varnish covering it; but, if the red-lead priming coat is made to dry right (if hurried work is to be done), or if a mixture of it and raw linseed oil are allowed ample time to dry, then the paint topping it will be permitted to live out its natural life. Red-lead plaster should always be protected by elastic coatings, the pigments largely composing which should have no chemical action on the binder, and should be repellent of water.

Orange mineral results from the calcination of white lead ; in the finished product the carbonic principle remains. It closely resembles red lead in composition and in its properties, but is more bulky and works better. Its use will probably increase.

White Lead.—White Lead is the best white pigment with one base known to-day. It  is  popular with  painters  because of its