6 Conductivity of Aqueous Solutions. Part I. 



acetic acid, and ammonium acetate, and has derived from them the ioniza- 

 tion of water at that temperature. The results are also presented in 

 Part VII. 



Mr. G. W. Eastman has investigated a number of other acids, namely, 

 nitric, phosphoric, and sulphuric acids, and potassium hydrogen sulphate, 

 and the base, barium hydroxide, at 25 or 28 intervals from 18 to 156, 

 and has extended some of these measurements and the previous ones with 

 hydrochloric acid to 260 and 306. The data and conclusions in regard 

 to these substances are presented in Part VIII. 



In order to obtain at temperatures of to 25 values for the ionization 

 of water more accurate than those previously existing, Dr. C. W. Kanolt 

 has studied by the same conductivity method as was used with ammonium 

 acetate at higher temperatures the hydrolysis of an ammonium salt of a 

 much weaker acid, diketotetrahydrothiazole. The results of this work 

 are presented in Part IX. 



Only a beginning has been made in the study of the solubility of salts 

 at high temperatures. Dr. Wilhelm Bottger has, however, already deter- 

 mined that of three difficultly soluble silver salts at 100, and the results 

 are recorded in Part X. 



It has also seemed advisable to include in this publication an account of 

 a research carried out by Mr. Yogoro Kato and myself with the view of 

 determining the equivalent conductance of the hydrogen ion ; for though 

 this consisted in transference experiments at 20 with nitric acid of 

 various concentrations, and was thus distinct as far as the method is 

 concerned from the other researches to be here described, yet the knowl- 

 edge furnished by it has a direct bearing on the interpretation of conduc- 

 tivity results. The investigation is described in Part XL It is entirely 

 analogous to one previously made with hydrochloric acid by Noyes and 

 Sammet* for the same purpose. 



Finally a general summary and discussion of the more important results 

 of the whole series of investigations are presented in Part XII. 



The reader who is interested only in the more general conclusions 

 drawn from the work is recommended to turn at once to this summary in 

 Part XII. Anyone who desires fuller information in regard to the con- 

 ductivity and ionization of the specific substances and to the method of 

 discussion of the results will find this information as a rule in the last 

 five or six sections of the separate parts. The earlier sections in each 

 part are devoted to a detailed description of the experiments and presen- 

 tation of the original data, and will be of interest principally to investi- 

 gators who desire to make similar experiments and to those who wish to 

 criticize the results or form an estimate of their accuracy. 



*The Equivalent Conductivity of the Hydrogen Ion derived from Transference 

 Experiments with Hydrochloric Acid. J. Am. Chem. Soc, 24, 944-968 (1902), or 

 Z. phys. Chem., 43, 49-74 (1903). 



