4:66 Scientific Intelligence. 



quite constant, but higher, in the vicinity of 30 to 32. Since we 

 have then a value for dissociation that is decidedly higher than 

 that for vaporization, Le Chatelier's law appears no longer to be 

 a generalization of Trouton's, but merely an analogous law. 



Having presented this matter as abstracted above, de Foitc- 

 and advances the belief that Le Chatelier's idea that the same 

 statement applies without exception to all phenomena of vapori- 

 zation, allotropic transformation and dissociation, ought to be 

 retained in science, and we should have 



L_L 1 _Q _Q L 



but that the statement of the law and the value of L should be 

 slightly modified. 



In Trouton's formula, L is the heat of liquefaction of any gas ; 

 in Le Chatelier's, Q comprises three terms, L heat of liquefaction 

 of a gaseous molecule, S heat of solidification of this liquid mole- 

 cule, q heat of combination of this solid molecule with a solid 

 body to form a solid compound without change of physical con- 

 dition, or, in other words, supplementary heat of solidification. 



The two terms = and — ^ — - are evidently not comparable, but 



they become so, and the values of the two will be almost con- 

 stant at about 30, if we add in the first a term S representing the 

 heat of solidification. We have then for all bodies, 

 L + S _ L + S + g 



Fin rrv ? 



where q is always positive and T' always greater than T. The 

 general law may be expressed as follows: "In all physical or 

 chemical phenomena, the heat of solidification of any gas is pro- 

 portional to its temperature of vaporization under atmospheric 

 pressure." — C. R., cxxxii, 879. h. l. w. 



8. Diewissenschaftlichen Grundlagen der analytischen Chemie, 

 von W. Ostwald. Dritte vermehrte Auflage. 8vo, pp. xii, 221. 

 Leipsic, 1901 (Wilhelm Engelmann). — The influence that this 

 book has exerted in causing the ionic theory to be accepted and 

 practically applied by chemists generally has been very great, 

 and the service that it has rendered to teachers and students of 

 analytical chemistry, in explaining many facts that were well 

 recognized but not understood, has been of the greatest impor- 

 tance. This third edition of the book in an enlarged and improved 

 form, appearing within seven years after the first issue, is heart- 

 ily welcomed. h. l. w. 



9. Spectrum of Carbon Compounds. — In view of the possible 

 appearance of a new comet the paper of Professor A. Smithells 

 on the carbon spectra is of great interest. He discusses the spec- 

 tra of cyanogen, of carbon disulphide, and the Swan spectrum, and 

 points out the danger of drawing conclusions from spectra 

 appearing in exhausted glass vessels which are due to contami- 

 nations from the constituents of the vessels. — Phil. Mag., April 

 1901, pp. 476-503. J. t. 



