326 PHOTOGRAPHIC FACTS AND FORMULAS 
Picked white gum arabic 62.5 g YZ oz. 
Dextrine 290 g 2% Oz. 
Ammonia 1 ccm 4 drops 
Phenol (carbolic acid) 15 ccm 60 min. 
Water » 1000 ccm 8 oz. 
Powder the gum, and mix with the dextrine into a smooth 
paste with one-fourth of the water; then add the rest of the 
water, and boil for 10 minutes. Strain through linen, and 
add the phenol and ammonia when cold. 
GELATINE.—This must be used hot. A piece of ground 
glass should be dipped in hot water, drained, and the mount- 
ant brushed over. The print is then laid face up on the 
pasted surface, rubbed gently into contact with a piece of 
paper, and is then pressed on to its mount: 
Soft gelatine 187.5 ¢ 3 oz. 
Water 750 ccm 12% oz. 
Soak the gelatine in the water, melt in a water bath, and add 
slowly with constant stirring: 
Methyl alcohol 225 ccm 4 oz. 
Glycerine 25 ccm 96 min. 
It is preferable to omit the glycerine, and use corn or sugar 
syrup, or add sugar in the same proportion. 
Liguip GELATINE.— 
Gelatine 100 g 1 oz. 
Water 600 ccm 6 oz. 
Chloral hydrate — 100g 1 oz. 
Soak the gelatine in the water, melt by the aid of heat, add the 
chloral, heat for 15 minutes, and then add sodium carbonate 
until the mixture is neutral to litmus paper. 
STARCH-GELATINE.— 
A. Bermuda arrowroot 200 g 8 oz. 
Water 100 ccm 4 oz. 
B. Soft gelatine 20 g 360 gr. 
Water 1600 ccm 64 oz. 
