50 Photographic Notes. 
To obtain Nearly-Absolute Alcohol without Distillation —If 
gelatine be suspended in ordinary alcohol, it will absorb the 
water, but as it is insoluble in alcohol, that substance will remain 
behind, and thus nearly-absolute alcohol may be obtained without 
distillation. 
Photographic Notes. 
The Silhouette—Having had some experience in this line, I 
will try to describe my modus operandi, which is very convenient 
and inexpensive. The things required are:—Two backgrounds 
standing on castors. These should, if possible, be of a dark 
colour ; if not, pieces of black calico can be hung over them. A 
third ground of white muslin and several yards of black calico. 
Now put the two dark backgrounds nearly parallel to each other, 
and far enough apart to place the sitter between them. Throw 
the pieces of black calico over the backgrounds, thus forming a 
tunnel, at the end of which place the white screen, tipped back 
slightly to reflect the greatest possible amount of light into the 
camera. At the other end put the camera, and focus on the 
sitter’s profile. Insert a small stop, so as to get the outline well 
defined. Should too much light enter this camera obscura from 
the side where the camera stands, shut it out by means of strips of 
black calico. A little light gives faint details, and is not at all 
hurtful—R. BENECKE, in Philadelphia Photographer. 
To make a Tank or Dish Water-tight.—Having tried many 
ways of treating tanks and wooden dishes to make them water- 
tight, I have hit on a method that is new to me, viz. :— 
Take equal weights of bees’-wax, paraffin, and resin; melt 
them in a sand-bath, mix well, and apply to the surface with a 
paint-brush. Cover the whole surface with the mixture, lay on 
strips of muslin about six inches wide, any length, as it can be 
stretched more evenly when narrow; iron the surface with a hot 
flat-iron. Do not have the iron hot enough to cause smoke. In 
this way cover the whole surface. It will last many months 
without repair, and needs only a little more of the mixture brushed 
over and ironed on to make a new surface. 
I have a 27 in. by 32 in. hypo. dish that has been in use over 
a year without repair. New dishes prepared in this way will 
outlast the plain waxing, as the strain of the dish while emptying 
solution does not crack the surface. If your wash-tank leaks, dry 
it out, coat as directed, and it will be all right—W. L. SHOE- 
MAKER, in Photographic Mosaics, 1888. 
To Clear Stained Negatives.—Yellow, pyro-stained negatives 
may be cleared by placing them in a solution of 2 parts common 
