2. In the above methods the manufacture of white lead commences with the production of white lead from metallic lead and acetic acid. In the so-called French method a solution of basic lead acetate is decomposed by carbonic acid into white lead and neutral lead acetate, which latter is again converted into basic acetate. 3. The English method. The principle of this process consists in moistening litharge with a solution of lead acetate and exposing it to the action of carbonic acid, whereby white lead is formed. Methods for manufacturing white lead, which are often advanced as entirely new processes, may be always traced to one of the above, from which they deviate but little in principle, and the deviations cannot always be regarded as improvements. In the following detailed account of the manufacture of white lead we shall adhere to the classification just given, according to which there are three principal methods: (1) Manufacture of white lead from metallic lead, acetic acid and carbonic acid (Dutch and German processes); (2) manufacture of white lead from basic lead acetate (French process); and (3) from litharge moistened with lead acetate solution (English process). We should remark that every year “new” processes for the manufacture of white lead are patented. The majority of these will not be mentioned; to those acquainted with the principles of chemistry they at once appear impracticable. MANUFACTURE OF WHITE LEAD FROM METALLIC LEAD. (a) DUTCH PROCESS. This essentially primitive process, when properly conducted, produces white lead of good colour and covering power, which are the properties for which this pigment is valued. It is now seldom used,[2] because other methods give a product of equal colour in a shorter time. It is, however, of economic interest, as showing how a branch of industry may rise from crude beginnings to a high state of perfection. The operations comprised in the Dutch process are as follows:— [2] In England the Dutch process is in general use.—TRANSLATOR. (1) Casting the lead into sheets; (2) placing these sheets in pots and arranging the pots in the stacks (placing the pots containing lead and acetic acid in the bed of manure); (3) removing the pots from the stack; (4) separating the white lead formed in the pots; (5) further purification of the impure white lead by grinding, washing and drying. 1. =Casting the Lead into Sheets.=—At first sight it would appear unsuitable to cast lead in sheets, since this metal can be readily rolled into sheets of any thickness. Experience has, however, shown that rolled lead is only slowly attacked by acetic acid vapours, whilst cast sheets are rapidly attacked.