if the variation of an additive property with composition is to be expressed by a straight line were briefly summarised. "A Method of Rock-Analysis Diagrams Based on Statistics." By W. A. RICHARDSON. Oxide variation diagrams, similar to those employed by Dr. Harker, can be used for expressing the chemical relations of rock groups and individuals. The diagrams obtained from plotting Iddings' selected analyses gave the maximum variation for all rocks. "Identity of Trechmann's ' -tin' with Stannous Sulphide." By L. J. SPENCER. A re-examination of the original material described by C. O. Trechmann in 1879 as an orthorhombic modification of tin proved that he made his crystallographic determinations on crystals of one kind (viz., stannous sulphide), whilst the chemical analysis was made on crystals of another kind (viz., metallic tin). Tin is therefore dimorphous and not trimorphous, "white tin" being tetragonal, and "grey tin" cubic. Orthorhombic crystals of stannous sulphide (SnS) and tetragonal crystals of iron stannide (FeSn,) from tin fur. naces, and rhombohedral crystals of tin arsenide (Sn,As) isolated from a tin-arsenic alloy were described. THE SOCIETY OF GLASS TECHNOLOGY. Wednesday, January 19, 1921. DR. M. W. TRAVERS, F.R.S., in the Chair. The Fortieth Meeting of the Society of Glass Technology was held in the Mappin Hall, Applied | Science Department, The University, Sheffield. The first paper presented was entitled :— "The Rate of Change of Glass Composition in a Tank Furnace following a Change in the Batch Composition." By JOHN CURRIE, M.A. tons. In this paper, which was given by Prof. W. E. S. Turner, the author stated that the tank furnace in question had a dead-weight capacity of 106 During six working days in the week, filling on took place every two hours, the quantity added being made up of 30cwt. of batch and 4cwt. of cullet, derived directly from the working end. Originally, the metal in this tank was used for bottles made on Forster machines. In place of these there were installed semi-automatic O'Neill machines, with Hartford-Fairmont feeder. It was thus necessary to produce a glass of lower melting point and slower rate of setting. The batch was altered accordingly, so as to reduce the percentage of lime, at the same time increasing the percentage of alkali in the glass.. At various dates after the new batch was put into use, a sample bottle was taken for analysis, and the density of the glass was also determined. The main fact established in the paper was that a period of nearly three months was required to effect a radical change in the composition of the tank. After that period, the composition of the glass was nearly identical with that calculated from the new batch, the percentage of lime being 7:42 as compared with 678 in the theoretical composition. The discussion that folowed this paper was exceptionally interesting, those taking part being the Chairman, Messrs. R. L. Frink, W. J. Rees, G. Simpson, J. H. Davidson, A. E; Hill, J. Connolly, and Th. Teisen. In the absence of the author, Prof. Turner replied. Two other papers were presented, namely: (a) "Problems arising in Tank Furnace Practice through Shortage of Saltcake." By PROF. W. E. S. TURNER. (b) "The Relative Advantages and Disadvan tages of Limestone, Burnt Lime, and Slaked Lime as Batch Materials." By F. W. HODKIN, B.Sc, and PROF. W. E. S. TURNER. These two papers were taken together, and presented by Prof. Turner. The relative advantages of saltcake and soda ash were discussed. It was pointed out that soda ash was generally - much purer than saltcake, that it gave glass a considerably greater proportion of its weight than did saltcake, and that soda ash batch would melt more> rapidly and readily than a saltcake batch. It was also alleged that saltcake had a more corrosive action than soda ash on the refractory materials* of the furnace. Further, soda ash was usually transported on the railways more carefully than saltcake. The price had also to be considered, and an answer given to the question as to what happened when saltcake could not be got. Various substitutes had been tried with success. In some cases one-half or two-thirds of the saltcake had been replaced by a corresponding amount of soda ash. Attention was directed to an observation made by Mr. Golstharp, chemist to the Pittsburgh Plate Glass Co., U.S.A., to the effect that a good clear glass, having more than a certain lime content, could not be made with a wholly soda ash batch. In A number of