86 COLLODION EMULSION. CONCLUSION. In the foregoing chapters will be found an indication as to the position collodion emulsion holds at the time of writing. The wet plate will be chiefly used for line work and there production of black and white subjects in half tone, in the first instance on account of superiority of results, in the second on account of expense and the disturbance to business routine, which may probably result through the introduction of a new process with which a great proportion of operators are not familiar. The dry plate, and in particular the orthochromatic dry plate which has reached such a high point of excellence, will remain to offer the best working methods for out door work, for portrait, landscape, and indirect tricolour reproduction in picture galleries. Collodion emulsion will step in where the others fail, or prove to be too expensive. For direct three-colour half-tone work, the reproduction of paintings in mono chrome, for ferrotype dry plates, lantern slides and transparencies, wood engraving, collodion emulsion will find no equal. In the hands of the intelligent operator, it will prove a reliable and a pliable process, for it will permit of no end of variations to suit certain requirements, but to the careless “ slap dash ” worker it will be a probable cause of his being visited by the most aggra vating and apparently mysterious troubles he may ever dream of. This chiefly accounts for the bad reputation collodion emulsion at one time enjoyed in certain quarters, and for the heartbreaking work of its re-introduction.