August 24, 1906.] 



SCIENCE. 



239 



INORGANIC CHEMISTRY. 



L. M. Dennis, Chairman. 



Some New Compounds of Thallium: L. F. 



Hawley. 



Three new compounds of thallium were 

 described: thallium fulminate, TI2C2N2O2, 

 thallium aluminate, TI4AI2O5 . 2H2O, and 

 potassium thallic chromate, KgCrO^ . TI2 

 (CrOj3.4H20. 



Experiments upon the Radium Emanation: 



L. F. Hawley. 



With the idea in view that the rare at- 

 mospheric gases might be the activizing 

 agents of radioactive bodies an attempt was 

 made to find whether the atmosphere pro- 

 duced any effect on the emanations from 

 radium. A water solution of radium chlo- 

 ride was kept in an atmosphere of hydro- 

 gen entirely free from the atmospheric 

 gases, and the emanations produced during 

 several three-day periods were measured 

 by bubbling the pure hydrogen through the 

 solution and leading the hydrogen and 

 emanation into a measuring tube connected 

 with an electrometer. Then similar meas- 

 urements were made under exactly the 

 same conditions except that air was used in 

 the place of the hydrogen. No difference 

 was found except that due to the difference 

 in the absorption of the radiations by the 

 hydrogen and the air. 



On the Reaction between Hydrazine Sul- 

 phate and Potassium Chlorate: A. "VV. 

 Browne. 



This reaction does not proceed in pres- 

 ence of sulphuric acid entirely in accord- 

 ance with the general equation for the 

 oxidation of hydrazine sulphate as given 

 by Roberto and Roncali : 



N,H4 . H^SOi + 20 = N„ + 2H2O + H0SO4. 



Three series of experiments have been 

 made, from which it is evident that the 

 reaction takes place very largely as ex- 

 pressed by the following equation: 



4N2H^ . H,S04 + 40 



=2HN3 + (NH,) .SO* + 3H,S0, -f 4H2O. 



Within certain limits the yield of HN3 

 varies directly with the amount of H2SO4 

 present and inversely with the excess of 

 KCIO3. Under favorable conditions the 

 yield amounts to over 23 per cent, of theory 

 according to the above equation. 



A Modified Hydrogen Sulphide Generator: 

 A. W. Browne and M. F. Mehling. 

 The apparatus is essentially a modified 

 Ostwald gas generator capable of furnish- 

 ing hydrogen sulphide in quantities suffi- 

 cient to supply a class of 275 students. 

 The supply of acid (1:1 HCl) and the dis- 

 charge of the thoroughly neutralized spent 

 acid is automatically regulated by a method 

 somewhat similar in principle to that em- 

 ployed in the Parsons apparatus. 



On the Analysis of Silver Trinitride: L. 

 M. Dennis and A. W. Browne. (By 

 title.) ^,^i 



Colorimetric Determination of Iron with 

 special reference to Purity of Reagents: 

 H. N. Stokes and J. R. Cain. 

 The interfering action of large amounts 

 of acids or salts is avoided by concentrating 

 the iron, either by evaporation in the case 

 of easily volatile substances or by carrying 

 down as hydroxide by manganese dioxide 

 (reduced from permanganate) or as sul- 

 phide by cadmium sulphide. After suit- 

 able treatment it is dissolved in free sul- 

 phocyanic acid saturated with mercuric 

 sulphocyanate, and after adding a little 

 persulphate is extracted with amyl alcohol 

 in the colorimeter cylinder, the duplicate 

 cylinder containing the same volume of sul- 

 phocyanic acid and amyl alcohol. Less 

 than 0.001 mg. iron may thus be detected 

 in 50 grams of a non-volatile salt. 



Beryllium Carbonate: Charles L. Parsons 

 and Edwin J. Roberts. 

 Normal beryllium carbonate can not be 



