698 



SCIENCE. 



[N. S. Vol. XIX. No. 487. 



cusses and figures ' Arcterica, the Rarest 

 Genus of Heathers,' living on Bering Island. 

 W. F. Ganong has begun a series of descrip- 

 tions of ' New Precision-appliances for Use 

 in Plant Physiology,' this first paper dealing 

 with a clinostat and a portable clamp stand. 



SOCIETIES AND ACADEMIES. 



THE NATIONAL ACADEMY OF SCIENCES. 



The following papers were presented at the 

 spring session held at Washington on April 

 19, 20 and 21. 



E. L. Nichols and Ernest Mereitt : ' On 

 Fluorescence Spectra.' 



John Trowbridge : ' Spectra of Gas at High 

 Temperatures.' 



Theodore Lyman, presented by John Trow- 

 bridge : ' Short Wave-Lengths of Light.' 



H. W. Morse, presented by John Trowbridge: 

 ' Spectra produced by the Wehnelt Interrupter.' 



George F. Barker: 'Note on Eadioactivitj' and 

 Autohiminescence.' 



R. S. Woodward : ' A Double Suspension Ap- 

 paratus for determining the Acceleration of 

 Gravity.' 



R. S. Woodward : ' The Compressibility of the 

 Earth's Mass required by the Laplacian Law of 

 Density Distribution.' 



Henry L. Abbot : ' The Disposition of Rainfall 

 in the Basin of the Chagres.' 



A. F. Zahm, introduced by A. Graham Bell: 

 ' Surface Friction of the Air at Speeds below 40 

 Feet a Second.' 



R. H. Chittenden : ' Physiological Economy in 

 Nutrition, with Special Reference to the Minimal 

 Proteid Requirement of the Healthy Man.' A pre- 

 liminary Report. 



Henry F. Osborn : ' Recent Paleontological Dis- 

 coveries by the American Museum Exploring 

 Parties.' 



Henry F. Osborn : ' Reclassification of the 

 Reptilia.' 



W. D. Matthew, submitted by Henry F. Os- 

 born : ' Position of the Limbs in the Sauropoda.' 



Horatio C. Wood, Jr., presented by Horatio C. 

 Wood : ' A Preliminary Report upon Apocynum 

 cannahinum.' 



Arthur T. Hadlet, presented by the Home 

 Secretary : ' Biographical Memoir of James Had- 

 ley.' 



Charles L. Jackson : ' Biographical Memoir of 

 Henry Barker Hill.' 



Alexander Graham Bell: ' The Multi-nippled 

 Sheep of Beinn Bhreagh.' 



Simon Newcomb : ' Application of New Sta- 

 tistical Methods to the (Question of the Causes 

 Influencing Sex.' 



C. S. Peirce: 'Note on the Simplest Possible 

 Branch of Mathematics.' 



THE AMERICAN CHEMICAL SOCIETY. 

 NEW YORK SECTION. 



The seventh meeting of the season was held 

 April 8, at the Chemists' Club, 108 West 

 Fifty-fifth Street. The following program 

 was presented: 



The Determination of Manganese as Sulphide 



and the Composition of the PinTc and Green 



Sulphides: J. C. Olsen. 



Professor Olsen discussed the advantages 

 of separating and determining manganese as 

 sulphide. The method is only practicable, 

 however, when the sulphide is obtained as the 

 green modification which is larger grained 

 than the ordinary pink sulphide and, there^ 

 fore, settles more readily and is more easily 

 filtered and washed. This is best accom- 

 plished by pouring the manganese solution 

 into a boiling solution of ammonium chloride 

 and ammonium sulphide. 



On analysis the pink sulphide showed vari- 

 able amounts of water. This was found to 

 be due to the fact that it is a mixture of a 

 gray sulphide which holds more than three 

 per cent, of water and a red sulphide. This 

 modification was obtained pure and was found 

 to hold the same amount of water as the green 

 sulphide, about three fourths per cent. The 

 difference between the pink and green sul- 

 phide is held to be one of molecular structure, 

 rather than of chemical composition or de- 

 gree of hydration. 



On the Comiination of a Solvent with the 

 Ions (preliminary paper) : J. Li\'ingston E. 

 Morgan and C. W. EIanolt. 

 Preliminary experiments were reported 

 which show that by electrolyzing a solution 

 of silver nitrate and pyridine in water, pyri- 

 dine migrates with the silver and increases in 

 concentration at the cathode, while it de- 

 creases at the anode. With cupric nitrate 

 and water, dissolved in alcohol, water mi- 

 grates with the copper ions and increases on 

 the cathode and decreases at the cathode. 



