One of the most novel and practical of the numerous methods proposed was patented by Pattinson in 1849. After taking out patents in 1840 and in 1841 for processes depending upon the reaction of carbonates of lime and of magnesia upon chloride of lead, he patented his process for the manufacture of oxichloric of lead, which is described as "the manufacture of oxichloric of lead, composed o one atom of oxide of lead, one atom of chloride of lead, with or without an atom of water, by the use of chloride of lead, and lime, soda, potash, ammonia or baryta; lime is preferred, and on mixing limewater and chloride of lead in solution, both in certain proportions, this substance instantly forms and subsides." In practice the lead ore, galena, "is ground with hydrochloric acid, and in thirty or forty hours the lead and associated metals in the ore are converted into chlorides; a portion, however, from seven to ten per cent, is either unacted upon, or converted into sulphates by the traces of sulphuric acid contained in the hydrochloric acid. The impurities are eliminated, and the mass is then introduced into tubs furnished with agitators, and a stream of hot water is allowed to flow in, the chloride of lead is gradually dissolved and precipitation is effected by means of lime, a perfectly clear solution of which is allowed to unite in astream with a stream of the solution of chloride of lead."