THE AMERICAN 
MONTHLY 
MICROSCOPICAL JOURNAL. 
Vor. VIII. MARCH, 1887. No. 3. 
Photo-micrography 
(Continued from vol. vit, p. r4r). 
In continuing these articles, after an unexpectedly long, but unavoidable, 
intermission, we have thought it well to bring them to a close by an account 
of the ordinary method Oia silver printing. HOE all the various methods of 
printing that are now known and practised, we are of the opinion that for 
microscopical subjects there is not one that is so generally satisfactory as 
the ordinary method with albuminized paper. It is true, excellent prints 
can be made with paper coated with silver emulsion, and particularly by the 
platinotype process; and for purely artistic effects, with suitable negatives, 
we are disposed to favor the platinotype process more than any silver pro- 
cess. But for the more delicate details required in microscopical prints— 
details which sometimes are exceedingly faint even in the best negatives— 
the smooth albuminized surface alone, in our opinion, will give entire satis- 
faction. On the other hand, for most of the work of amateurs with ordinary 
subjects, the. other methods leave nothing to be desired. 
Sensitizing the paper.—The sensitizing solution is prepared by dissolving 
sixty g grains of nitrate of silver in each ounce of water. <A sufficient quan- 
tity should be prepared to cover the bottom of the sensitizing tray to the 
depth of half an inch. Albuminized paper comes in sheets measuring 18 by 
22 inches. If one has a tray large enough, it is well to silver the sheets en- 
tire, but usually the amateur aati find it convenient to cut the sheets in quar- 
ters and to sensitize the smaller pieces in an ordinary 10 < 12 or 8 » 10 por- 
celain or rubber tray. To do this, filter the solution into the perfectly clean 
tray. and, taking a sheet of the paper, lower it, working by yellow light or 
by lamp light, upon the solution, slowly and steadily, beginning with the left- 
hand corner. Do not get any silver on the back. 
Be very careful not = include any air bubbles in this operation. They can 
be detected by raising the paper and examining the surface. As the edges 
of the paper tend to ‘carl up, breathe upon the Wicks and they will again flat- 
ten out. Allow the paper to float about two minutes, at ordinary tempera- 
tures. Then remove it by taking hold of the two corners and drawing it 
slowly over the edge of the tray, to avoid waste of silver. Lay the paper, 
face up, on a clean smooth surface, and immediately take up all superfluous 
fluid from its surface with a sheet of blotting paper. Then hang it up to dry. 
As it is desirable to keep the silver as much on the surface of the paper as 
possible, in order to give brilliancy to the prints, the more rapidly it can be 
dried the better. Artificial heat may, therefore, be employed with advan- 
tage, and it may be of interest to some of our readers if we describe the method 
of drying we have adopted in Japan, where the appliances at hand are quite 
different from those at home. We have a very large covered box in which 
is placed a Japanese h¢6acht—a kind of earthen brazier, with glowing char- 
