terials, one must know the following things about them; namely:

A—Their history and mode of pre-

paration.

B—Their physical properties.

C—Their chemical properties.

3. That a competent paint-maker can design a paint to meet any reasonable conditions of location, atmosphere, tem- perature, surface, application, drying, and wear, but that in order to do so he must know the conditions; that these being known he should be entrusted with the manufacture of a coating to accomplish the results desired.

4. That the priming, or first coat of paint, upon any surface, is the most important one, and that it should form an inhibitive, firm, unyielding, and receptive foundation for those to follow it.