162 



SCIENCE 



[N. S. Vol. LII. No. 1337 



Spontaneous evaporation: Harry B. Weisee and 

 Everett E. Porter. 



Negative surface energy: William D. Harkins 

 and Y. C. Cheng. 



The formation of ammonia from nitrogen and 

 hydrogen in the corona: William D. Harkins and 

 A. Morton. 



The electrical conductivity of dilute aqueous so- 

 lutions of the alkali hydroxides : Merle Randall 

 and C. C. Scalions. 



The partial molal volume of the constituents in 

 solutions of electrolytes: Merle Eandall. 



A revision of the atomic weight of antimony. 

 Preliminary report : H. H. Willard and E. K. Mc- 

 Alpine. 



A separation and volumetric determination of co- 

 talt: H. H. Willard and Dorothy Hall. 

 A new form of filtering crucible: H. H. Willard. 

 Notes on tlie determinaition of chromium as 

 chromic oxide: Wm. H. Blanchakd. 



The preparation of colloidal selenium : Victor E. 

 Levine. 



A theory of catalytic action: Chas. W. CtjNo. 

 Sadiation and chemical reactivity: Eric K. 

 Eideal. The radiation theory of chemical physi- 

 cal action as developed by Trausy MarceUn Price 

 and more recently by Mc. Lewis, Bernouilli and 

 Perrin, in the light of the Eutherford Bohr atomic 

 structure offers a tangible interpretation for the 

 mechanism of chemical and physical change; cal- 

 culation from radiation data leads to results for 

 the latent heats of evaporation; electrode poten- 

 tials and heats of reaction of various elements and 

 compounds in close agreement with experimental 

 results. Catalytic action on the radiation theory 

 admits of various interpretations as to the possible 

 modes of mechanism; these are briefly described 

 and answered. 



Quantitative measurement of fluorescence : L. J. 

 Desha. The radiation from a mercury arc in 

 quartz tube, separated from most of the visible 

 rays by a glass screen of the "XJviol" type, is al- 

 lowed to fall upon solutions contained in the cups 

 of the Kober nephelometer. Fluorescent sub- 

 stances emit light which may be compared in the 

 eye piece as in nephelometry. Solutions contain- 

 ing one half to two parts of quinine sulphate per 

 million in normal sulphuric acid yield readily com- 

 parable results which are almost if not quite di- 

 rectly proportional to the concentrations. Appli- 

 cations as an analytical procedure are suggested. 

 The work is being continued. 



Some applications of sodium peroxide in an- 

 alytical chemistry: W. M. Sternberg. Some ap- 

 plications of sodium peroxide to analytical proc- 

 esses in particular fusions of lead and zinc ores in 

 iron crucibles have been studied. The decomposi- 

 tion is very rapid and complete in every case. 

 When the usual proportion of sodium peroxide to 

 ore (5 to 8 times the weight of the ore) has been 

 used. If" smaller amounts of the peroxide be taken 

 the reaction in case of sulphide ores is rather vio- 

 lent. The results in case of lead ores were uniform 

 but low unless the standard solution has been 

 standardized against a standard ore run by the fu- 

 sion method. The procedure consisted in fusion one 

 half gram ore in an iron crucible with about 3 to 

 4 grams of sodium peroxide, dissolving the melt in 

 water, adding 0.7 gram oxalic acid to reduce the 

 lead peroxide. The solution was acidified with 

 sulphuric acid boiled, cooled, lead sulphate filtered 

 and washed with 5 per cent, sulphuric acid. The 

 impure lead sulphate was dissolved in ammonium 

 chloride, or ammonium chloride-sodium acetate mix- 

 ture, heated to boiling and titrated with ammonium 

 molybdate. In the case of zinc ores the peroxide 

 fusion was dissolved in ammoniacal ammonium 

 chloride solution heated to boiling, filtered and 

 washed with hot ammonium chloride solution, 

 acidified with hydrochloric acid, heated to boiling 

 and titrated with potassium ferrocyanide, after 

 the addition of 50 c.c. of hydrogen sulphide water. 

 Here also good results have been obtained if the 

 solution has been standardized against the stand- 

 ard zinc ore D, or against zinc oxide, both fused 

 and treated in the way described. 



Charles L. Parsons, 



Secretary 



SCIENCE 



A Weekly Journal devoted to the Advancement of 

 Science, publishing the official notices and pro- 

 ceedings of the American Association for 

 the Advancement of Science 



Published every Friday by 



THE SCIENCE PRESS 



LANCASTER, PA. GARRISON, N. Y. 



NEW YORK, N. Y. 



Enteied in the poel-effice at Lancmilct, Pa., ai Kcond clan matlci 