lantern slides were presented showing the results of experiments made with small melts in which there were tried soda ash and salt cake batches, and also a mixture of these. these experiments, they had tried in turn as the source of the alkali in the glass (1) limestone, (2) burnt lime, and (3) slaked lime. What resulted depended in a considerable degree upon the nature or form in which the lime was placed in the batch. In addition, there were other factors. Burnt lime may be expensive, but the burning of lime did not get rid of organic matter which had a reducing action in the tank, and therefore tended to make the colour poor. On the other hand, there were difficulties in handling burnt lime, while it also readily absorbed moisture and carbon dioxide. Limestone tended to make a batch more expensive, but when melted it gave off a considerable quantity of gas, which helped mechanically to stir up the glass, thereby giving greater homogeneity. A discussion followed, in which there took part the Chairman, Messrs. W. J. Rees, R. L. Frink, G. Simpson, and J. Connolly. Mr. Hodkin and Prof. Turner replied. CHEMICAL NOTICES FROM FOREIGN SOURCES. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences. Vol. clxxi., No. 23, December 6, 1920. SPECTRUM ANALYSIS. Table of the most persistent lines of the elements, which should help in analysis.-M. A. DE GRAMMONT.-This work is the outcome of work carried out by the author during the last few years for many industries and Government Departments. The raies ultimes are designated by the symbols 1. 2. 3. showing their order of persistence, being the last to disappear, The dominant lines are printed in heavy type, and those which are next in order are printed in ordinary type. The wave-lengths in the table are expressed in international Angström units. A certain number of the visible lines, principally those lower than 4800, have been placed in the column crown uviol glav spectrograph because they have been determined with this apparatus. Chemical Notices from Foreign Sources.-THE DOMINANT LINES IN THE SPECTRUMS OF THE ELEMENTS. Quartz Spectrograph. 24378; 2416′2′′; 2316·1„ ; 2303*0,. 4, By Photography. "Uviol Crown" Glav Spectrograph. ... Phosphorus Platinum 39664, 3923'0; 3268.4 ... 4047-21; 4044-2; 34474 ; 3064'7: 2529.8; 2734'0: 3499 0 ... (2) 63709; 63468; 50570; 5042°3 5465*5: 5209°1 ... 3383 02; 3280-71 ... 3303 0.2; 3302-42 4607.3μ; 4305'5; 4215·5μ2 ; 4077 8μ1 February 4, 1921 Pioneer Movement for Establishing a British Bureau of Standards., BRITISH CHEMICAL STANDARDS STEELS (Plain Carbon and Alloy) AND CAST IRON. Analytically standardised by, and issued under the auspices of Co-operating Chemists representing different districts and sections of industry. GOVERNMETEMISTS... DEPARTMENT ANALYSTS Users, Issuing WORKS CHEMISTS.. RAILWAY CHE Makers, Working to Specificatio n MOTOR OR AERO MAKERS CH+ MISTS... REFEREE ANALYSTS... Independent. Specifications. With every portion of standard turnings a Certificate is issued, showing the type of method used by each analyst, his results, and the average of at THE CHEMICAL NEWS. VOL. CXXII., No. 3174. EDITORIAL. WE have recently drawn attention to the impor tance of glassware in the chemical industry, and to the efforts that are being made by British glass manufacturers to render the country independent of foreign supplies. The Association of British Chemical Manufacturers have recently issued a statement pointing out the gravity of the situation as regards the production of fine chemicals which we are glad to publish, as these matters are of supreme national importance if we are to hold our own in the near future. Recent developments in Germany, both in home politics and in trade propaganda enhance the importance of increasing vigilance at the present moment A KEY INDUSTRY. Are Britain's Laboratories in peril? The Asso ciation of British Chemical Manufacturers draws attention to the present position of the Fine Chemical Industry. The position amongst us to-day may be simply stated. During the war we assembled from our polytechnics, colleges, and universities, men who, after much striving and many failures, did arduously acquire not only a knowledge of the explosives which destroy life, but of certain drugs, such as phenacetin, salicylates, and salversan that save it. But the plant which was then rigged up was emergency plant;, the methods were emergency methods in the circumstances, naturally expensive. Are we for these reasons to permit our little army of chemist experts to be scattered? Are we to hand back to Germany an industry so lucrative in time of peace and potentially so formidable for war? The Making of Medicines.