IV. Quantitative Methods for the Separation of Metals by means of Electrolysis—continued. Journal Freudenberg, H.. Zeits. phys. Chem. 1893 Luckow, C.. Richè, A. Smith, E. F., & Frankel, L. K. J. Analyt. & App. Chem. J. Analyt. & App. Chem. 121 13. SILVER. As, Cd, Co, Cu, Ni, Pt, Zn As, Cd 97 Sb Bi 345 Pb 508 SPb Zn 254 Cu 104 Cu, Ni, Zn Potassium cyanide. 428 As, Mo, W Potassium cyanide. 417 Pt Potassium cyanide. Indirect determination of potassium, ammonium, and nitrogen. Oxidation of metallic arsenides by the electric current. Indirect determination of chlorine and bromine electrolytically. Determination of carbon in steel. The electrolytic estimation of copper as applied to invert-sugar determinations. Oxidation of chalcocite by the electric current. Indirect determination of chlorine, bromine, and Author Journal Year Volume Page 1019 2276 313 2182 414 Vortmann, G. Ber. 1890 23 2798 VI. Applications of Electrolysis to Qualitative Analysis (including sundry Papers bearing on Electrolytic Analysis). Subject Detection of lead and manganese in presence of iron Detection of poisonous metals in mixtures contain- Detection of antimony in organic matter and in Detection of metallic poisons (copper, zinc). Electrolysis of metallic thiocyanates. Detection of manganese in zinc and zinc ores. Detection of metallic poisons and of antimony, Electrolysis of salts of the rare earths. Detection of mercury. Detection of lead and manganese. Electrolysis of salts of chromium, alkali sulphides, Detection of gold. Detection of silver. Conditions under which oxides formed during elec- Electrolysis of salts of cerium, didymium, tungsten, Detection of mercury. 1880 13 751 1883 114 Pharm. Central Halle 1886 608 Detection of arsenic. Zeits, angew. Chem. 1888 294 1891 22 493 Detection of arsenic. Detection of mercury. 3712 The Bibliography of Spectroscopy.--Report of the Committee, consisting of Professor H. MCLEOD, Professor W. C. ROBERTS AUSTEN, Mr. H. G. MADAN, and Mr. D. H. NAGEL. PROGRESS has been made with the catalogue of spectroscopic literature, which has now been brought nearly up to date; but, in view of the difficulty of obtaining assistance from any one who is within reach of the great scientific libraries, the Committee do not see their way to its further continuance. They therefore propose to bring the catalogue to a conclusion at the end of the present year, so as to form a twenty-five-years' record of spectroscopic literature. Four instalments of the list of papers have been already issued, and will be found in the reports of the Association for 1881, 1884, 1889, and 1894. The inconvenience of having to refer to four distinct volumes in order to obtain a complete list of papers on any particular subject is obvious, and the Committee strongly recommend that all the separate instalments should be collected, rearranged, and issued as one continuous catalogue. Mr. Madan is quite willing to undertake gratuitously all the labour of doing this, the only question is that of expense of printing. In an estimate obtained last year, Messrs. Spottiswoode & Co. stated that the cost of printing 500 copies of the first three instalments (1881, 1884, and 1889) would be about 951. The cost, therefore, of printing the whole catalogue would be about 1307. If the above recommendation is approved by the Association, the Committee would suggest that the Association might undertake the responsibility of the cost of printing, and be recouped (in part at least) by the charge of 2s. 6d. per copy (which would produce 627. 10s.). Or a higher charge might be made. It appears, moreover, not unlikely that other scientific societies—the Royal Society, the Chemical Society, and the Physical Society-might be induced to make grants, if, as is hoped, the catalogue would be of value to those who are engaged in physical research. The Committee desire to present the above subject for discussion, and ask to be reappointed for one more year in order to finish their work. The Action of Light upon Dyed Colours.-Report of the Committee, consisting of Dr. T. E. THORPE (Chairman), Professor J. J. HUMMEL (Secretary), Dr. W. H. PERKIN, Professor W. J. RUSSELL, Captain W. DE W. ABNEY, Professor W. STROUD, and Professor R. MELDOLA. (Drawn up by the Secretary.) DURING the past year (1894-95) the work of this Committee has been continued, and a large number of wool and silk patterns, dyed with various natural and artificial red, orange, and yellow colouring matters, have been examined with respect to their power of resisting the fading action of light. Similar patterns were exposed to light in the years 1892-93 and 1893-94, and have already been reported upon, but for want of sufficient exposing space certain important groups of colouring matters had to remain unrepresented, e.g., the Congo Reds, &c. These have now been examined, together with additional coal-tar colouring matters recently introduced, also certain Indian dyestuffs. With some few exceptions, therefore, all the available red, orange, and yellow colours, as applied to wool and silk, have now been exposed. The general method of preparing the dyed patterns, and the manner of exposing them under glass, with free access of air and moisture, were the same as already adopted. The thanks of the Committee are again due to James A. Hirst, Esq., in whose grounds the patterns were exposed at Adel, near Leeds. Each dyed pattern was divided into six pieces, one of which was protected from the action of light, while the others were exposed for different periods of time. These 'periods of exposure' were made equivalent to those adopted in previous years by exposing, along with the patterns, special series of 'standards,' dyed with the same colouring matters as were then selected for this purpose. The standards were allowed to fade to the same extent as those which marked off the 'fading period ' in previous years, before being renewed or removing a set of dyed patterns from the action of light. The patterns exposed during the past year are therefore comparable, in respect of the amount of fading which they have experienced, with the dyes already reported upon. The patterns were all put out for exposure on June 20, 1894, certain sets being subsequently removed on the following dates :-July 14, August 20, September 22, 1894; April 13, July 16, 1895. Of these five 'periods of exposure' thus marked off, periods 1, 2, 3 were equivalent to each other in fading power, whereas periods 4 and 5 were each equivalent to four of the first period in this respect; hence five patterns of each colour have been submitted respectively to an amount of fading equal to 1, 2, 3, 7, and 11 times that of the first 'fading period' selected-viz. June 20 to July 14, 1894. The dyed and faded patterns have again been entered in pattern-card books in such a manner that they can he readily compared with each other. The following tables give the general result of the exposure experiments made during the year 1894-95, the colours being divided, according to their behaviour towards light, into the following five classes: very fugitive, fugitive, moderately fast, fast, very fast. The initial numbers refer to the order of the patterns in the patternbooks. The S. and J. numbers refer to Schultz and Julius's Tabellarische Uebersicht der künstlichen organischen Farbstoffen.' In the case of colouring matters requiring mordants, the particular mordant employed is indicated in brackets after the name of the dyestuff. RED COLOURING MATTERS. CLASS I. VERY FUGITIVE COLOURS. (WOOL.) The colours of this class have faded so rapidly that at the end of the first 'fading period' (June 20 to July 14, 1894) only a very faint colour remains, and at the end of the fifth period (one year) all traces of the original colour have disappeared, the woollen cloth being either quite white or merely of a faint tint which varies according to the colour of the original pattern. |