additions the art has received in the last half century, and to offer a few statements to show the magnitude on which operations are conducted. As regards iron, in the last twenty-five years the price of steel has been reduced from 551. per ton to 51. per ton, but, after giving the world the inestimable boon of cheap steel by the labours of Bessemer and of Siemens, we were somewhat slow to accept the teaching of experiment as to the best method of treating the new material; on the other hand, Hadfield has brought manganese steel and aluminium steel within the reach of the manufacturer, and J. Riley has done much to develop the use of nickel steel.

In the case of copper, we have mainly contributed to extraordinary development of wet processes for its extraction from poor sulphides, and have met the great demands for pure metal by the wide adoption of electrolytic processes.

As regards the precious metals, this country is well to the front, for Great Britain and her colonies produce about 38 per cent. of the gold supply of the world; and it may be well to add, as an indication of the scale on which operations are conducted, that in London alone one ton of gold and five tons of silver bullion can easily be refined in a day. No pains have been spared in perfecting the method of assay by which the value of gold and silver is ascertained, and during my twenty years' connection with the Royal Mint I have been responsible for the accuracy of the standard fineness of no less than five hundred and fifty-five tons of gold coin, of an aggregate value of seventy millions five hundred thousand pounds sterling. In the case of the platinum industry we owe its extraordinary development to the skill and enterprise of successive members of the firm of Johnson, Matthey, & Co., who in later years have based their operations upon the results of the investigations of Deville and Debray. Some indication of the value of the material dealt with may be gathered from the statement that two and a half hundredweight of platinum may easily be melted in a single charge, and that the firm, in one operation, extracted a mass of palladium valued at 30,000l. from gold-platinum ore actually worth more than a million sterling.

I wish it were possible to record the services of those who have advanced metallurgy in connection with this Association, but the limitations of time render it difficult to do more than refer to some honoured names of past presidents of this Section. Michael Faraday, president of this Section in 1837 and 1846, prepared the first specimen of nickel-steel, an alloy which seems to have so promising a future, but we may hardly claim him as a metallurgist; nor should I be justified in referring, in connection with metallurgical research, to my own master, Graham, president of this Section in 1839, and again in 1844, were it not that his experiments on the occlusion of gases by metals have proved to be of such extraordinary practical importance in connection with the metallurgy of iron. Sir Lyon Playfair presided over this Section in 1855, and again in 1859. His work in connection with Bunsen on the composition of blast-furnace gases was published in the Report of this Association in 1847, and formed the earliest of a group of researches, amongst which those of Sir Lowthian Bell proved to be of so much importance. The latter was President of this Section in 1889. Sir F. Abel, President of this Section in 1877, rendered enduring service to the Government by his elaborate metallurgical investigations, in connection with materials used for guns and projectiles, as well as for defensive purposes. I will conclude this section of the address by a tribute to the memory of Percy. He may be said to have created the English literature of metallurgy, to have enriched it with the records of his own observations, and to have revived the love of our countrymen for metallurgical investigation. His valuable collection of specimens, made while Professor at the Royal School of Mines, is now appropriately lodged at South Kensington, and will form a lasting memorial of his labours as a teacher. He exerted very noteworthy influence in guiding the public to a just appreciation of the labours of scientific men, and he lived to see an entire change in the tone of the public press in this respect. In the year of Percy's presidency over this Section the Times' gave only one-tenth of a column to a summary of the results of the last day but one of the Meeting, although the usual discourse delivered on the previous evening had been devoted to a question of great importance-The application of Iron to Railway purposes.' Space was, however, found for the interesting state

ment that the number of Quakeresses who attended the meetings of the Sections was not a little remarkable.' Compare the slender record of the Times' of 1849 with its careful chronicle of the proceedings at any recent meeting of the Association.

