CHEMISTRY. 



383 



of hydrocarbons from thermo-cliemical investigations. For tlie fatty 

 series the structure generally adopted is regarded as correct. But in 

 the aromatic series, he concludes against the constitution as expressed 

 by Kekule's formula, and says : "The six carbon atoms of benzene are 

 niiited to each other by nine single bonds; and the previous assumption 

 of a structure of benzene with three single and three double bonds, is 

 not supported by experiment. {Ber. Befl. Chem. Ges., January, 1881, 

 xiii, 1321, 1388, 1806; Am. J. Sci. February, 1881, III, xxi, 87.) 



Thomsen has endeavored to show that the molecular rotation {i. e., 

 the i^roduct of the rotatory power by the molecular weight divided by 

 100,) is for many classes of bodies a simple multiple of a constant num- 

 ber. This constant for a large class of bodies is 0.95 ; this multiplied 

 by 4 gives 3.8, the constant for the family of alcohols, and by 9 gives 

 8.05 the amide family constant. {Ber. Berl. Clicm. Ges,, January, 1881, 

 xiii, 2168, 2264, 2266, 2269.) 



Briihl has advanced the hypothesis that the molecular refraction of 

 isomeric carbon compounds is constant only when they contain singly- 

 linked carbon atoms, and hence variations in this constant must be due 

 to variations in the manner of linking. Janowsky, however, has main- 

 tained that slight differences are always noticeable between the mo- 

 lecular refractions of isomeric compounds where the grouping of the 

 carbon atoms and not the linking is the cause of the isomerism. {Ber. 

 Berl. Chem. Ges., January, 1881, xiii, 1520, 2415; Nature, February, 1881, 

 xxiii, 374.) 



INORGANIC. 



Yalente has shown the replacement of iodine by chlorine in a strik- 

 ing form for a lecture experiment, as follows : A jar of 500 cubic centi- 

 meters capacity is filled with dry hydrogen iodide gas, and another of 

 250 cubic centimeters capacity with dry chlorine, the larger jar being 

 I)laced above the other, with a glass plate between them. On with- 

 drawing the i:)late decomposition occurs with a flash of rose-colored 

 flame, and iodine is deposited. {Nature, July, 1881, xxiv, 293.) 



Allary and Pellieux have proposed to evaporate to dryness the mother 

 liquors used for the preparation of iodine, to roast, to extract with cold 

 water and again evaporate, to extract the residue with alcohol, to distill 

 oft" the alcohol, to add potassium carbonate, to pass carbon dioxide gas 

 through the solution, and to crystallize out pure potassium iodide. {Bull. 

 Soc. Chim., II, xxxiv, 627; Am. J. Sci., February, 1881, III, xxi, 136.) 



Hautefeuille and Chappuis have observed that when oxygen is con- 

 verted into ozone by the silent discharge, a low temperature greatly 

 augments the yield. Thus at 760 millimeters a temperature of — 23° gave 

 0.214 by weight of ozone, and at 180 millimeters pressure 0.181. Mixed 

 with four vols, of nitrogen at this temperature, the ozone was increased 

 to 0.216, and to 0.240 when two vols. X. were present. On cooling the 

 ozone by methyl-chloride, and compressing it in a Cailletet's apparatus, 

 an azure-blue color api)eared in the tube, becoming indigo-blue at sev- 



