308 



SCIENCE. 



[N. S. Vol. XXI. No. 530. 



notes on the additions in various departments 

 and lists of tlie various lecture courses. 



SOCIETIES AND ACADEMIES. 



THE NEW YORK ACADEMY OF SCIENCES. SECTION 

 OF ASTRONOMY, PHYSICS AND CHEMISTRY. 



The regular monthly meeting of the section 

 was held at Fayerweather Hall, Columbia 

 University, on Monday evening, November 7, 

 with Professor Charles L. Poor in the chair. 

 Abstracts of the papers which were presented 

 before the section are as follows : 

 The Relation of Kathode Resistance to the 

 So-called Saturation Current in the Dis- 

 charge through Gases: P. L. Tufts. 

 In this paper it was pointed out that the 

 so-called saturation currents obtained by Wil- 

 son and other investigators of the phenomena 

 of electrical conduction through flame gases 

 were not true saturation currents, but only 

 apparently so, owing to the development at 

 the kathode of a high resistance when the 

 impressed electromotive forces were over a 

 few volts. By the use of a kathode coated 

 with calcium oxide and heated by a separate 

 flame it was shown that the resistance of a 

 flame connecting this with the anode remained 

 practically constant; that is, the current 

 through the connecting flame increased directly 

 as the potential gradient for gradients rang- 

 ing from a few tenths of a volt to the centi- 

 meter, up to gradients of as much as fifty 

 volts to the centimeter. 



Experiments were made with the ordinary 

 luminous gas flame as well as with flames 

 rendered non-luminous by the admixture of 

 air, and the relation between current and 

 potential gradient was found to be the same 

 for both kinds of flames. 



The Duration of the Afterglow Accompanying 

 the Electrodeless Discharge at Low Pres- 

 sures, Effect of Temperature : C. C. Trow- 

 bridge. 



The purpose of the investigation was to de- 

 termine the nature of the glow that often ap- 

 pears after the cessation of the electrodeless 

 discharge in gases at low pressures. Measure- 

 ments made thus far on the duration of the 

 glow in air show a sharp maximum of dura- 



tion between .1 and .05 millimeter pressures 

 and that this maximum point varies with the 

 electrical conditions of the experiment. It 

 was also determined that there is a critical 

 point between .7 and .3 millimeter pressures 

 where the glow is only occasionally formed, 

 after which as the pressure is further reduced, 

 the duration of the glow increases rapidly to 

 the maximum. The electrodeless discharge 

 was also made to take place at liquid air tem- 

 perature and it was found that the afterglow 

 accompanying the discharge was diminished 

 considerably in duration and intensity at the 

 low temperature of about — 186° C. 



The ofiicers of this section for 1905 were 

 then elected and are as follows : 



Chairman — Ernest R. van Nordroff. 

 Secretary — Charles C. Trowbridge. 



The next regular meeting of the section was 

 held on Monday, December 5, with Professor 

 William Hallock in the chair in the absence 

 of Professor Poor. 



The papers of the evening were as follows: 



The Combination of Ions with tlie Solvent in 



Solutions: C. W. Kanolt. 



The object of Dr. Kanolt's investiga- 

 tion was to determine whether or not the 

 ions of a salt in solution are combined with 

 the solvent. The method used was the elec- 

 trolysis of a salt dissolved in a mixture of 

 two solvents, with the subsecjuent analysis of 

 the portions of the solution around the two 

 electrodes. If the ions are combined with 

 either of the solvents, this solvent will be 

 carried from one electrode to the other, and 

 changes in the proportions of the two solvents 

 are to be expected. Positive results were ob- 

 tained with silver nitrate dissolved in a mix- 

 ture of pyridine and water, indicating that 

 pyridine was combined with the silver ions. 

 With the same salt in a mixture of alcohol 

 and water only negative results have so far 

 been obtained. Other salts are being in- 

 vestigated. 



Chemical Combination of Knall-gas under 

 the Action of Radium: Bergen Davis and 

 C. W. Edwards. 



The experiments described I'elate to the 

 chemical combination of hydrogen and oxygen 