In drawing this address to a close, I would point to the great importance of extending the use of the less known metals. Attention is at present concentrated on the production of aluminium, and reference has already been made to the Cowles process, in which, as in that of Héroult, the reduction of alumina is effected by carbon, at the very high temperature of the electric arc; while, on the other hand, in the Kleiner and similar processes, the electric current acts less as a source of heat than by decomposing a fluid bath, the aluminium being isolated by electrolytic action; and doubtless, in the immediate future, there will be a rapid increase in the number of metallurgical processes that depend on reactions which are set up by submitting chemical systems to electric stress. Incidental reference should be made to the growing importance of sodium, not only in cheapening the production of aluminium, but as a powerful weapon of research. In 1849, when Percy was president of this Section, magnesium was a curiosity; now its production constitutes a considerable industry. We may confidently expect to see barium and calcium produced on a large scale as soon as their utility has been demonstrated by research. Minerals containing molybdenum are not rare; and the metal could probably be produced as cheaply as tin if a use were to be found for it. The quantities of vanadium and thallium which are available are also far from inconsiderable; but we, as yet, know little of the action of any of these metals when alloyed with others which are in daily use. The field for investigation is vast indeed, for it must be remembered that valuable qualities may be conferred on a mass of metal by a very small quantity of another element. The useful qualities imparted to platinum by iridium are well known. A small quantity of tellurium obliterates the crystalline structure of bismuth; but we have lost an ancient art, which enabled brittle antimony to be cast into useful vessels. Twotenths per cent. of zirconium increases the strength of gold enormously, while the same amount of bismuth reduces the tenacity to a very low point. Chromium, cobalt, tungsten, titanium, cadmium, zirconium, and lithium are already well known in the arts, and the valuable properties which metallic chromium and tungsten confer upon steel are beginning to be generally recognised, as the last Exhibition at Paris abundantly showed; but as isolated metals we know but little of them. Is the development of the rarer metals to be left to other countries? Means for the prosecution of research are forthcoming, and a rich reward awaits the labours of chemists who could bring themselves to divert their attention, for even a brief period, from the investigation of organic compounds, in order to raise alloys from the obscurity in which they are at present left.

It must not be forgotten that metallurgical enterprise rests on (1) scientific knowledge, (2) capital, and (3) labour, and that if the results of industrial operations are to prove remunerative, much must depend on the relation of these three elements, though it is difficult to determine accurately their relative importance. A modern ironworks may have an army of ten thousand workmen, and commercial success or failure will depend in no small measure on the method adopted in organising the labour. The relations between capital and labour are of so much interest at the present time that I do not hesitate to offer a few words on the subject.

Many examples might be borrowed from metallurgical enterprises in this and other countries to show that their nature is often precarious, and that failure is easily induced by what appear to be comparatively slight causes. Capitalists might consequently tend to select Government securities for investment in preference to metallurgical works, and the labouring population would then severely suffer. It is only reasonable, therefore, that if capitalists are exposed to great risks, they should, in the event of success, receive the greater part of the profits. There is a widespread feeling that the interests of capital and labour must be antagonistic, and as it is impossible to ignore the fact that the conflict between them is giving rise to grave

apprehension, it becomes the duty of all who possess influence to strive not merely for peace, but to range themselves on the side of justice and humanity. The great labour question cannot be solved except by assuming as a principle that private ownership must be held inviolable, but it must be admitted that there was a time when capital had become arbitrary and some kind of united action on the part of workmen was needed in self-defence. If, however, we turn to the action of the leaders of trades unions in the recent lamentable strikes, we are presented with a picture which many of us can only view as that of tyranny of the most close and oppressive kind, in which individual freedom cannot even be recognised. There are hundreds of owners of works who long to devote themselves to the true welfare of those they employ, but who can do little against the influence of the professional agitator, and are merely saddened by contact with prejudice and ignorance. I believe the view to be correct that some system by which the workman participates in the profits of enterprise will afford the most hope of putting an end to labour disputes, and we are told that profit-sharing tends to destroy the workman's sense of social exclusion from the capitalistic board, and contents him by elevating him from the precarious position of a hired labourer. No pains should therefore be spared in perfecting a system of profit-sharing.

