ON THE ELECTROLYTIC METHODS OF QUANTITATIVE ANALYSIS. 171 



The Electrolytic Methods of Quantitative Analysis — Sixth Report of the 

 Committee, consisting of Professor J. Emerson Reynolds {Chair- 

 man), Dr. 0. A. KoHN (Secretary), Professor P. Frankland, Pro- 

 fessor F. Clowes, Dr. Hugh Marshall, Mr. A. E. Fletcher, 

 and Professor W. Carleton Williams. 



The work of the Committee, appointed in 1894, has hitherto included a 

 complete bibliography on electrolytic analysis up to the end of 1894 and 

 experimental investigations on the electrolytic determination of antimony, 

 bismuth, cobalt, nickel, zinc, and the separation of antimony and tin. 



The present report deals with further work on the determination of 

 bismuth, and with the determination of iron, its separation from man- 

 ganese, and the application of the electrolytic method to the determination 

 of iron in organic products. 



These experiments cover some of the most important applications of 

 electrolytic analysis which required further investigation, and the 

 Committee propose to conclude their work with the present report. 



The more recent bibliography of the subject has been summarised by 

 Neumann.^ The Committee would also refer to Neumann's book on 

 electrolytic analysis,'^ which has been issued since their bibliographical 

 report, and an English translation of which has been prepared by 

 Kershaw ; ^ also to the annual reports on electrolytic analysis published 

 in the ' Jahrbuch fiir Elect rochemie.' 



The Determination of Bismuth {Part II.) By Professor J. Emerson 

 Reynolds, D.Hc, M.D., F.B.S., and W. C. Ramsden. 



In a previous report (1896) it was shown : — 



1. That carefully spun platinum dishes were better suited for use 

 as negative electrodes than any other of the various forms experimented 

 with. 



2. That iri-egular results only could be obtained with simple bismuth- 

 nitrate solutions containing varying proportions of free nitric acid ; but 

 that good determinations were more easily made in solutions of the 

 sulphate when electrolysed by currents beginning at 0-08 and finishing 

 at not more than 0'2 ampere. 



.3. That the best results were obtained in presence of metaphosphoi-ic 

 acid and of citric acid, both of which controlled deposition in a very 

 marked manner. 



4. That citric acid is quite as effective as metaphosplioric acid and 

 possesses the additional advantage that the metal can also be separated in 

 satisfactory condition from ammoniacal solutions of the citrate. 



Two questions i-emained for consideration, viz. {a) the separation of 

 bismuth from strong but simple solutions, and (b) from solutions con- 

 taining other metals. 



'o 



' Chem. Zeits. 1900, 24, 455. 



• Thcorio II. Prams der annhjtlsclieii Mectroljisc der Mctallc, 1897. 



' The Theory and Practice of Ekctrolytic Methods of Analysis, 1898. 



