Early in this century works were established at Clichy, near Paris, for the manufacture of white lead by the process of Thenard. By this method litharge is dissolved in acetic acid, producing a solution of basic acetate of lead, through which a current of carbon dioxide is passed ; the ,reaction gives a precipitate of carbonate of lead and a solution of neutral acetate ; litharge is now added to the solution, and subacetate of lead again obtained, which is treated as the first, and thus the operation is made, in a way, continuous. This measure is entirely rational and completely ,under control. The product is very fine and white, but it is much inferior in opacity to the white lead made by the Dutch process. It has been used in France for many years, and to a small extent, some years ago, it was distributed to other countries of Europe. The works at Clichy had ,attained considerable proportions as early as 1809, when exhaustive experiments were made at Paris to prove the great superiority of lead made by this process over the ceruse de Hollande. 1 Writers of the early part of this century are unanimous in their statements of the prevalence ,of the custom of adulterating white lead, and nearly all condemn it. The confusion respecting the name given to the purer and better variety is exasperating. In the seventeenth and eighteenth centuries authors recommend the white lead of the Venetians as the purest and best, but in ,the early part of the present century that product disappeared from the markets of the European countries north of the Alps. The enterprise of the Dutch and of the English, their proximity to the sources of supply of raw material, together with their unscrupulous use of adulterants, enabled them to undersell the Venetians and to undermine their trade. Some authors of the period under consideration declare that the only pure white lead sold ,was the schieferweiss, blanc de plomb en ecailles, pieces of corroded lead as it came from the beds, or stacks, and without any grinding or washing.