Repository: UIHistories Project: Board of Trustees Minutes - 1880 [PAGE 122]

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120 Manganese.—The solution from which the iron and phosphoric were precipitated was treated with a few drops of bromine, and boiled to precipitate the manganese. The precipitate was collected upon a filter and thoroughly washed, then strongly ignited, and weighed. Lime.—The above filtrate was concentrated, and while hot a little ammonia added, and then an excess of animonium-oxalate, to precipitate the lime. The mixture was allowed to stand 12 hours. The precipitate was then collected upon a filter, washed, dried, and ignited in a platinum crucible. After the filter was reduced to* ash, carbonic acid was passed over the ignited lime, to reconvert any: oxide formed into carbonate. From the weight of calcium-carbonate thus obtained the per cent, of lime was estimated. Magnesia.—The filtrate from the lime was concentrated, ammonia added in excess, and then a solution of phosphate of soda to precipitate the magnesia present. This precipitate and its filtrate were treated the same as the corresponding one, the estimation of phosphoric acid. The magnesia was estimated from the amount of pyrophosphate of magnesia found. Sulphuric Acid.—The 50 c. c. of the solution reserved for this purpose were boiled, and the sulphuric acid precipitated, with a slight. excess of barium-chloride. The precipitate was collected upon a filter, washed, ignited and weighed. Potassa.—The above solution was treated, after concentration on a water-bath, with ammonia and ammonium-carbonate as long as any precipitate was formed, digested on a water bath, filtered, and the contents of the filter carefully washed. The filtrate and washings were evaporated to dryness on a water bath, and the residue ignited to expel ammoniacal salts. This residue was then treated with five and one-half times its weight of pure oxalic acid in the form of a concentrated solution, then evaporated to dryness, and again ignited to dull redness. The ignited residue was treated with a small quantity of boiling, water, thrown upon a filter, washed with hot water, hydrochloric acid added to the filtrate, the mixture evaporated to dryness, and gently ignited, and the weight of the alkaline chloride ascertained. The separation of the alkalies was effected with platinic chloride, as follows: The residue of alkalies was dissolved in a little water, and enough platinic chloride added to combine with the alkalies estimated as potassium salt. This mixture was evaporated nearly to dryness over a water bath, care being taken not to boil the water. A mixture of six volumes of alcohol and one of ether was poured over the residue, and the whole allowed to stand several hours in a covered vessel, with occasional stirring. The insoluble potassio-platinic chloride was transferred to an equipoised filter, washed with alcohol and ether mixed, and finally dried at 100° C , and weighed. Soda.—From the weight of the double potassium chloride, the amount of the potassium chloride was ascertained. This wTeight was. subtracted from the weight of the combined alkali chlorides, and the remainder called sodium chloride, and estimated as soda. Carbonic Acid.—One grain of the ash was transferred to a Eose carbonic acid apparatus, and the carbonic acid estimated by loss.