The residue is digested with hot water, filtered through a small filter, and washed with successive small portions of water until the filtrate amounts to thirty cubic centimeters or more. To this filtrate, add two drops of hydrochloric acid, in a porcelain dish, and from five to ten cubic centimeters of a solution of ten grams of platinic chlorid in 100 cubic centimeters of water. The mixture is evaporated on a water-bath to a thick sirup, as above, treated with alcohol of eighty per cent strength, washed by decantation, collected in a gooch or other form of filter, washed with strong alcohol, afterwards with five cubic centimeters of ether, dried for thirty minutes at 100°, and weighed. It is desirable, if there be an appearance of foreign matter in the double salt, that it should be washed, according to the previous method, with ten cubic centimeters of the half-concentrated solution of ammonium chlorid, which has been saturated by shaking with potassium platinochlorid. =253. Method of Solution for Organic Compounds.=—In case the potash is contained in organic compounds, like tobacco stems, cottonseed hulls, etc., weigh ten grams, saturate with strong sulfuric acid, and ignite in a muffle to destroy organic matter. Add a little strong hydrochloric acid to moisten the mass and warm slightly so as to loosen it in the dish. Proceed then as in the lindo-gladding or alternate method. =254. Factors.=—The use of the factors 0.3056 for converting potassium platinochlorid to potassium chlorid and 0.19308 for converting it to potassium oxid is advised. The latter number is almost identical with that used by the Halle and Stassfurt chemists _viz._, 0.1927 and 0.1928 respectively.