eight per cent. of the element present in the waste may now be recovered by modern processes. Scarcity of sulphur, therefore, need not be apprehended. But our production of nitre is absolutely nil; and it is to this constituent of gunpowder that attention would have to be devoted.

less powder. The remainder are either | recovery of the sulphur from the alkali too sensitive to allow of safe transport, wastes, with the result that ninetyor are too local in their action; and are entirely unfit to take the place occupied so long by the oldest of all explosives gunpowder. Assuming, then, that for naval and military purposes a supply of either cordite or gunpowder is indispensable, the question arises and it is one of considerable importance Supposing our ports were blockaded for any lengthened period, and our supplies thus cut off, should we be able to maintain the necessary stock of explosives ?

At present, we are entirely dependent upon foreign materials for the manufacture of these bodies. Of the ingredients used in making gunpowder - namely, charcoal, sulphur, and nitre (potassium nitrate), the first-named is the only one obtained in this country, both the sulphur and nitre being imported. Similarly in the case of cordite, which is a mixture of gun-cotton, nitro-glycerine, and vaseline, we again rely upon foreign sources for the necessary materials. Thus the nitric acid used in making the nitro-glycerine and gun-cotton is all manufactured from sodium nitrate imported from Chili and Peru; the vaseline is obtained from the United States. It is well worth considering, then, what we should do if thrown by invasion upon our own resources, in order that the requisite substances might be produced in sufficient quantity.

Coming to cordite, and taking its constituents separately: the gun-cotton is made from cotton waste by the action of nitric acid in the presence of concentrated sulphuric acid. In case of extremity, cotton rags of any description, or even fibres of wood, could be used instead of the cotton waste. The sulphuric acid is made from our own natural productions. The nitric acid — made from foreign sodium nitrate would be the ingredient for the production of which efforts would have to be directed. So with nitroglycerine, which is made by acting upon glycerine with nitric acid and strong sulphuric acid. Our soap-works could supply an abundance of glycerine; but we should again be faced with the necessity of making the nitric acid. The third body used in making cordite - namely, vaseline could be replaced if necessary by some of the heavy oils obtained by distilling coaltar or shale. So that in the case of our smokeless powder, as in that of gunpowder, the difficulty would be found in obtaining the nitrogen compound.

these. Thus, picric acid- variously known as melinite, lyddite, etc.— is made by acting upon phenol with nitric acid; nitro-benzene by treating benzene with nitric acid; and so on.

On examining in detail the materials Even if some of the more feasible of required to manufacture these explo- the other explosives known could be sives, it will be found that the chief pressed into service for use in our orddifficulty would be to obtain a supply of nance, the same contingency would the nitrogen compounds used nitre still confront us, as nitric acid is essenin the case of gunpowder, and nitric tial to the manufacture of almost all of acid in that of cordite. Taking gunpowder: the charcoal would always be forthcoming; sulphur — of which there are vast quantities locked up in our minerals - could be procured in abundance by resorting to chemical proc- These two nitrogen compounds esses. Indeed, at the present time nitre and nitric acid — without which sulphur is one of the most important none of our explosives could be made, by-products at all alkali works where are easily convertible one into the the Leblanc method is practised. Great other. Given either, the second could attention has been bestowed upon the be readily produced; and if any means

were known by which one of them any appreciable and useful quantity of

could be obtained, the question would be solved. It would be interesting, therefore, to consider the possible ways by which this end could be secured.

the necessary nitrogen compounds could be produced by their means. The first of these depends on the fact, that when a hydrogen flame is burnt In spite of the advances made in in a mixture of oxygen and air, some chemical science, we are as yet ac- nitric acid is formed during the comquainted with only one process by bustion. If this were performed on a which nitre may be made directly in large scale, there is little doubt that useful quantities. It was adopted by considerable quantities of nitric acid the French during the Revolution, could be obtained, and from it the nitre when their coasts were blockaded, and could be made. But at the best, this their supply of nitre for making powder process is cumbersome and expensive, ran short. No improvement or devel- and the quantity of nitric acid produced opment has yet been made upon the is very small in proportion to the simple though tedious method then amount of hydrogen consumed. It used, which is as follows: Heaps of would certainly be the last method remanure were allowed to rot in the dark sorted to, unless it could be vastly for some months, after which the ashes improved. Recently, however, an inof plants were scattered over the fer-teresting means of producing nitric mented heap, which was moistened acid has been discovered by Crookes. occasionally with stable runnings. The It is undoubtedly capable of great exwhite crust which appeared on the mass after a time-consisting chiefly of nitrates of calcium and magnesium was removed, and boiled with potash lyes, upon which it decomposed, yielding an impure nitre, which was purified by recrystallizing. Recently, Pasteur and Warington have investigated the formation of nitrates in manure-heaps, and have found that the nitrogen contained in the organic matter is converted into nitric acid by small organisms. When plant-ashes are placed on the mass, this nitric acid combines with the lime and magnesia present in the ashes, forming their re-supply of nitric acid could not be spective nitrates. readily and cheaply obtained in this manner.

