40 Chemistry and Physics 



given temperature, and for the temperature coefficients of conductivity, it is fre 

 quently difficult to find what is desired ; or, if found, the data may be so discordant 

 that it is impossible to decide as to the true conductivities and dissociations in 

 question. Since ^he magnitude of the dissociation of any electrolyte is fundamental 

 to its scientific use in chemistry, it is desirable that such data should be made avail- 

 able over the range of temperature most frequently used in the laboratory. With 

 this idea in mind, the work has now been continued until it represents more than 

 twenty years' continuous labor for one man, about 40,000 conductivity measurements 

 having been made. The conductivities and dissociations of about 110 of the more 

 common salts have been worked out from zero to 65 degrees, and over a range in 

 dilution extending from about the most concentrated solution that could be used to 

 the dilution of complete dissociation. The temperature coefficients of conductivity 

 have been calculated in both conductivity units and per cent. Similar data have been 

 obtained for about 90 of the more common organic acids, and their constants have 

 been calculated by means of the Ostwald dilution law. 



No. 180. JONES, HARRY C, assisted by C. M. STINE, J. N. PEARCE, H. R. KREIDER, 

 E. G. MAHIN, M. R. SCHMIDT, J. SAM. GUY, and P. B. DAVIS. The 

 Freesing-Point Lowering, Conductivity, and Viscosity of Solutions of 

 Certain Electrolytes in Water, Methyl Alcohol, Ethyl Alcohol, Acetone, 

 and Glycerol, and in Mixtures of these Solvents zvith one another. 

 Octavo, vii+214 pages, 85 text figures. Published 1913. Price $2.00. 



The seven pieces of work incorporated in this monograph are a continuation of 

 the investigations recorded in monograph No. 80. The effect of one hydrated salt 

 on the hydration of another hydrated salt was worked out with a number of pairs 

 of salts. The dissociation of a number of salts was determined by the freezing- 

 point and conductivity methods. It was shown that the atoms or ions with the 

 smallest volumes have the greatest hydrating power. The relation between hydrat- 

 ing power and electrical density is discussed. The dissociation in the alcohols was 

 determined by the improved conductivity method. 



Three investigations had to do with the physical chemistry of glycerol as a 

 solvent The conductivity and viscosity of solutions in glycerol as a solvent were 

 studied at different temperatures, glycerol being a liquid solvent with enormous vis- 

 cosity. The temperature coefficients of both conductivity and viscosity in glycerol 

 were very great. The salts of ammonium and rubidium were found to lower the 

 viscosity of glycerol. 



No. 190. JONES, HARRY C, and J. S. GUY. The Absorption Spectra of Solutions 

 as Affected by Temperature and by Dilution: A Quantitative Study of 

 Absorption Spectra by Means of the Radiomicrometer. Octavo, 

 vii+93 pages, 22 plates, 44 text figures. Published 1913. Price $2.00. 



A form of closed apparatus was devised and used for studying the absorption 

 spectra of aqueous solutions up to 200. It was found that the absorption bands 

 widen with rise in temperature. The effect of dilution on the absorption spectra of 

 solutions was also investigated over a range of dilution varying from 1 to 500. The 

 absorption increased with the concentration, especially towards the red end of the 

 spectrum. A radiomicrometer was built and used for studying absorption spec- 

 tra quantitatively. This permitted work at much greater wave-lengths than was pos- 

 sible by means of the grating spectroscope and photographic plate. The former was 

 limited to X 7,600, while the latter can be used as far as X 30,000, and even farther. 

 The effect of dilution was also studied quantitatively by means of the radiomicrom- 

 eter, and interesting and important results were obtained in reference to the effect 

 of dilution on the nature and position of the transmission bands. It was found that 

 "free" water had a different absorption from "combined," and this was regarded as 

 further evidence for the solvate theory of solution. The absorption spectra of a 

 fairly large number of salts were mapped by means of the radiomicrometer. 



