about twelve hours, or at the latest the next morning if the starch is put on in the afternoon, the paste must be carefully pulled off with the fingers. In general the dirt will be taken off with the paste. Should dirt, however, stick to the cast anywhere, it will be loose and can easily be removed by a gentle wiping with a damp sponge which must be washed and squeezed out in fresh cold water. The starch must not remain on the cast longer than one day, as otherwise it becomes too dry, and in tearing off it takes the plaster too, and thus injures the surface. The same result occurs if the layer of paste which sticks to the cast is too thin.
If large statues or groups are to be cleaned the starch must be prepared in larger quantities and the paste put on beginning at the top. The process must not be interrupted until the whole is covered. Before attempting to apply the starch paste, the cast should be carefully examined to determine whether it has already been treated in any way or whether the plaster is still in the raw state. Casts which have never been treated or those which have been painted with water colors may easily be cleaned by the application of the starch paste. Great care should be taken that the paste is of the right consistency, as otherwise the cast may receive some damage.
There is a way of treating the new cast chem-
