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THE subject chosen for this occasion is a very large one and for its complete treatment would require many evenings. It will be neceseary, therefore, to select a few of the more important from the several lines of thought which suggest themselves. Partly on this ground, therefore, I have not attempted to enter into the economic features of the questions relating to the industrial applications of chemis ry, and how they are to be succoured and sustained under the conditions prevailing after the conclusion of the war. I have also referred only in general terms to the way in which chemistry should be taught and to the conditions under which scientific chemists may assist manufacturing operations. Though many students of chemistry are present there are many others among the audience who are unacquainted with chemistry, and for their benefit I shall therefore begin by sketching in the briefest possible manner the main features of the history of the science. It is perhaps scarcely realised by many persons, even students of chemistry, how completely it belongs, as a systematic branch of physical science, to modern times. This consideration becomes vivid in my own mind when I reflect that in the early days of my own grandfather, whom I knew personally, as he died long after I was grown up, the composition of air and water was unknown. Oxygen was discovered by Priestley in 1774, the composition of water was determined by Cavendish in 1781, and subsequently the nature of the process of combustion and the influence of air in respiration, in the rusting of iron and other natural processes, were first correctly explained by Lavoisier. The chief epochs following the time of Lavoisier may be bri.fly enumerated as follows:-The first twenty years of the nineteenth century witnessed the wonderful discoveries of Sir Humphry Davy and the introduction of the Atomic Theory by John Dalton. This theory has furnished the framework of all chemical theory since that day. Then followed the work of Faraday, to whom chemistry is indebted not only for the discovery of benzol, but especially for the establishment of the laws relating to electrolysis or electro-chemical decomposition. The composition of so-called "organic" compounds such as sugar, alcohol, and acetic acid was not known with certainty much before 1830, and the question as to the composition and constitution of organic substances of all kinds was the chief subject of debate from that time onward for some forty years. With regard to the elements and their simpler compounds, the law of periodicity among atomic weights discovered by John Newlands in 1864, and subsequently established and developed by the great Russian chemist, Mendeléeff, has been the guiding principle down to the present day. With regard to useful applications of chemistry, it may be stated that there were no manufactures based on chemical principles before the discovery of the compostion of air and water and the nature of the process of burning. For ages various chemical arts had been practised. Thus, the mummy cloths and remains of glass vessels to be seen in the British Museum prove that the arts of the Decembes, 1916. 37 dyer and glass maker were practised long before the Christian Era. Soda and soap were also made by crude processes, and several metals were extracted from their ores, but in no case was the relative chemical change understood. Let us look at the history of the two chemical substances which supply the keys to nearly all the products of chemical manufacture, namely, sulphuric acid and soda. Sulphuric acid was originally made by distilling green vitriol, and in the concentrated form still goes by the alchemical designation oil of vitriol. But it was observed long ago, that when sulphur is burned a small quantity of the same acid is produced, and an accidental observation led to the discovery that when sulphur is deflagrated with a little nitre, a large quantity of acid is produced. This method was used in the early part of the eighteenth century, and to facilitate the mixture of the fumes on a larger scale, Dr. Roebuck, of Birmingham, introduced the use of a chamber made of sheet lead, and he set up works at Preston Pans in Scotland in the year 1749. The product was known as English oil of vitriol, but no further improvements were possible till the general nature of acids, bases, and salts had been explained by Lavoisier. Then in the nineteenth century the chambers were greatly enlarged, and the first definite improvement in the form of the Gay-Lussac tower was introduced. This method of manufacturing sulphuric acid will probably be superseded in time by the modern contact process. The history of soda is somewhat similar. Originally obtained wholly from the ash of sea-weeds, and especially of certain plants growing near the sea, soda in the eighteenth century found its way into commerce chiefly in the form of what was known as barilla from Spain. But during the war at the end of the eighteenth century Spanish barilla was excluded from France. The French Government accordingly offered a prize for the invention of a process by which soda (the carbonate) could be made from common salt, then largely extracted from sea-water in the neighbourhood of Marseilles. The result was the introduction of the "black-ash" process by Nicholas Leblanc, who set up the first a.kali works in 1804. Leblanc's process was largely adopted in Lancashire and on the Tyne, and during the former half of the nineteenth century sulphuric acid and soda were supplied to almost all the world by England. It may safely be asserted that, without the knowledge of saline compounds and their constitution provided by Lavoisier, the chemical transformation of sodium chloride into sodium carbonate would never have been accomp ished, or even attempted. extracts. The supply of dye-stuffs provides another instance of the application of the same principle. Previously to 1856 the dyes required, whether for application to silk, wool, or cotton were obtained almost entirely from vegetable materials such as woods, barks, berries, or Everyone has heard of madder, logwood, indigo, and the French purples made by macerating certain lichens in ammonia. To these must be added one important dye of animal origin, namely, cochineal. This consists of the bodies of insects which are cultivated in Mexico, the Canary Islands, and other tropical regions. It does not seem long since the British army was clothed in scarlet derived from cochineal. But in 1856 the first of the now extensive series of coal-tar colours, namely aniline purple, or mauve, was discovered by the late Sir William Henry Perkin. Many persons now living can remember the magnificent display of crystallised colouring matters, especially the crown shaped frames covered with magenta, which appeared in the International Exhibition of 1862. They can also remember the talk at that time, and for some years later. of the huge dividends being paid by the great firm of English colour-makers, Messrs. Simpson, Maule, and Nicholson. To realise the predominant position of England in regard to chemical manufactures fifty years ago, it is only necessary to refer to the Reports of the Juries, in |