38 Chemistry and Physics 



important of these is the evidence furnished from the lowering of the freezing-point 

 of water with which a salt crystallizes and its power to lower the freezing-point of 

 water when dissolved in that solvent. This is shown to be a strong argument in 

 favor of the theory of hydration in aqueous solutions. The freezing-point of be- 

 tween 1,200 and 1,500 solutions of more than 100 compounds were measured, and 

 the results are here recorded. Experimental evidence was also obtained which 

 showed that salts dissolved in alcohol frequently combined with more or less of that 

 solvent, forming alcoholates. The theory of hydration in aqueous solutions thus 

 becomes the theory of solvation in solution in general. 



The second part of this monograph deals with the absorption spectra of solu- 

 tions from the standpoint of the hydrate theory. The absorption spectra were 

 obtained with a grating spectroscope, and solutions both in water and in the alcohols 

 were studied, also solutions in mixtures of the alcohols with water. The effects 

 of concentration of the solution and of the presence of a dehydrating agent were 

 tested ; also the effect of adding varying amounts of water to the solutions in the 

 alcohols. The results all fall in line with the hydrate theory, and can be interpreted 

 in terms of no other conception thus far advanced. 



No. 80. JONES, HARRY C, and C. F. LINDSAY, C. G. CARROLL, H. P. BASSETT, E. C. 

 BINGHAM, C. A. ROUILLER, L. McMASTER, and W. R. VEAZEY. Con- 

 ductivity and Viscosity in Mixed Solvents. Octavo, v-f-235 pages, 103 

 text figures. Published 1907. Price $2.00. 



This publication deals with conductivity and viscosity in mixed solvents. The 

 conductivities of a large number of salts in water, methyl and ethyl alcohols, and 

 acetone were studied, and the relation between these conductivities and the vis- 

 cosities of the several solvents, including especially the mixed solvents. A large 

 number of relations were brought out, showing that the viscosity of the solvent, 

 or solvent mixture, is a prime factor in conditioning the conductivity of dissolved 

 electrolytes. It was shown that the effect of one associated solvent on the association 

 of another associated solvent, with which it is mixed is to lessen its association. The 

 minima in the conductivity curves obtained in mixed solvents were also explained. 



The bearing of the temperature coefficients of conductivity on the hydrate 

 theory is discussed, and the meaning of negative temperature coefficients pointed out. 

 The lowering of the viscosity of water produced by certain salts is considered, and 

 the first satisfactory explanation of this important phenomenon given. 



No. 110. JONES, HARRY C., and JOHN A. ANDERSON. The Absorption Spectra of 

 Solutions. Octavo, vi-j-1 10 pages, 81 plates. Published 1909. Price $3.50. 



This monograph deals entirely with the absorption spectra of solutions of cer- 

 tain salts of cobalt, nickel, copper, iron, chromium, neodymium, praseodymium, 

 and erbium in water, methyl alcohol, ethyl alcohol, and acetone; and in mixtures 

 of water with the other solvents. The work recorded takes up the subject of the 

 absorption spectra of solutions in a fairly comprehensive manner. Among the 

 problems studied are the effect on the absorption of light produced by changing 

 the concentration of the solution but keeping the total amount of coloring matter 

 in the path of the beam of light constant; the effect of dehydrating agents; the 

 absorption spectra in methyl and ethyl alcohols, as well as in water and in acetone, 

 is also brought within the scope of this work. 



Some surprising results were obtained, especially with the salts of neodymium 

 in the alcohols. It was found that neodymium chloride showed one set of bands 

 in aqueous solutions, but some entirely new bands made their appearance in the 

 alcoholic solutions. In mixtures of water with the alcohols both sets of bands 

 came out simultaneously. The nature of absorption of light by solutions in general 

 is discussed at some length. Heliotype reproductions of 81 plates of spectrograms 

 are given, including about 1,200 solutions. All these data are explained with perfect 

 ease by means of the general theory of solvation in solution, but a large number 

 of the facts brought to light in this work are not explicable in terms of any other 

 suggestion thus far advanced. 



