578 



SCIENCE 



[N. S. Vol. LIII. No. 1382 



minishes very rapidly, but may not become zero 

 before 3,000 hours at room temperature. With 

 HCoHsOj the initial rate^fe'C H, but with mod- 

 erate values of C HCl this proportion becomes 

 inverse. Many other regrularities, likewise afford- 

 ing clues to the reaction mechanism, have been 

 noted. 



The volumetric oxidation of sulfide to sulfate: H. 

 H. WiLLARD and W. E. Cake. The alkaline sul- 

 fide solution obtained by absorbing HjS in NaOH 

 is oxidized quantitatively to sulfate if excess of 

 standard hypobromite or hypochlorite is added, 

 and sufficient hydroxide is present. The excess 

 is then determined by adding KI, acidifying, then 

 titrating the iodine with thiosulfate. The method 

 may be applied also to freshly precipitated sulfides, 

 such as ZnS. Since four times as much oxygen 

 is required in this reaction as in the usual iodine 

 titration, the method is especially suitable for 

 small amounts of sulfur. 



MaTcing scientists: Eecovering the normal curi- 

 osity in college students: Edward Ellery. A 

 normal boy and the investigating scientist have 

 this in conunon — they are both living interrogation 

 points. The investigator minus a "why" is an 

 anomaly, and a boy without it is abnormal, if not 

 defective. If college training knocks the natural 

 "why" out of a boy, a reform can not too soon 

 be instituted. Here is the way Union College is 

 working to effect such a reform. At every oppor- 

 tunity work is required that takes the boy away 

 from his textbook and laboratory manual and into 

 the library for consultation of larger treatises and 

 current periodicals. In the summer months, at 

 the end of the junior year, a few of the best stu- 

 dents receive appointments to the research labora- 

 tory of the General Electric Company, where they 

 handle a piece of research work under the direct 

 supervision of the leading members of the staff 

 of that organization. In their last year in col- 

 lege, their time in the chemical laboratory is given 

 to a continuation of this research work, or to a 

 new problem. It is only the unconquerably dull 

 boy that fails to react to this effort to awaken his 

 natural "why." 



The apparent irreversibility of the calomel elec- 

 trode: A. W. Laubengayer. When mercury is 

 made anode in a chloride solution a high-resistance, 

 black film forms over the surface of the mercury. 

 This is composed of drops of mercury and particles 

 of mercurous chloride. ' It is not known why mer- 

 curous chloride should be adsorbed so closely and 

 mercurous sulphate not. 



The theory of hydrogen overvoltage: D. A. 

 MacInnes and W. R. Hainswoeth. Experiments 

 on the effect of pressure on hydrogen overvoltage 

 show that the variation produced is in the direction 

 predicted by the theory advanced by MacInnes and 

 Alden ; i.e., the overvoltage increases when the pres- 

 sure is decreased. On the other hand, computation 

 of the overvoltage from the size of evolved bubbles 

 fails for layer potential^, since the phenomena at 

 metal surfaces get farther and farther away from 

 equilibrium conditions as higher overvoltages are 

 reached. However, the fundamental assumption 

 that overvoltage is an extreme case of concentra- 

 tion polarization, retains its usefulness in explain- 

 ing the experimental results, at least for the 

 lower potentials. 



The hydrogen electrode under high pressures: 

 W. E. Hainsworth. The variation of the E. M. 

 P. of the cell, H.lHCl (C.ln-HCl), HgO/Hg, with 

 pressure has been measured from one to 400 at- 

 mospheres. It was found that thermodynamic cal- 

 culations involving (1) the deviation of hydrogen 

 from a perfect gas, (2) the partial molal volume 

 of HCl in 0.1 NHCl, (3) the molal volumes of 

 mercury and calomel, and (4) the change of HCl 

 concentration with the compressibility of the solu- 

 tion, served to reproduce the observed potential 

 of the cell within 0.2 mv. throughout the pressure 

 range studied. This leads to the conclusions, (a) 

 that the "thermodynamic environment" is not 

 appreciably changed by the molecular hydrogen in 

 solution, or by compression, and (6) that the 

 fugacity (or effective pressure) of hydrogen can 

 be calculated up to 400 atmospheres from the 

 equation of state developed by Keyes. 



Potassium ammonoaluminate and ammonoma/n- 

 ganite: Trancis W. Bergstrom. The author has 

 added an ammonoaluminate and an ammonoman- 

 ganite of potassium to Franklin's list of salts 

 formed by the action of potassium amide, in liquid 

 ammonia solution, on the amides, imides or nitrides 

 of other metals. The aluminate has been pre- 

 pared by the action of a solution of potassium 

 amide on amalgamated metallic aluminium. Its 

 composition is represented by the formula 

 Al(NHK) (NHo):. Potassium ammonomanganite 

 has been obtained in the form of rose colored 

 crystals by the action of an excess of potassium 

 amide on manganese thiocyanate in accordance 

 with the reaction represented by the equation 



Mn(SCN), + 4KNH, 



:Mn(NHK),.2NH3 + 2KSCN. 



