chloroform, or carbon bisulphide, the two former being preferable, in the proportion of 10 grains to the ounce.
Ink Process. Under this title several processes may be included, but Lemling's process is the one usually meant by this term now ; the procedure being as follows: -
Bichromate of potash ...... ... I part.
Distilled water ... ... ... "... 20 parts.
Dissolve and render neutral with ammonia. To every three parts of this add
Powdered gum-arabic ... ...... 1 part.
Transfer to a bottle and shake frequently till dissolved ; it should then be filtered and spread evenly over a sheet of albumenised paper with the aid of a Blanchard brush. The paper should then be laid, film up, on a sheet of plate-glass, a good-sized pool of the solution poured on to it and made to cover it evenly, the excess poured off, and the paper hung up to dry. One difficulty in this process is to prevent the albumenised paper from curling; therefore it is preferable to hold it paper-side down over a jet of steam, so as to partially coagulate the albumen next the paper, and then lay on the glass ; or the glass may be wetted and the paper squeegeed to it with a rubber roller and then coated as described above. Exposure behind a negative in the usual way, the paper being then laid face downwards on water and allowed to soak for some time with repeated changing of the water, after which it should be soaked in alum solution and again washed. It is then drawn over the surface of the following solution: -
Pyrogallol ...... ... ... ... 1 part.
Distilled water ' ... ...... ... 5080 parts.
Or it may be floated on the same for two minutes, then thoroughly washed and floated on a solution of
Sulphate of iron ............ 10 parts.
Distilled water ... ... ..... 100 ..
and again washed. If not dark enough the process may be repeated. Another process sometimes used by artists and others for preparing drawings for reproduction is as follows. A print is obtained in the usual way either on albumenised, bromide, or plain paper, the latter being preferable ; and failing this an image