ON THE ELECTROLYTIC METHODS OF QUANTITATIVE ANALYSIS. 295 



TJie Electrolytic Methods of Quantitative Analysis.— Fourth Report of the 

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

 man), Dr. C. A. KoHN (Secretary), Professor P. Franbxand, Pro- 

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

 and Professor W. Carleton Williams. 



Since the last report, which included an examination of the electrolytic 

 methods for the determination of bismuth, antimony, and tin, and for the 

 separation of the two latter, the experimental work of the Committee has 

 been continued. The investigations on the determination of cobalt, nickel, 

 and zinc are practically finished ; also further work on the determination 

 of bismuth and its separation from other metals ; but the Committee prefer 

 to delay the publication of these results until the next report in order to 

 make them as complete as possible. 



The Committee ask for reappointment, with a grant of 10/, 



The Frodiiction of Haloids from Pure Materials. — Report of the 

 Committee, consisting of Professor H. E. Armstrong, Professor 

 W. R. Dunstan, Mr. C. H. Bothamley, Mr. J. T. Cundall, and 

 Mr. W. A. Shenstone (Secretary), appointed to investigate the 

 Production of Haloids from Highly -purified Materials. 



The investigation undertaken by this Committee, as has been previously 

 reported, has been greatly delayed by the difficulty experienced in their 

 attempts to obtain a supply of chlorine satisfactory, both as regards origin 

 and quality, for the work to be done. 



During the past year, however, the Secretary has succeeded in pre- 

 paring (by the electrolysis of silver chloride) a suitable supply of the 

 element in question. 



A full account of the method of obtaining chlorine from this 

 source, and of the experiments that have been made with it, has already 

 been pubHshed in the ' Journal of the Chemical Society of London.' ' 

 It is therefore only necessary to state that novel and stringent means 

 were taken to secure the dryness of all the materials employed in the 

 various experiments, and that advantage has been taken of the oppor- 

 tunity which has arisen to examine once more the behaviour of chlorine 

 in sunlight, and also its behaviour under the influence of the silent 

 discharge of electricity. 



The following is a summary of the chief results obtained : — 



1. The introduction of a new source of highly-purified chlorine. 



2. The observation that highly-purified chlorine, after it had been 

 dried by new and very stringent methods, still interacted rapidly and 

 completely with specimens of highly-purified and carefully dried mercury 

 made by several diSerent methods. 



3. That highly-purified and carefully dried bromine reacts readily 

 and completely with purified mercury. 



' 'Observations on the Properties of some Highly -purified Substances,' Trans. 

 Chem. Sic, 1897, by W. A. Shenstone. 



