VOL.3, NO. 8
PoTENTIOMETRK! TITRATIONS
841
BIBLIOGRAPHY Behrend, R.,"Elektrometrische Analyse," Z. physik. Chem., 11, 466 (1893). Battger, W., "Die Anwendung des Elektrometers als Indikator beim Titrieren von SAuren nnd Basen," Z. .ghysik. Chem., 24, 253 (1887). Crcrtug'no, I:., "Studicn uhcr Oxydationcpotmti.~Ie,"%.anorg. C h m ,24,1'?5 (1900). Forbes. (>. S., 2nd Bartlett, E.P., "Incrrarr in Oridltion Potential of 1)irhromate Ion on Platinum. Titration of Ferrous Salts," I. A m . Chem. Soc., 35, 1527 (1813). Hildehrand, J. H., "The Use of the Hydrogen Electrode in Analysis, Teaching, and Research," I. A m . Chem. Soc., 35, 869 (1913). The technic of the potentiometric method, and the extensive literature of the subject are given in the following teats: Clark, W. M., "The Determination of Hydrogen Ions," 2nd ed., Williams and Wilkins Co., Baltimore, Md. Furman, N. Howell, "Chapter XI11 of Taylor's Treatise on Physical Chemistry;' D. Van Nostrand & Co., New York, 1924. Kalthoff, I. M., and Furman, N. Howell, "Potentiometric Titrations, A Theoretical and Practical Treatise," 350 pp., John Wiley & Sons, Inc , New York, 1926. Miiller, E., "Elektrometrische Massanalyse," Theodor Steinkopf, Dresden, 3rd ed. ~
Iodine, Favorite Antiseptic, Now Has Rival in Neglected Chemical. Iodine, far many years a favorite first-aid antiseptic for bruises and cuts, is now having its preeminence challenged by potassium permanganate, a compound long known t o scientists hut hithertolittle used by people in general. Its advocates point out certain advantages it has over iodine, which they claim will eventually cause it t o replace the older drug. In the first place, they s'tate, it is not poisonous as,iodine is and, therefore, not so dangerous t o inquisitive children. Furthermore, it does not smart and bum when applied and an overdose will not cause harm to the flesh. I t is also pointed out that in the dry state potassium permanganate keeps indefinitely, whereas iodine deteriorates in time. For ordinary treatment half a teaspoonful of potassium permanganate crystals in a cup of water is sufficient, hut for ivy poisoning a teaspoonful to a cup is recommended. For very severe poisoning, such as snake bite, the dry crystals are pressed directly into the wound, or into small knife incisions about it.-Science Service Radio Hits Shellac Industry. With the radio replacing the phonograph in almost every home the shellac shipments from India into this country are only half what they used to he two years ago. At least half of the shellac used in the United States, which is one of the biggest importers of this necessary constituent of varnish, formerly went into the manufacture of phonograph records, according to a report to the American Chemical Society. In consequence the shellac producers of India, or rather the human powers who have control of the sticky gum deposited on the twigs of trees by the lac insects, have become panicky. They likewise remember the decline and fall of the indigo industry when synthetic indigo was finally produced in the laboratory. Anxious t o forestall a similar fate for natural shellac they have attempted t o safeguard themselves by getting in on the ground floor of the synthetic stuff in establishing a Lac Research Institute which has as an additional aim the improvement of the quality aod output of their product.-Science Senrice
