used and the manner of applying it are of the utmost importance.
Wooden objects which come from excavations often need special treatment. Impregnation with paraffin is one of the simplest things that can be done and is quite efficacious.
Ironwork.—Under this head it is necessary to make a distinction between the different classes of objects, for while the enemy is the same in every case, the remedy is different.
In the great European collections of armor, a man is kept at work constantly burnishing the pieces in rotation in a manner very similar to that used by his ancestors in preparing the knight for battle. As each piece is freed from rust it is coated with a thin filament of pure oil, not kerosene, for that has been proved to increase rather than diminish rust. Finger marks cause rust quicker than anything else, so that in handling a collection of this kind gloves are necessary. Old locks, keys, etc., may be freed from rust by boiling in water and scraping, and should then be treated with oil to keep them in condition.
Exhaustive experiments have been tried in the chemical laboratory of the Berlin museums. It has been proved that an object once thoroughly freed from rust and not handled will show no signs of returning trouble. The difficulty is, there-