Pensions for long service are great aids to patience and fidelity, and very much may be hoped from the fact that strenuous efforts are being made by men really competent to lead. The report of the Labour Commission which is now sitting will be looked for with keen interest. Watchful care over the health, interests, and instruction of the employed is exercised by many owners of works; and in this respect the Dowlais Works, which are being transplanted into your midst at Cardiff, have long presented a noteworthy example. Workmen must not forget that the choice of their own leaders is in their own hands, and on this the future mainly depends. We may lay it down as a perpetual law that workmen's associations should be so organised and governed as to furnish the best and most suitable means for attaining what is aimed at, that is to say, for helping each individual member to better his condition to the utmost in body, mind, and property.' The words will be found in the Encyclical letter which Pope Leo XIII. has recently issued on the 'Condition of Labour.' To me it is specially interesting that the Bishop of Rome in his forcible appeal again and again cites the opinion of St. Thomas Aquinas, who was a learned chemist as well as a theologian.

Those of us who realise that 'the higher mysteries of being, if penetrable at all by human intellect, require other weapons than those of calculation and experiment,' should be fully sensible of our individual responsibility. Seeing that the study of the relations between capital and labour involve the consideration of the complex problems of existence, the solution of which is at present hidden from us, we shall feel with Andrew Lang that 'where, as matter of science, we know nothing, we can only utter the message of our temperament.' My own leads me to hope that the patriotism of the workmen will prevent them from driving our national industries from these shores, and I would ask those to whom the direction of the metallurgical works of this country is confided, to remember that we have to deal both with metals and with men, and have reason to be grateful to all who extend the boundaries, not only of our knowledge, but also of our sympathy.

The following Reports were read :

1. Report of the Committee on International Standards for the Analysis of Iron and Steel.-See Reports, p. 273.

2. Report of the Action of Light upon Dyed Colours.-See Reports, p. 263.

3. Report on the Influence of the silent discharge of Electricity on Oxygen and other Gases.-See Reports, p. 264.

4. Report on the Bibliography of Solution.-See Reports, p. 273.

5. Report on the Properties of Solutions.-See Reports, p. 273.

6. Report on the Bibliography of Spectroscopy.-See Reports, p. 264.

FRIDAY, AUGUST 21.

The following Report and Papers were read :—

1. Report of the Committee on the Formation of Haloids.
See Reports, p. 274.

2. The Spontaneous Ignition of Coal. By Professor VIVIAN B. LEWES.

Ever since Berzelius first suggested that the heat evolved by the oxidation of the pyrites in coal might have an important bearing on spontaneous ignition, it has been adopted as the popular explanation of that phenomenon, and although the researches of Richter and others have gone far to disprove it, this theory is the generally accepted one. It can be shown, however, that the coals most liable to spontaneous ignition often contain as little as 0.8 per cent. of pyrites, and rarely more than 2 per cent., and if this amount were concentrated in one spot, instead of being spread over a very large mass, and if it were entirely oxidised with the greatest rapidity, instead of taking months and often years to complete the action, the total rise of temperature would be totally inadequate to account for ignition of the coal, which requires a temperature of 370° C. to 477° C., according to its characteristics. The liability to spontaneous ignition also does not increase with percentage of pyrites, whilst heaps of pure pyrites free from carbonaceous matter never show any tendency to serious heating.

The true explanation of the ignition of coal is partly physical and partly chemical. Freshly won coal has the power of absorbing from 15 to 3 times its volume of oxygen from the air, and this being rendered chemically highly active, partly by compression and partly by elimination of nitrogen, attacks some of the bituminous hydrocarbons in the coal, converting them into carbon dioxide and water vapour. Many causes tend to affect the rapidity of this action, which is the real source of the heat, and directly the temperature begins to rise, unless the heat evolved can freely diffuse itself, the chemical action is so energetic that ignition quickly follows. Up to 38° C. the absorption of oxygen, and consequent chemical action, goes on so slowly that there is little or no chance of undue heating; but directly this temperature is exceeded, with some classes of coal ignition is only a question of time and mass. The action of mass, condition, and temperature can be beautifully traced in the statistics of spontaneous ignition in coal cargoes, whilst the bunker fires, which are now becoming perilously frequent on the fast liners, are due entirely to rise in temperature from the bunker bulkheads being too close to the hot air up-cast shafts from the boilers and furnaces.