Having regard, however, to the slowness of the method and the greater expenditure of explosives in modern warfare, it is doubtful whether sufficient material could be thus provided; and we should in all probability have to bring in the aid of other processes to serve as auxiliaries to the foregoing. Of these, notwithstanding the fact that the elements contained in nitric acid are present in limitless quantities in air and water, only two have been discovered, and each of these would require considerable development before

tension, and if properly worked out, would in all probability supersede the present methods for making this acid. Crookes found that when a powerful, rapidly alternating current of electricity was passed through a Tesla induction coil, the poles of which were placed beyond sparking distance, the air between the poles could be lighted like ordinary coal-gas, clouds of nitric acid vapor being produced by the burning. This discovery is of the greatest importance; and if the process were extended so as to work on a very large scale, there is no reason why a large

Such, then, are the methods, at present imperfect, upon which we should be compelled to rely in the event of a sustained invasion of our islands. It is to be hoped that in the near future either they will be made more expeditious, or some better means of producing the requisite nitrogen compounds will be devised, and so furnish these ingredients in such quantity that no drawback could possibly be experienced through lack of explosive materials under any circumstances.

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Is that no sense of being disappears
Or fails- I see the signal, hear the call-

And distance, heart to heart despairing Can calmly estimate the rise and fall

From The Edinburgh Review. ADAM SMITH AND HIS FRIENDS.1

Thus it

ing known to us the man.
happens that one hundred and five
years after his death Mr. Rae presents
the public with the first complete biog-
raphy of Adam Smith that has seen
the light.

MORE than a century has elapsed since the death of Adam Smith, but as yet the world at large has had little opportunity of making itself acquainted with the personality of an individual It seems a long time since the year who has left upon it such deep and en- 1740, when Adam Smith began his unduring marks. The great economist dergraduate life at Oxford. Yet before kept no journal at any period of his his death he became intimate with the life. He was little addicted to writing poet Samuel Rogers, who was himself letters. He insisted, only a week be-intimately known to many of our own fore his death, upon his friends de- contemporaries the bridge of a single stroying the whole of the manuscripts life thus connecting two periods suffiwhich he had left in an unfinished con- ciently remote from each other in much dition. Hence, for many long years besides length of years. there were but few materials out of Mr. Rae in the preparation of his which it would have been possible to work has shown both industry and construct with any kind of fulness the judgment; and we believe he has story of his life. As time has gone on, been able to collect and weld together biographies of his contemporaries, and all the published information which memoirs and letters in great number, exists having any important bearing have been published in which some upon Adam Smith's career. In his mention, more or less incidental, of undertaking, however, he has not conAdam Smith has been made, and it has tented himself with searching works become possible by piecing them to- already published; he has made congether and by making full use of the siderable use of the Hume correspondearlier biographical sketches, to pre-ence in the possession of the Royal sent the public with a connected ac- Society of Edinburgh; of the Carlyle count of his whole career, from the correspondence, and the David Laing time when he attended as a little lad manuscripts in the library of the Unithe burgh school at Kirkaldy, to the versity of Edinburgh; he has examday of his death in Edinburgh, one of ined every mention of Adam Smith in the most renowned literary personages the records of the University of Glasof Europe. No complete life, then, of gow and the buttery books of Balliol. Adam Smith has ever yet been pub- He has had access to many private lished. The fullest account of his letters, and information bearing upon career is still to be found in the essay Adam Smith's career, in the possession which Dugald Stewart read on his life of Professor Cunningham of Belfast, and works to the Royal Society of of Mr. Alfred Morrison, and others, Edinburgh only a couple of years after and he shows himself to be well acSmith's death. Mr. McCulloch and quainted with the memoirs and biogMr. Thorold Rogers, in publishing new editions of the "Wealth of Nations," have prefixed to that epoch-making work some account of the author's life, but they were able to add little to the particulars given by Dugald Stewart. Lord Brougham, whose "Lives of Men of Letters" was published in 1846, in his chapter on "Adam Smith," devoted himself rather to the discussion of the works of the philosopher than to mak1 The Life of Adam Smith. By John Rae.

London 1895.

raphies, English and foreign, dealing with the second half of the eighteenth century, where many incidental references and allusions to the philosopher are to be found. The result of his labors is now before us in the very complete picture he has drawn of Adam Smith and his social surroundings in the latter half of the last century.

Adam Smith was born at Kirkaldy in June, 1723. His father, Adam Smith, had been trained as a writer to the sig net, and had been appointed immedi