36 Cincinnati Society of Natural Fiistory. 
alkali) will bring out the detail. These are the Scylla and 
Charybdis upon which more hopes have been wrecked than any- 
thing else in photography. | 
My first experience with pyro and ammonia was, fortunately 
for me, decidedly disastrous; I managed to hopelessly fog every 
plate I attempted to develop, and the fumes of the ammonia 
affected me so unpleasantly, that I for once and all abandoned 
this combination. But with pyro and soda, and with pyro and 
potash, tle case was different. I think there must be not less than 
a thousand different formule for pyro developer, and I struggled 
along with one after another, with varying success, but failed to | 
realize that any of them possessed much advantage over the fer- 
rous oxalate, for which latter I have to this day a great fondness, 
and am never withoutit. I had read so much about the advan- 
tage of pyro over iron, that I was determined to find out all about 
it; but after floundering around until I was completely bewildered, 
I at length hit upon a formula used by Mr. F. C. Beach, of the 
New York Photographic Society, which comes as nearly being per- 
fect as any pyro developer I have ever used. It is extremely con- 
centrated, and for this reason valuable when one is on an extended 
trip, where it is impossible to get the ingredient of which it is 
prepared. The formula is as follows: 
Noji. Pyrogallic: eid) ane a eRe ae I OZ. 
Warm: Water 225 (oo Ans 
Sitlphite, Soda(Crystals) "95 2 a ae eae Aeros 
Dilute Sulphurous Acid: 42. = 3 ae 
Dissoive the sulphite of soda in the warm water, add the dilute 
sulphurous acid, then the pyro, and finally filter the solution. 
No. 2: Carbonate of Potash) >. 2.2. 4) ee 2°02 
W ater. oe ea A eres. Ca i gaia 
Dissolve. 
Sulphite of Sodan). er 2 OZ. 
Warm Water. 223.4. 0. ee Boos 
Dissolve, mix the two and filter the solution. 
For use, take one dram of each to two ounces of water, and 
add a few drops more of No. 1, from time to time, to secure 
desired density. This developer keeps well, and I can recommend 
it aS an excellent one. 
Whatever may be said of the good qualities of the pyro, it has 
the one exceedingly bad quality of staining everything with which 
