(1) The tendency of the film on gelatine plates to "frill" and rise up off the glass during development is very common when the solutions are warm. A remedy described by Watmough Webster, which, in his experience, has proved to be valuable and useful, is as follows. After the frilled negative has been fixed, it is washed a few minutes, and then immersed in an alum solution for 1 hour; it is again washed and soaked for 12 hours - overnight, for instance - in a dish containing alcohol; the dish should be covered with a sheet of glass to prevent the evaporation of the alcohol. At the end of 12 hours the frilling or blistering will have entirely disappeared.

(2) Soak the plate before development in a saturated solution of Epsom salts (magnesia sulphate); wash and develop as usual.