610 



SCIENCE. 



[N. S. Vol. IV. No. 95. 



CHEMISTRY AT TEE BRITISH ASSOCIATION. 



The address of Dr. Ludwig Mond, Presi- 

 dent of the Chemical Section at the Liver- 

 pool meeting of the British Association, was 

 on the History of the Manufacture of 

 Chlorin. After sketching the earlier meth- 

 ods, Dr. Mond treated very fully the Weldon 

 and the Deacon processes, and then gave 

 the details of his own work on the recovery 

 of the chlorin in the Solvay process of soda- 

 manufacture. In outline, Mond's process 

 is as follows : The ammonium chlorid, ob- 

 tained in a very pure condition by crystal- 

 lization from the refrigerated liquors of the 

 Solvay process, is passed as a vapor over 

 hot pills of a mixture of magnesia, potassium 

 chlorid and china clay. Ammonia is given 

 off and condensed, while the chlorin unites 

 with the magnesia. The pills are then 

 heated more strongly and hot air passed 

 over them ; the magnesia is regenerated 

 and the chlorin given off, to be absorbed by 

 lime for bleaching powder. By this method, 

 which has been in commercial operation for 

 several years at Winnington, the Solvay 

 process is able to compete with the LeBlanc 

 process in the manufacture not only of soda, 

 but of bleaching powder. In conclusion 

 Dr. Mond referred to promising develop- 

 raents along the line of the manufacture of 

 chlorin by electrolysis. 



The paper which attracted the most at- 

 tention in the Chemical Section was that of 

 Prof. Bamsay on Helium. It was mainly 

 devoted to his diffusion experiments, al- 

 ready described in this Jouenal. He said 

 he was about to carry out experiments on 

 oxygen and nitrogen, in order to determine 

 if they can be resolved by the diffusion pro- 

 cess into constituents of slightly different 

 density. In the course of the discussion 

 which followed the paper, Dr. Mond spoke 

 of argon and helium as being a kind of 

 matter different from the ordinary chemical 

 elements, and having no chemical afl&nities 

 and characteristics. He did not consider it 



improbable that there might be a whole 

 series of substances not belonging to chem- 

 istry, whose existence seemed not only to 

 upset the fundamental law of chemistry, 

 Dalton's Law, but also to cast doubt on the 

 present fundamental notions regarding 

 physical science. 



It may be noted that the idea that all the 

 atoms of an element may not have the 

 same weight is not a new one first broached 

 in the case of helium, but it was some years 

 ago suggested by Prof. Crookes in connec- 

 tion with his work on rare earths. 



Prof. Dewar read a paper on Low Tem- 

 perature Besearch, urging especially the 

 necessity of physical investigation. He de- 

 scribed a very accurate method of making 

 specific gravity determinations in liquid 

 oxygen. 



Dr. F, Hurter discussed the manufacture 

 of chlorin by means of nitric acid, and said 

 that in spite of its theoretical advantages 

 it had not proved a commercial success, nor 

 did it give promise for the future. 



Prof. Liebreich, of Berlin, repeated a series 

 of experiments before the Section with a 

 view to proving the diminution of chemical 

 action resulting from the limitations of 

 space. He advanced the general proposi- 

 tions that liquids, in proportion as they are 

 placed in confined spaces, acquire by equi- 

 libric reactions the properties of solids; 

 and that friction in such fluids has a bear- 

 ing of considerable importance on chemical 

 reaction. 



Dr. William Newton, of London, described 

 very fully the nitrate deposits of Chili, and 

 deprecated very strongly the present crude 

 and wasteful methods of mining and 

 working up the products. 



One of the most interesting papers was 

 by Sir Henry Boscoe on Chemical Educa- 

 tion in England and Germany. England is 

 feeling very keenly the fact that Germany 

 is along most lines monopolizing the chemi- 

 cal industry of the world. While larger 



