August 14, lOOSJ 



SCIENCE 



221 



7)1 hotc for tri-t' trc jii.'ililiftl in onfHiiiiiiKj llie 

 Eomogciicity of iho Chcmica} Kh-mriiisi B. B. 

 BowwooD. 



Tho Action of Light on Water of Onjstallixtition: 

 Ealpii H. jSIcKee and Elvin J. BisRKnEtsEu. 



J7io Estimation of Cerium in the Presence of tho 

 Other Rare Earths hy Potassium Fcrricyanido : 

 PiULir E. Browning and H. E. Palmer. 



The Pcrchlorates of Hydrasinc: A. W. Browne 



and J. W. TUKKENTINE. 



The Electrolysis of Anhydrons llydronitio Acid: 

 A. W. Browne and G. E. F. Lundell. 



On tho Question of tho Emstenco of Lead Suit- 

 ocaido: David Wilbur Horn. 



A System of Qualitative Analysis for the Com- 

 mon Elements. IV. Analysis of the Alkaline- 

 Earth and AVcali Croups: Wm. C. Brat. 



The Estimation of Vanadium hy Permanganato 

 after Ifeduetion hy Titanous Sulfate: II. A. 

 Newton. 



The Action of Bismuth O.Hdc on Reduced Sails 

 of Vanadium: H. A. Newton. 



Processes of Differential Oxidation and Reduc- 

 tion Applied to the Estimation of Vanadium, 

 Molyhdcnum and Iron: Graham Edgab. 



Determination of Arsenic in Inscetioides: D. L. 

 Randall and F. \V. Woodman. 



The Perchlorates of Uydraxine: A. W. Browne 

 and J. W. Turrentine. 



PHYSICAL chemistry 



Frank K. Cameron, Chairman 

 Liquid ahoce tho Critical Tempm-ature: W. P. 



Bradley, A. W. Browne and 0. F. Hale. 



TliB autlioi's, who adhere to tho view that liquid 

 does exist above the critical temperature, describe 

 a way in which that liquid can be " seen " in a 

 Cailletet apparatus while temporarily localized 

 by virtue of its greater specific gravity. It forms 

 ripples which flow down the walls of tho con- 

 tainer, adhering thereto, and accumulating imder 

 tho uuliqneficd vapor. Its top may be sliarply 

 bounded, though not, of course, by a meniscus. 

 The location of the boundary is marked by the 

 conduct of the ripples as they flow down upon it, 

 and also by that of similar ascending ripples 

 which may be caused by slight evaporation of tlio 

 liquid, brought about by appropriate incroam" of 

 volume. Tliese and other phenomena are contin- 

 uous above and below the critical temperature. 



The li'fhilioH Iniircvn thv TfuijicnUurc of Kero- 

 srne and the Explosion Pressure of the Super- 

 natant Mixture of Vapor and Air: W. P. 

 .liuADLEY and C. F. Hale. 

 Tho explosion pressure of tho vapor air mix- 

 ture of two typical samples of kerosene, conflned 

 at atmospheric pressure, were measured from tho 

 temperature at which explosion first occurred .to 

 that at whieli the mixtiire was too rich in vapor 

 to explode. Explosion was induced by the electric 

 spark. At tlie temperature of the Elliot (closed) 

 cu|) flash point tlic explosion pressure is already 

 one lialf (lie iiiaxinuuu pressure. At that of tho 

 Tagliabul (upon) cup flash point it is almost 

 equal (o the iniiximum, while in lliat of the 

 Tagliabul lire ]H)ii\t the mixture is rich, so that 

 tho explosion pressure is greatly reduced and tho 

 danger therefrom is practically over. 

 Nolo on tho Ilydrolytio Dissociation of 'Nilro- 

 hcnzcnc: K. R. Renshaw. 

 Attempts have been made to determine the 

 decomposition of nitrobenzene by water at dif- 

 ferent temperatures and concentrations by tlie 

 cohirinietrio estimation of tho nitrite formed. A 

 hunilrodth mohir solution is dissociated between 

 0.00;i and O.OO-I per cent, at 37°. li'quilibrium is 

 only readied after a nund)er of days. Tlio results 

 at higher temperatures in sealed tubes are of no 

 value on account of tho alkali dissolved from the 

 glass. This and similar reactions will he studied 

 by the conductivity method. 



Tho Specific Heals of the Elements: J. E. Mills. 

 The paper gives a critical snnunary of tho 

 data upon tho speciflc heats of tho elements and 

 points out tho following conclusions: (1) Tho 

 speciflc heats of tho elements change rapidly with 

 tho temperature, tho change being greatest at low 

 tomperaturo and for elements with low atomic 

 weight. (2) It is absolutely hopeless to claim 

 any sort of constancy for the product of tho 

 atomic weight of an element and its speciflc heat 

 at varying temperatures. (3) Tho value of tho 

 atomic heat at the absolute zero is not tho sanio 

 for all substances, but the substances with the 

 larger atomic weight have at that temperature 

 the largest atomic heat. (4) The total energy 

 of a molecule in tho liquid condition at its melt- 

 ing point, if 'its energy at 0° absolute bo con- 

 sidered zero, is approximately three times the 

 kinetic energy of tho same molecule were it a 

 gas at that temperature. (5) It is suggested 

 that the law of Dulong and Petit is only a 

 special case of an equation similar to the oqua- 

 liorv for gases, in which the molecular heat at 



