Aurine Automatic Photography
easily soluble in alcohol, is not destroyed by acids, and with alkalies turns more reddish. It has been used in orthochromatic photography, not only for sensitising plates, but also for the pre-paration of the coloured Screens (q.v.), and in the preparation of a solution which has been recommended as an addition to developers, so that plates could be developed in ordinary rooms without fogging. The formula of such a preparation is as follows: -
Aurantia ... ... ... ... ... 16 parts.
Carmine ... ... ... ... ... 8 ,,
Water............... 24 ..
Alcohol ......... ..... 24 ,,
Add sufficient ammonia to effect complete solution. Six parts of this to be added to every 100 of developer. Its use, we need scarcely add, is not to be commended.
Aurine. Synonyms: Rosolic acid, Yellow coralline. This is a dark, amorphous mass of reddish-green, iridescent tinge, formed by the treatment of carbolic acid with acids, etc. It is insoluble in water, but soluble in spirit and ether, which it colours yellow. It has been suggested to make non-actinic leather collodion, which should be poured on the back of the dry plate to prevent halation.
Autogravnre. A term applied to prints obtained by the Photogravure process (q.v.).
Automatic Oxygen Generators. Several devices exist in which the gas-holder itself controls the generation of the gas - a clever contrivance by Mr. G. R. Prouse being described in the Magic Lantern Journal for 1892. Another by Mr. Mcintosh, of Chicago, was very highly spoken of by Professor Burton. Still another form is described in the Magic Lantern Journal for November, 1901.
Automatic Photography. Several machines have been in-vented, consisting of mechanism set in motion by dropping a coin in a slot, and which are supposed to turn out photographs. Such devices have hitherto been unsuccessful, and generally it has been necessary to provide an attendant to look after the working of the machine. Semi-automatic machines, in which