February, 1924
INDUSTRIAL AND ENGINEERING CHEMISTRY
insure enough copper hydroxide to completely remove the colloidal carbon on filtration.
DISCUSSION OF THE ANALYTICAL PROCEDURE This procedure is similar to that of Beak4 in that copper sulfate and hydroxide are used for clarifying and decolorizing the soil extract. The writer found that the copper, as copper hydroxide, could be more advantageously precipitated with calcium hydroxide in the cold than with magnesium oxide and heating, and that this precipitation in most cases could be accomplished in the soil suspension. Magnesium carbonate is added to remove the excess of calcium hydroxide. This procedcire is simple and rapid and an alkaline extract is also obtained which prevents loss of nitrate, as shown by Davis,8 who used potash alum as a flocculent. It was found that flooding the residue with an excess of phenoldisulfonic acid as recommended by Davis8 is necessary to prevent loss of nitrate when considerable carbonates are present,. The reason for this has been explained. The use of copper sulfate and its removal as outlined in placeof potash alum gives a solytion which is seldom acid to phenolphthalein and contains much smaller amounts of soluble salts. The residue is thus smaller, contains less carbonates, and hence a less amount of phenoldisulfonic acid$ necessary for flooding than that recommended by Davis.8 The writer has found ammonium hydroxide preferable to Dotassium hvdroxide for the neutralization of the Dhenoldiklfonio acid: The use of potassium hydroxide gives rise to often than the use of insoluble precipitates much ammonium hydroxide. The ammonium hydroxide is also a much more convenient laboratory reagent. The us8 of properly prepared phenoldisulfonic acid is important). This reagent is prepared according to Chamot, Pratt, end Redfield,l7 as follows: Dissolve 25 grams of pure phenol in 150 cc. of concentrated sulfuric acid. Add 75 cc.
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of fuming sulfuric acid, mix, and heat in a flask by placing the flask in boiling water for 2 hours. Store in a brawn bottle. The standard nitrate solution was made according to directions given by Bear and Salter.4 The analytical procedure given embodies the best points of several methods with certain modifications of the miter.
ACKNOWLEDGMENT The writer wishes to express his appreciation of the suggestions and criticisms offered by Professor E. Truog in connection with this study. BIBLIOGRAPHY I-Tieman-Gartner, “Handbuch der Untersuchen und Beurteilung der Wasser,” 4th edition, 1895. 2-U. S. Dept. Agr., Bur. Chem., Bull. 107. 3--Whiting, Richmond and Schoonover. J . I n d . Eng. Chem., 12, 982 (1920). 4-Bear and Salter, W. Va. Agr. Expt. Sta., Bull. 159,23 (1916). 5-Lipman and Sharp, U n i v , Cali,?.Publications i n Agricultural Science, 1, 21 (1912). 6--Noyes, J . I n d . Eng. Chem., 11, 213 (1919) 7-Potter and Snyder, I b i d . , 7, 863 (1915). 8-Davis, Ibid., 9, 290 (1917). 9-Comber, J . Agr. Sci., 11,450 (1921). 10-Wolkoff, Soil Science, 1, 585 (1916). 11-Emerson, l b i d . , 12, 413 (1921). 12-Schreiner and Failyer, U.S. Dept. Agr., Bur. Soils, Bull. 31. l3-Chamot, Pratt and Redfield, J . A m . Chem. SOC.,33, 366 (1911). 14-Stewart and Greaves,lbzd., 32, 756 (1910); 36,579 (1913). 15-Lombard and Lafore, Bull. SOC. chim.. 6, 321 (1909). 16--Pouget, Ibid., 7, 449 (1910). 17-Chamot, P r a t t , and Redfield, J . Am. Chem. SOC.,38, 381 (1911). 18-Allen and Bonazzi, Ohio Agr. Expt. Sta., Tech. Series, Bull. 7 (1915). 19-Potter and Snyder, J . Am. Soc. Agron., 8, 54 (1916). BO-Kelley and Brown, S o i l Science, 12, 261 (1921). 21-Gustafson, I b z d . , lS, 173 (1922). Trans. Wisconsin Acad. S C L ,16, 275 (1908); abitracted in 22-King, ~ ~ psta. t .Record, 21, 19 (1909).
Erskine Douglas Williamson T H E death of Erskine Douglas Williamson on December 25, group which went out into the factories and supervised the 1923, several days after an operation from which he seemed manufacture of optical glass for military needs. His particular to be recovering, was a sudden blow to his friends and colleagues field was the annealing of glass, and investigations begun while he was a t the glass plant were completed later a t at the Geophysical Laboratory. Born in Edinthe Geophysical Laboratory. For his share in burgh, Scotland, on April 10, 1886, he was only this investigation the Franklin Institute awarded thirty-seven a t the time of his death. him in 1921 the Edward Longstreth Medal of Mr. Williamson obtained his early education Merit. Another wartime activity in which he at George Watson’s College in Edinburgh, where took part was the determination of the compressihe showed marked ability in science and mathebility of mustard gas. Since the close of the war matics. He graduated with high honors from he has been engaged in the investigation of several the University of Edinburgh, receiving the degrees phases of the behavior of materials under very of B.Sc in 1908 and M.A. in 1909. During the high pressures, particularly the compressibility of two years 1910 to 1912 he was science master in solutions and of minerals and rocks, the transGalashiels Academy, which he left to take up remission of earthquake waves, and the bearing search work in physical chemistry a t the Uniof these on the constitution of the interior of the versity of Edinburgh. While here he was granted earth. His latest activity was the construction a Carnegie scholarship, and in 1914 he went to of an apparatus for the determination of gravity. America to take a position on the scientific staff This work was unfinished a t the time of his death. of the Geophysical Laboratory of the Carnegie CHEMMr. Williamson joined the AMERICAN Institution of Washington. ICAL SOCIETY soon after coming t o this country By training a mathematician as well as a physand contirued to be an active member during the ical chemist, Mr. Williamson was able t o bring ensuing nine years. He was also a member of the this happy combination of faculties t o bear upon problems in many fields of scientific endeavor. AlEdinburgh Mathematical Society, a fellow of the E. D WILLIAMSON American Physical Society, a member of the Geothough well versed in chemistry and in physics, he had that mathematical temperament which allowed him t o deal logical Society of Washington, and of the Washington Academy of Sciences, and one of the editors of the Academy’s journal. with the purely abstract side of a problem, and to reachits solution With the passing of Mr. Williamson a very real loss is suffered with an apparent ease and with an elegance which was always a by his colleagues. A brilliant scholar and a quick thinker, he source of wonder to his colleagues. His first published researches possessed the unusual faculty of applying his attainments t o the dealt with the solubility relations of the various forms of calcium solution of problems which required the cooperative effort of and magnesium carbonates. Later he became interested in the several investigators. His thorough knowledge of a wide range thermodynamics of solutions as applied t o equilibria in solutions, particularly a t high pressures, and was one of that unfortunately of subjects made collaboration with him both pleasant and rather small circle which understands and appreciates the work profitable, and his generous nature endeared him to all his asI,. H. ADAMS of Willard Gibbs. During the war he wasa member of a sociates.
