OZOUV EE AND AMIE D PROCESSES 7 (297 
lesser quantity of A; for normal negatives use 21 ccm 
(34 oz.) ; and for large prints from soft negatives use the full 
quantity of A. The pigment tissue should be immersed in 
the above for 30 seconds, the print also immersed therein 
and brought into contact face to face, lifted out, thoroughly 
squeegeed, and left in contact as advised for the first bath. 
If the two are left in contact for more than 14 hours, they 
should be afterwards immersed in cold water for from 30 to 
45 minutes. Development may be effected as in the carbon 
process with water from 43° to 46° C. (109° to 115° F.). As 
soon as development is complete, the print should be im- 
mersed in a 5 per cent solution of alum or: 
Alum 28 g 1 oz. 
Hydrochloric acid 1.7 ccm 30 min. 
Hydrochinon 0.6 ¢ 10 gr. 
Water 560 ccm 20 oz. 
for the same time, and then washed. 
OzosproME.—In this process, pigmented tissue impregnated 
with a bichromate and ferricyanide is brought into contact 
with a bromide print. The metallic silver reduces these com- 
pounds, and the gelatine is hardened in contact with the 
silver, so that it becomes insoluble in hot water, just as 
though it had been exposed to light. Practically, it is a 
carbon process, in which chemical action does the work of 
light; it is, therefore, possible to carry out the process at 
night, and many carbon prints may be obtained from one 
bromide, if thought desirable. 
Any good bromide print may be used; but the best results 
are obtained with those not on baryta-coated paper. The 
print should be first hardened by immersion for 5 to 10 
minutes in a 5 per cent solution of alum, or formaldehyde, 
or a 4 per cent chrome alum solution, washed, and dried. The 
ozobrome or sensitising solution is as follows (Manly) : 
