He CARBON TROCHSS 251 
Water 1000 ccm 2072: 
Use as above. 
QUICK-DRYING SENSITISER.—This is convenient, as the 
tissue will readily dry in from 15 to 30 minutes. 
Ammonium bichromate 60 g 460 gr. 
Water 1000 ccm i 1L@oz. 
Immediately before use mix 2 parts of the above with 3 
parts of alcohol or acetone. The tissue may be immersed in 
this for 3 to 4 minutes, or the solution may be painted on 
freely. The alcoholic mixture will not keep. 
SINGLE TRANSFER PapPer.—Brush over plain paper: 
Soft gelatine 60 ¢ — 460 er. 
Water 875 ccm 14 oz. 
Soak the geiatine for 30 minutes, dissolve in a water bath, 
and raise nearly to the boiling point; add with constant 
stirring : 
Chrome alum 1.25 ¢ 10 gr. 
Water 125 ccm 2 Oz. 
The mixture must be rapidly used and kept hot, or it will 
gelatinise. The following may be easily applied with a broad 
flat brush and dries rapidly: 
Soft gelatine Pe 54 gr. 
Glacial acetic acid 35 ccm 270 min. 
Water 275 ccm 44 oz. 
Soak the gelatine in the acid and water for 30 minutes, and 
dissolve by heat; add slowly with constant stirring: 
Alcohol 680 ccm 11¥Y, oz. 
Then add in the same way: 
Chrome alum 16¢ 12% gr. 
Water 14 ccm 110 min. 
This solution will keep. 
FLEXIBLE TEMPORARY SupporT.—Gelatinised paper is 
coated with a resinous solution. As a rule, a baryta-coated 
