. Acidity and acidimetry of soils. Soils. potassium chloride by first putting into the bottom of the carefully cleaned electrode cell a small amount of pure mercury to cover the platinum connection. No difficulty was experienced in getting electrodes to check within volt. The stopcock upon the tube leading from the calomel electrode was well greased and was opened only when readings were being taken. Con- nection was made to the U-tube c (Fig. 2) through a rubber stopper well driven home, making this side of the system practically gastight. HYDROGEN ELECTRODE—The platinum electrode was
. Acidity and acidimetry of soils. Soils. potassium chloride by first putting into the bottom of the carefully cleaned electrode cell a small amount of pure mercury to cover the platinum connection. No difficulty was experienced in getting electrodes to check within volt. The stopcock upon the tube leading from the calomel electrode was well greased and was opened only when readings were being taken. Con- nection was made to the U-tube c (Fig. 2) through a rubber stopper well driven home, making this side of the system practically gastight. HYDROGEN ELECTRODE—The platinum electrode was prepared by plating as a cathode in a one per cent solution of platinum chloride, containing a small amount (about per cent) of lead acetate to cause the platinum black to adhere. Attempts were made to use a solution of pure platinic chloride as recom- mended by Ellis, but this proved unsatisfactory as the platinum black invariably washed off within a few minutes after being placed in the cell. AceuhiuLKreR. r€^ + + - + - POTEMT IOMETER Fig. 3 In plating a platinum anode was used. The strength of the current was varied from time to time but no variation in the potentials of the electrode or in the time required to become saturated was noted from this cause. If the evolution of hydrogen was too lively some of the platinum black was loosened. The plating was continued from i to 2 hrs., or until a good heavy •'5). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Knight, Henry Granger, 1878- [from old catalog]. [Easton? Pa. ]
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectsoils, bookyear1920
