48
JOURNAL O F CHEMICAL EDUCATION
JANUAEY, 1931
Literature Cited ( 1 ) Lmavms. "Sur le muriate d'etain FumantouLiqueur delihavius," Ann. ckim., 1, 5 (1794). ( 2 ) DAVIS,"Priestley's Last Defense of Phlogiston," J. CHEM.EDUC.,4, 176-83
( ~ ~ b1 .9, ~ ) . (3) FOSTER,"Doctor Madean and the Doctrine of Phlogiston," ibid., 2, 743-7 (Sept., 1925). (4) HALL,"A Chemist of a Century Ago," ibid., 5, 250, 253-7 (Mar., 1928).
Radium Decay. Fears aroused by the experiments of one L. Bogojavlensky, indicating that the rate a t which radium and allied substances decay into other elements may he made t o change, have been allayed. For Madame Curie, who with her husband, Pierre, in 1902, discovered radium, has saidshe is unable t o find any evidence t o indicate that such change is possible. I n short, radium is goiog along decaying a t the same old rate, 1750 years for half a given quantity. It is the custom of scientists in expressing the disintegration of the elements of the radioactive series of umnium to speak in terms of the half period, or the time required for the disintegration of half a given amount. And in this respect it is interesting t o note that the time required for the change in the elements concerned varies from one-millionth of a second t o eternity. Out of the work of the distinguished English scientist, Soddv, one-time member of the staff of .\lrGill ilni\.rrsity in llontred, has comc understanding of tht dkintegration of the radioactive clrrnenrs. When, for instance, rddinm cmm hrliurn them is produced another gas, radium emanationor radon. The latter, radioactive in its own right, undergoes still further disintegration. So radium, i t seems, occupies an intermediate niche in a long series which begins with uranFum and ends with lead. The latest market quotation an radium is $65,000 a gram.-Tech. Reu., 32,362 (May, 1930)
Lithium. Quantity production of lithium in America seems assured. Lithium, it will be recalled, is a metal whose specific gravity is less than that of water; a chunk of i t dropped upon water will float like cork until i t disintegrates. Although recently produced commercially in Europe, i t is still very rare in this country and has been selling for more than $200 a pound. The new quantity production method developed by Dr. H. M. Partridge, assistant professor of chemistry a t New York University, made it possible t o place i t on the market in ton lots a t $15 a pound. Lithium is used in alloys and it loses its softness when combined with some other metals. It has been used to obtain a better tone in bells and its sponge-like absorption of gaseous impurities has made possible the increase of lifting power of helium gas by some fifteen oer cent. The American product, according to Dr. W. C. MacTsvisb, who announced i& development a t the ~ e w ~ o Electrical r k Society, is much purer than the German, although its production is based upon German patents plus methods devised by the University of New Hampshire five years ago by the late Professor Charles James and Dr. McTavish.-Tech. Rev., 32, 147 (Jan., 1930)