3. On Nickel Carbon Oxide and its Application in Arts and Manufactures. By LUDWIG MOND, F.R.S.

The existence of a volatile compound of nickel and carbonic oxide was first discovered in the author's London laboratory in October, 1889, in the course of an

TRANSACTIONS OF SECTION B.

investigation on which he was engaged with his assistants, Dr. Carl Langer and Dr. Friedrich Quincke, into the remarkable property of metallic nickel to induce, at the comparatively low temperature of 350° C., the complete dissociation of carbonic oxide into carbon and carbonic acid, which, according to Victor Meyer and Carl Langer, by the application of heat alone remains incomplete at a temperature of 1,690° C.

A very small quantity of nickel can effect the dissociation of a large quantity of carbonic oxide, and becomes converted into a very voluminous black mass containing varying quantities of carbon up to 85 per cent. This mass takes fire on exposure to air, so that it had to be cooled with exclusion of air for the purpose of analysis, which was done in a slow current of carbonic oxide gas. This gas was subsequently led into a Bunsen burner, so as to keep it out of the atmosphere of the room. In this way it was observed that when the cooling had proceeded to a certain point (about 150°C.) the Bunsen flame became luminous and remained so, and even became intenser, down to ordinary atmospheric temperature. When the gas before entering the burner was heated in a glass tube, a metallic mirror was obtained, while the luminosity of the flame disappeared.

At first this phenomenon was referred to the presence in the nickel of an unknown element, perhaps to Krüss and Schmidt's Gnomium, which at this time still haunted chemical literature. The metal of the mirror, however, gave all and every one of the reactions of nickel with remarkable brilliancy, and an approximate determination of the atomic weight came out so nearly to the very carefully determined figure of Russel for nickel (58.58 as compared with 58.74) that there could be no doubt about its identity with our well-known old friend, whose character as a simple body, called in question by Krüss and Schmidt, was thus rehabilitated.

In repeating the experiment with carbonic oxide, quite free from hydrogen and moisture, and only contaminated with nitrogen, the same result was obtained. After removing the carbonic oxide by cuprous chloride and heating the residual contained gas to 180° in aniline vapour, at which temperature nickel, quite free from carbon, is separated, the volume of the gas expanded considerably, and the gas only nitrogen and carbonic oxide. It was thus evident that a volatile compound of nickel and carbonic oxide had been obtained, which, on heating, dissociated into its constituents. The increase of volume proved that one volume of gas yielded four volumes of carbonic oxide, and the determination of the amount of nickel deposited and the carbonic oxide formed led to a proportion of four equivalents of carbonic oxide to one of nickel. To further study the properties of this compound it was necessary to produce larger quantities, which took a long time to accomplish. By preparing the nickel in a very fine state of division, at the lowest possible temperature, by reducing the oxide, or, better still, the oxalate, in a current of hydrogen at about 400° C., and by carefully purifying and regulating the current of carbonic oxide, the compound was formed quite readily, and the gas passed through a refrigerator, cooled by ice and salt, was condensed to a liquid.

This liquid is colourless, mobile, highly refracting, possesses a characteristic odour, and is very volatile. It is soluble in a large number of organic liquids, such as alcohol, ether, chloroform, benzole, petroleum, tar oils, &c. It boils at 43° C. and 751 mm. pressure without decomposition, and evaporates rapidly at ordinary temperatures in a current of other gases. The specific gravity is 1.3185 at 17° Č.; at -25° it solidifies, forming needle-shaped crystals; the pure vapour explodes when suddenly heated to above 60°, and even when the tube containing it is scratched roughly with a file. A mixture of the vapour with air explodes violently on the application of a flame. Both the liquid and the vapour are poisonous, the latter approximating carbonic oxide in this respect. According to an investigation kindly undertaken by Professor McKendrick, the liquid dissolved in chloroform produces, when injected subcutaneously in extremely small doses in rabbits, an extraordinary reduction of temperature, amounting in some cases to 12° C.

Careful determinations of the quantity of nickel contained in the liquid, made by introducing a weighed quantity into chlorine water and precipitation of the nickel from the resulting solution, led to figures agreeing very closely with the