October ig, lyiij 



NATURE 



33 



the method of assaying gold in order to test its fineness is 

 illustrated in a series of twelve operations by Messrs. 

 Johnson and Matthey, who have also supplied the platinum 

 electrodes for analysis. First a gold link taken from a 

 watch chain is shown, (.2) the hammered gold, (3) the rolled 

 gold, (.4) a weighed quantity ready for assay, (5) the gold 

 with a piece of silver wrapped in lead, (6) the same in a 

 cupel, (7) the gold-silver alloy . hammered and tolled after 

 cupelation, (9) the rolled and coiled alloy in the parting 

 flask, (10) the gold after parting with nitric acid, (11) the 

 gold annealed, (12) the assayist's report. The assay balance 

 and muffle employed in such operations are also shown. 

 In still another pari "I the same bench various crucibles 

 and other apparatus used in assay work are shown by the 

 Morgan Crucible Co. 



At another bench Messrs. Townson and Mercer show a 

 large assortment of apparatus employed in various opera- 

 tions. Thus there is a centrifuge operated by means of an 

 electromotor which is shown in operation. There is also 

 apparatus for the analysis of explosives, and general 

 apparatus, such as the Lewis Thompson calorimeter, hot- 

 air ovens, vacuum drying apparatus, &c. A portion of 

 this bench, which is provided with water and electrical 

 heating, is reserved for general demonstrations, such as 

 operations of filtration, crystallisation, precipitation, and 



Fig. z. — Bacteriobg ical Buich where demou&tra lions wti 



so on. Demonstrations in dyeing are also given here, and 

 the action of dyes on mordanted and unmordanted cotton, 

 silk, &c, illustrated. The apparatus for dyeing and 

 material for these experiments are supplied by Messrs. 

 Read Holliday, of Huddersfield. 



Following this bench is a draught cupboard, which con- 

 tains apparatus for the generation of sulphuretted 

 hydrogen, carbon dioxide, and so on. 



On the next bench the various apparatus employed in 

 the analysis and examination of mineral oils is exhibited ; 

 for example, the method of estimating the viscosity by 

 means of the viscometer is show-n in operation, and also 

 the taking of flash-points. Most of this apparatus is 

 exhibited by Messrs. Baird and Tatlock, but the Mahler- 

 Cook bomb calorimeter is shown by Messrs. J. J. Griffin 

 and Sons, Ltd. There is also on the shelves a fine dis- 

 play of reagents and pharmaceutical products exhibited 

 by Messrs. T. Morson and Son. On the opposite side of 

 the bench the various apparatus employed in gas analysis 

 is shown. There is also a good display of silica apparatus 

 by the Silica Syndicate and the Thermal Syndicate. This 

 apparatus has attracted a very great amount of attention, 



XO. 2I90, VOL. 87] 



as in Italy it was generally not known that silica apparatus 

 was manufactured in England. 



At the end of the laboratory a long bench is devoted to 

 bacteriology, where Messrs. Baird and Tatlock make a 

 display of the various apparatus used in bacteriological 

 work, and also show cultures on solmedia, a powdered 

 form of bacteriological culture. At another portion of the 

 demonstration bench Messrs. Edward Cook and Co., the 

 well-known soap-makers, have a demonstrator who shows 

 the methods employed in the standardisation of dis- 

 infectants by the Rideal-Walker method and by the Lancet 

 method. 



On the next bench there is a working laboratory 

 apparatus exhibited by Ozonair, Ltd., showing the forma- 

 tion of ozone. On another part of the bench there is a 

 most interesting exhibit of old chemical apparatus used in 

 the eighteenth century, kindly lent by the Society of 

 Apothecaries, London. 



In the centre of one side of the room Messrs. Burroughs, 

 Wellcome and Co. have an exhibit showing the results 

 obtained by the firm in research work, and in the manu- 

 facture of substances of pharmacological importance. 

 Thus the formation of ernutin from ergot is graphically 

 displayed. Investigations in the Wellcome Physiological 

 Research Laboratories have shown that ergot contains at 

 least three active principles, and the 

 exhibit is intended to show the produc- 

 tion of these. This exhibit is of great 

 interest, and demonstrates the high 

 value of chemical research in technical 

 operations. 



There is also a lead-covered distilla- 

 tion bench, on which are shown the 

 processes of distillation, fractionation, 

 and extraction in operation. 



This part of the British exhibit has 

 attracted great attention, and the Board 

 of Trade has been highly commended 

 by other nations upon the new de- 

 parture. At the same time, it must be 

 mentioned that the whole of the British 

 Section is most creditable to the 

 Exhibitions Branch of the Board of 

 Trade, without which it w^ould not 

 have been possible. Thus there is a 

 splendid exhibit of textiles, and the 

 exhibit of British motor-cars has 

 attracted a large amount of interest. 

 There is also a good exhibit of 

 agricultural machinery and imple- 

 ments. 



Most excellent catalogues have been 

 drawn up to explain the various 

 exhibits. The catalogue for the Mathe- 

 matical and Scientific Instrument 

 ;l " : " Section is in French and is splen- 



didly illustrated. The apparatus is 

 most carefully and fully described both from the theo- 

 retical and practical aspect, and Mr. E. H. Rayner, 

 who edited the catalogue, is to be congratulated upon its 

 excellence. 



The Catalogue of Chemical Industries, of which there is 

 an English and French edition, commences with articles 

 descriptive of the following industries, which have been 

 written or revised by the persons whose names accompany 

 the articles :— The alkali industry, J. F. L. Brunner and 

 J. I. Watts; sulphuric acid and nitric acid, Dr. F. Mollwo 

 Perkin ; the gas industry and coal-tar products. Prof. 

 Vivian Lewes, cyanides and prussiates, A. Gordon Salamon 

 and Dr. G. T." Beilbv ; electricity, Dr. G. T. Beilby ; 

 explosives. Walter F. Reid ; nickel, J. F. L. Brunner : 

 oils, fats and waxes, snaps and candles, Dr. J. Lewowitsch ; 

 petroleum and shale oil, Sir Boverton Redwood, Bart. ; 

 pharmacy, Thomas Tyrer and N. H. Martin ; salt, 

 J. F. L.' Brunner and J. I. Watts: disinfectants and anti- 

 septics, Dr. D. Somerville : rare metals, Dr. F. Mollwo 

 Perkin. The catalogue is thus a small treatise on technical 

 chemistrv. 'lhe second part of the catalogue deals with 

 the actual exhibits. 



