 
A neat extension of microscopical work 
will be shown to-night by means of a pro- 
jecting microscope. This should not be 
confeunded with a stereopticon, which 
throws :nagnified pictures on the screen. 
In the case of the projecting microscope 
no picture or negative is used, but the 
object itself is placed in the iustrument 
and when you see the image on the screen 
it is just what you would see if looking 
down the tube of an ordinary microscope. 
A large audience is thus euabled to 
simultaueously view the same image just 
as if all were looking through one large 
microscope. 
‘This process while applicable to moder- 
ate powers does not possess the clearness 
of definition of the microscone itself and 
I would ask that you observe the greater 
clearness of the objects shown in the in- 
struments than those throwu upon the 
screen. 
It is to be regretted that at exhibitions 
we can show uuder the microscopes so 
few slides. Many of us have hundreds 
of slides, most of which are interesting, 
yet on such an evening as this we can 
select but one slide for each instrument 
and place it before you. What you see 
therefore at a microscopical exhibition is 
but the merest fraction of the exhibit 
which could be made were it mechanically 
possible to place our entire collections 
betore you. 
Many who have only seen slides under 
the conditions 11 which we show them 
this evening may gain the impression 
that alJ objects require mounting in per- 
manent form, whilein fact these mounted 
objects represent the smallest portion of 
the material which a mizroscopist passes 
through his instrument. 
Most of the work is done with live 
matter gathered from the ponds, woods 
and everywhere; mounted temporarily in 
water aud when viewed is wiped off the 
slide with no attempt at preservation. 
Asa rule the greatest interest centers 
in the observacion of living organisms in 
temporary mounts, but the difficuities of 
niaking public exhibitio : of such o jects 
cause most of the instruments to be shown 
with permanently mounted objects, while 
the other class are largely reserved for 
the private exhibitions which any of those 
who possess instruments are always 
pleased to give their friends 
In closing I wish to refer to the heirty 
cooperation of the Staten Island Academy 
with the interests of this Association, 
which is duly appreciated, and also to 
what I believe to be the wise policy of 
expansion adopted by the Association, 
8 
through which we take pleasure in includ- 
ing the public in the consideration of the 
many things of nature to which we devote 
such part of our time as can be allotted 
to the combining of recreation and the 
acquirement of kvowledge. 
The President’s remarks were followed 
by an exhibition of forty-five objects, 
shown on a screen by means of a pro- 
jecting microscope, after which there was 
anexhibition of selected objects under 
microscopes, as follows: 
1 Four microscopes made by Carl Reich- 
ert, of Vienna and loaned by Rich- 
ards & Co., No. 30 E. 18th street, 
New York, showing: 
a. Diatoms. 
b. Trichina spiralis 
c. Leeth of the medicinal leech. 
d. Anaspis melanopa. 
2. Living Wetella, showing circulation. 
THOMAS CRAIG. 
3. Arsenious and tartaric acids, mixed. 
Shown by polarized light. 
WALTER C. KERR. 
. Slide, showing 400 diatoms, with name 
of each photographed under each 
specimen. C. S. SNEAD. 
. Pelycistins from Barbados. 
C W. Hunt. 
6 Book louse. C. W. Hun’. 
Series of four rock sectious, each one accompanied 
by a hand specimen of the rock from which the 
section was taken; the first three shown under 
polarized light. 
[7-10 ] 
DR. ARTHUR HOLLICK. 
7. Fibrolite schist, from Boulevard and 
158th street, New York. A meta- 
morphic rock, composcd of fibrolite, 
biotite mica and quartz aud contain- 
ing garnets. 
8. Quartz-mica diorite, from Stony Point 
on the Hudson. An igneous rock 
composed of triclinic feldspar, mica 
and quartz. 
g. Diabase, from Graniteville, Staten Isl- 
and. An igneous rock, composed of 
triclinic feldspar and pyroxene. This 
is the rock which is extensively quar- 
ried at that locality, aud used for 
macadam. 
Nummulitic liumestone from San 
Domingo. A rock composed almost 
entirely of the tests of the small 
marine animal Nummutlites. 
Eye of horse fly. Wo. T. DAVIS. 
Gold crystals, devosited electrically. 
ALBERT W. JOHNSTON. 
Trichina spiratis, from human subject. 
Dr C. WILMOtT TOWNSEND. 
Section of huimmin scalp, showing hair 
follictes. DR. WM. C. WALSER. 
Iridescent leaves of a moss (Octobie- 
pharum albidum) which grows on 
palmettos in Florida and _ tropica) 
Ae: ica. Mrs. N. L. BRITTON. 
5 
10. 
Tike 
E2. 
13. 
14. 
15. 
