Chemistry and Physics. 193 



which most of our knowledge is due to McCay and his pupils at 

 Princeton University, viz., 



H 3 As0 3 S, 

 H 3 As0 2 S 2 , and, 

 H 3 AsOS 3 , 



These sulphoxy acids have not been isolated, and only the first 

 two appear to exist in dilute solutions. 



The trisulphoxyarsenates are usually colorless, crystalline, rather 

 unstable compounds. The sodium salt is prepared by acting in 

 the first place upon arsenic pentasulphide with a large excess of 

 magnesium oxide in the presence of water, whereby the sulphide 

 dissolves ; then precipitating magnesium hydroxide by means of 

 sodium hydroxide and removing it by filtration, adding alcohol to 

 the liquid until a turbidity begins to form, and finally cooling to 

 crystallization. — Zeitschr. anorgan. Chem. xli, 452. h. l. w. 



5. The Electrolysis of Solid Electrolytes. — It has been found 

 possible by Haber and Tolloczko to electrolyze solid barium 

 chloride at a temperature about 400° below its melting-point. 

 When barium carbonate had been mixed and fused with the 

 barium chloride, carbon was produced at the cathode in quantities 

 corresponding to the electric current employed, but when the 

 barium chloride was free from carbonate, barous chloride formed 

 quantitatively. In both cases the result may be assumed to be 

 due to the reaction of metallic barium with the substances pres- 

 ent. The experiments were conducted in nickel crucibles with care- 

 ful regulation and measurement of the temperatures. Attempts to 

 electrolyze sodium hydroxide were not successful when the sub- 

 stance was perfectly solid. — Zeitschr. anorg. Chem., xli, 405. 



U. L. VV. 



6. The Determination of Fluorine in Wine and Beer. — On 

 account of the frequent use of sodium fluoride as a preservative, 

 particularly for French, Spanish, and Greek sweet wines, and 

 because of the poisonous effect of this preservative, which appears 

 to have been established by the results of several investigators, 

 Treadwell and Koch have undertaken the examination of vari- 

 ous methods which appeared applicable to the determination 

 under consideration. 



No easy method for performing this difficult determination was 

 found, but interesting results in regard to the accuracy of the 

 standard methods, and the limits within which fluorine can be 

 detected qualitatively, were obtained. A slightly modified appa- 

 ratus for the determination according to Penfield's method is 

 described and figured. —Zeitschr. analyt. Chem., xliii, 469. 



H. L. W. 



7. Direction and Velocity of Electric Discharges in Vacuum 

 Tubes. — Wheatstone in 1835, by means of a rotating mirror, 

 arrived at the conclusion that this velocity was not less than 

 8 x 10 7 cm. per second ; Plticker from observations in a magnetic 

 field, concluded that the discharge emanated from the positive elec- 



