There are two methods for grinding white lead in linseed oil for the market, the oldest being that still mostly followed, which is to mix the white lead in lump or powdered form, as it comes from drying pans, kilns or ovens, as the case may be, in suitable powerful mixers with linseed oil and chute it into the hoppers of large diameter stone mills, and when fine into coolers, and thence into various sized packages. The other method, which only came into general use twenty-five or thirty years ago, is the so-called pulp grinding process, in which the lead does not undergo any process of drying, but is placed in a suitable apparatus in the form of pulp, and therein agitated with a certain percentage of specially treated pure linseed oil until the lead and oil, which have great affinity for one another, unite and permit the clear water to rise to the top, which is then drawn off and the lead in oil passed over stone roller mills in order to eliminate all the remaining water possible. There is still a great difference of opinion as to which method of grinding, the dry or pulp ground gives best results as to the life of the paint made from either. Owing to theprejudice against pulp ground lead, some of the cor-roders have given up the process, but there is no doubt that not a few are still using it. The writer, in making exposure tests of paint made from either of the two grindings of lead, all other things being found equal by laboratory examinations, found that the paint from pulp ground lead did not show any chalking tendency inside of three years, while that from the dry ground lead chalked badly in less than eighteen months' time. Yet the surface on which the paints were applied was of the same seasoned lumber, white pine weather boarding put up for the purpose and exposed to the south, both leads mixed with the oil and driers from same package and in similar proportions. The chemist reported both leads free from appreciable percentages of lead acetate, the moisture in the pulp ground lead as .65 per cent, and that in the dry ground lead as .29 per cent, while the percentages of oil were alike in both pastes. The reason that pulp ground lead has been given a black eye by some authorities and by consumers may be looked for in the fact that through ignorance or carelessness in manipulation or the use of improper oil, an emulsion between some of the water and the oil was formed, especially in the presence of appreciable quantities of lead acetate. In describing the process of pulp grinding further on we shall touch upon this and other deficiencies.