-Or should we give ourselves a chance? It must not be imagined that our men have failed to make good. They have made good; or rather they are just on the point of doing so. The manufacture of research chemicals, of photographic chemicals, of synthetic perfumes and essences is each on the verge of commercial success. The manufacture of drugs has made immense strides; many; begun some time ago, have been brought to perfection; others had been added or were being added when the decision of Mr. Justice Sankey was dropped like a bomb into the thick of these experimentings. British manufacturers had proved that they could make fine chemicals as good as the fine chemicals of Germany, and they were slowly but quite surely bringing down the cost of making them, when suddenly the Order in Council prohibiting the im The next month or so will decide whether, in the years to come, Great Britain is to make fine chemicals for all the world, or whether we and the other nations are once more to turn to Germany for our laboratory and photographic chemicals, for essential drugs like antipyrin, phenace-portation of drugs was swept aside. tin, cocaine, salicylates, aspirin, salversan, and others. The case against buying these fine chemicals from the Germans is not founded on any foolish post-war prejudice against trading with a former enemy. It is a matter of international principle only less grave than the surrender of the High Seas Fleet and the reduction of the German Army. To-day it should not be necessary to remind any British citizen that it was Germany's phalanx of expert chemists with their experienced workmen who gave her so tremendous an advantage in the early days of the struggle. That military asset was, of course, the direct consequence of the fact that Germany had been chemical maker to the world; nor for several reasons was it possible in those days to compete with the laboratories which in a night were to become munition factories. For one thing, Germany had built up what was practically a monopoly in the fine chemical industry because the raw materials for that industry are largely the bye-products of the dye-stuffs industry -by that time, of course, almost a German monopoly. Mobilising the Chemists.-The war found her supreme, both in the necessary plant and in the knowledge, not readily acquired, of the most economical mode of production. But it did not leave her supreme; and it will be strange if we have since forgotten what we then learnt, namely, the unwisdom of leaving in the hands of any one nation the supply of drugs essential to our health, especially when that surrender places ready to her hand the plant needed for the manufacture of explosives and the chemists and the workmen skilled in its use. What has been the effect? Germany, it must be remembered, had long ago arrived at the point to which this new industry of ours was gradually struggling. She not only had her troops of industrial chemists; her plant was established and still intact; she had already made all the short cuts to cheap production. And in addition to these circumstances, the fact that the mark is now worth a penny instead of a shilling permits her to sell profitably on the British market at a price below our cost of actual manufacture. means an Wanted: A Breathing Space.-Inevitably that end to the fine chemical industry amongst us; unless British firms be given a breath. ing space to prepare for competition on fair terms. Many such firms are at this moment clinging to the hope that the Key Industries Bill which has been promised as the first Government measure of the next session will even yet permit our country to become eventually the source of the world's fine chemical supply. Just as the making of fine chemicals is the complement to the making of dyestuffs, so is this Bill a pendant of the Dyestuffs Act, already approved by overwhelming majority in the House of Commons. an There does not appear to be any weighty reason why we should send to other countries our coal tar, and other bye-products from the manufacture of dyes, to be made into chemicals by foreign labour in foreign plant erected by foreign capital. The only class amongst us who would benefit would be the handful of brokers who would get their commission out of selling over again such of the bye-products as came back to us in their manufactured state. |