For this purpose a large basin or dish should be used, filled with the above borax solution. The plate, after its final washing, is stood in a rack for a few minutes to drain off the surplus moisture. The penknife is then very carefully passed along the fourth edge of the film, cutting through it by means of a series of pressures, not by drawing the blade along, for the latter method would pucker or tear the moist film. The plate is now placed in the basin, and the film will float off the glass, which can then be with drawn. Using a moderately large camel hair brush, turn the film over in the solution so that the collodion side is downward. Great caution must be used not to damage the loose film or abrade the powdered side, and the fingers should on no account be employed. The plaque or other support is next carefully intro duced under the floating film, which is guided into its correct final position. The
support is then slowly, and by degrees, lifted out of the water with the film adhering. The powder side of the latter, as before stated, must be uppermost. If the dish is small, it may be as well to place the plaque ready in position before float ing off the film, using a small china block, or anything else found suitable, to raise it from the bottom, since if this is not clone it may be awkward to move it when re quired. When the support is withdrawn, with the film satisfactorily attached, it should be placed on a few sheets of blotting paper to dry, on a level surface. When dry, any loose pieces of film which have strayed over the back or margins may be removed with a clamp sponge.