February 17, 1905.] 



SCIENCE. 



257 



already published {Journal of Physical 

 Chemistry, June, 1904, and December, 

 1904) and of work along the same line yet 

 to be published. An equation was de- 

 duced based upon the idea that the so-called 

 cohesive forces between the molecules of a 

 liquid could be entirely and quantitatively 

 accounted for on the supposition of an at- 

 tractive force between the molecules, the 

 force varying inversely as the square of 

 the distance apart of the molecules. The 

 deduced equation was tested by an ex- 

 amination of twenty-five liquids over wide 

 ranges of temperature and pressure. The 

 measurements used were, for the most part, 

 those made by Drs. Ramsay and Young 

 and Dr. Young. The result undoubtedly 

 allows the conclusion to be drawn that the 

 intramolecular forces obey a law exactly 

 similar to the law of gravitation, i. e., the 

 attraction between the molecules of any 

 liquid varies inversely as the square of the 

 distance apart of the molecules, does not 

 vary with the temperature, and is a func- 

 tion of the number of molecules (mass) 

 considered. 



The results also point to the conclusion 

 that the so-called molecular association, as 

 in the case of water, is caused by this same 

 molecular attraction and not by another 

 force such as chemical affinity. 



On Crompton's Equation for the Heat of 



Vaporization: J. E. Mills. 



An equation proposed by Mr. Crompton 

 {Proc. Chem. Soc. (London), Vol. 17, 

 1901), L = 2RT log e d/D (L is heat of 

 vaporization, E is the constant of the gas 

 equation, PV — RT, T is the absolute tem- 

 perature, d and D are the densities of 

 liquid and vapor, respectively) was ex- 

 amined. It was shown that the latent 

 heats so calculated were invariably and 

 usually very considerably too high at low 

 temperatures where the vapor pressure is 

 small, but at high press\;re, as the critical 

 temperature of the liquid is approached. 



the results are in excellent agreement with 

 the true heats of vaporization. Some im- 

 portant results following from this equa- 

 tion were pointed out. The article was 

 published in the Journal of Physical Chem- 

 istry, for December, 1904. 



AGRICULTURAL, SANITARY AND PHYSIOLOG- 

 ICAL CHEMISTRY. 



Wm. P. ]\Iason, chairman. 



interpretation of a 'W'^ater Examination^ : 

 Wm. p. Mason. 



The paper will be published in Science. 



The Water of Utah Lake: F. K. Cameron. 



In this paper comparisons are made of 

 analyses of Utah Lake water covering a 

 period of twenty years. It is shown that 

 the mineral content of the water is con- 

 tinually increasing, the water containing 

 about 300 parts of total solids in 1883 

 against over 1,400 parts per million of solu- 

 tion at the present time. This increase is 

 mainly due to sodium chloride introduced 

 by the seepage waters from the surround- 

 ing irrigated areas, which areas have been 

 brought under cultivation since the first 

 analyses were made ; second, by the diver- 

 sion, for irrigation purposes, of mountain 

 streams formerly entering the lake ; and 

 third, by the relatively large evaporation 

 from so shallow a body of water. 



Determination of Oxygen consumed in 

 Water Analysis: L. P. Kinnicutt. 

 The amount of oxygen consumed by a 

 given water depends on the method used 

 for determining this factor. Analyses of 

 many samples of water and sewage show 

 that the results obtained by the two Eng- 

 lish four hour methods, the 'English 

 official' and the 'Manchester,' agree very 

 closely with each other. 



The results obtained by the four modifi- 

 cations of Kubel's method, which are used 

 in this country, are not only very different 

 from the results obtained by the English 



