Chemistry and Physics 39 



No. 130. JONES, HARRY C, and W. W. STRONG. A Study of the Absorption 

 Spectra of Solutions of Certain Salts of Potassium, Cobalt, Nickel, 

 Copper, Chromium, Erbium, Praseodymium, Neodymium, and Uranium 

 as affected by Chemical Agents and by Temperature. Octavo, ix-j-159 

 pages, 98 plates. Published 1910. In cloth binding. Price $5.00. 



This is a continuation of the work described in Publications Nos. 60 and 110. 

 The results obtained from the study of about 3,000 solutions are herein recorded. 



The effect of the addition of free acids and foreign salts on absorption spectra 

 show that chemical reactions are probably much more complex than we usually 

 suppose. It was found that solvents which do not absorb visible light may have 

 a marked influence on the absorption of the dissolved substance. Definite solvent 

 bands have been discovered for water, the alcohols, acetone, and glycerol. These 

 bands are characteristic of each solvent, and the proof of their existence is regarded 

 as strong evidence for the theory of solvation in solution. It is difficult, not to say 

 impossible, to see how the solvent can produce such a marked effect upon the reso- 

 nance of the vibrators in solutions unless it enters into some kind of combination 

 with the dissolved substance. The evidence for the solvate theory having become 

 so strong, a brief discussion of the significance of that theory is given. It is shown 

 that when we supplement the theory of electrolytic dissociation by the theory of 

 solvation we have a satisfactory theory of solution. 



A fairly large amount of work was done on the effect of temperature on the 

 absorption spectra of solutions, and the results are recorded. A bibliography of 

 the publications from this laboratory on the solvate theory of solution is appended. 



No. 160. JONES, HARRY C, and W. W. STRONG. The Absorption Spectra of So- 

 lutions of Comparatively Rare Salts, including those of Gadolinium, 

 Dysprosium, and Samarium; the Spectrophotography of Certain Chem- 

 ical Reactions, and the Effect of High Temperature on the Absorption 

 Spectra of Non-aqueous Solutions. Octavo, vm-|-112 pages, 67 plates. 

 Published 1911. In cloth binding. Price $4.00. 



The results of the study of three problems are herein recorded, and the ab- 

 sorption spectra of a number of rare substances are mapped. Salts of dysprosium 

 and samarium have spectra that are almost as interesting as those of neodymium. 

 The spectra of a number of salts in a large number of organic solvents were studied 

 and "solvent bands" were found for a number of the solvents used. Isomeric 

 solvents showed different bands for a given salt. The second problem was the 

 change in the spectrum which takes place as one salt of a metal is transformed into 

 another salt. The effect of oxidizing agents on uranous salts was especially investi- 

 gated. Mild oxidizing agents oxidized the "hydrated" salt and left unaffected 

 the "alcoholated" salt an example of selective oxidation. The effect of rise in 

 temperature on the absorption spectra of solutions was also studied. By means of a 

 closed cell, devised for the purpose, temperatures as high as 195 were used with 

 alcoholic solutions. The absorption bands widen with rise in temperature, colored 

 solutions in general becoming more opaque. It was also found that the ''water" 

 bands of any given salt are more affected by rise in temperature than the "alcohol" 

 bands ; showing that the hydrates are less stable with rise in temperature than the 

 alcoholates. These are but a few of the many relations brought out by the work. 



No. 170. JONES, HARRY C., and A. M. CLOVER, H. H. HOSFORD, S. F. HOWARD, C. A. 

 JACOBSON, H. R. KREIDER. E. J. SHAEFFER, L. D. SMITH, A. SPRINGER, 

 JR., A. P. WEST, G. F. WHITE, E. P. WIGHTMAN, and L. G. WINSTON. 

 The Electrical Conductivity, Dissociation, and Temperature Coefficients 

 of Conductivity, from Zero to Sixty-five Degrees, of Aqueous Solu- 

 tions of a Number of Sails and Organic Acids. Octavo, iv+148 pages, 

 5 text figures. Published 1912. Price $1.50. 



The work recorded in this monograph was undertaken especially because, when 

 reference is made to the literature for the conductivity of any electrolyte at any 



