NA TURE 



381 



THURSDAY, JULY 12, 1917. 



ACIDS AND THE WAR. 

 The Manufacture of Sulphuric Acid and Alkali, 

 with the Collateral Branches. . A Theoretical 

 and Practical Treatise. By Dr. G. Lunge. 

 Fourth edition. Supplement to vol. i., Sulphuric 

 and Nitric Acid. Pp. xii4-347. (London: 

 Gurney and Jackson, 1917.) Price 155. net. 



THE veteran professor emeritus of the Federal 

 Technical University of Zurich would seem 

 to be devoting his well-earned leisure almost 

 exclusively to the emendation of those monu- 

 mental treatises on chemical technology with 

 which his name is so honourably associated. 

 Scarcely four years have elapsed since he brought 

 out the fourth edition of his well-known work on 

 "The Manufacture of Sulphuric Acid and 

 Alkali," and it has now become necessary to 

 issue a supplementary volume dealing more par- 

 ticularly with sulphuric and nitric acids. 



The crisis through which the world is now 

 passing has led to an extraordinary extension in 

 the manufacture of these substances. Here, as 

 in other matters, necessity has been the mother 

 of invention. Some old processes, it is true, 

 have been resuscitated, but far more new and 

 original ones have been devised. Some of these 

 are only vaguely known, as, for obvious reasons, 

 few details have been allowed to transpire. It 

 is, of course, too soon to speak with confidence 

 concerning their ultimate fate. The times are 

 so utterly abnormal that all ordinary economic 

 considerations are thrown aside. Sulphuric and 

 nitric acids must be had ; they are absolutely neces- 

 sary to the national existence of all the 

 belligerents, and if the usual sources of supply 

 are not available or are insufficient, other or addi- 

 tional means must be found. To the nations 

 which have more or less ready access to the sea 

 the conditions are not so strenuous as they 

 undoubtedly are to the Central Powers, and it is 

 in the latter case that the new developments 

 referred to have been most marked. Many out- 

 side sources of sulphur, pyrites, and nitrates were 

 quickly cut off from Germany and Austria, and 

 there is no doubt that at one period in the history 

 of the war they were threatened with collapse 

 owing to a shortage of these materials. The 

 inventive genius of their chemists, however, 

 would appear to have surmounted this crisis, and 

 the world has been informed on high authority 

 that Germany, and presumably also Austria, are 

 no longer under any apprehension that the supply 

 of their munitions is in jeopardy from this cause. 

 As regards these matters, it is scarcely to be 

 expected that Dr. Lunge is able to afford much 

 information. We shall have to wait for the con- 

 clusion of hostilities to learn what permanent 

 changes have been effected in this branch of 

 manufacturing chemistry in Central Europe. 

 But, so far as can be foreseen, they will probably 

 not be very profound, at least as regards prin- 

 ciples. The stress of competition will tend, as 

 hitherto, to approximate methods to a standard 

 NO. 2489, VOL. 99] 



and practically uniform type. In this respect 

 history will repeat itself. Under the pressure of 

 necessity many processes have had to be 

 adopted in war-time which are promptly 

 abandoned when peace is resumed and the world's 

 markets are once more available. At the same 

 time experience gained under such conditions is 

 bound to have a profound influence on the 

 development of chemical technology. The war 

 has had a tremendous "hustling" effect upon 

 chemical manufactures of all kinds and in all 

 countries in which this industry has any import- 

 ance. All the portents go to show that the 

 Germans are becoming nervously apprehensive 

 that their pre-eminence in certain directions is 

 now seriously assailed. There was a time when, 

 for example, in the matter of synthetic dyestuffs, 

 they treated the rest of the world with con- 

 temptuous indifference. The annual reports of 

 such a powerful combination ^s the Badische 

 Company are now couched in very different terms 

 from those which prevailed prior to 19 14. They 

 no longer have an uncontrolled command of over- 

 sea markets, and they realise that fact. 



Dr. Lunge's new volume is, as its title states, 

 strictly supplementary. It corrects any errors 

 which may have been detected in the last edition, 

 and adds such new matter as may have been 

 published in the ordinary technical journals since 

 191 2-1 3, or which may have been communicated 

 to the author from private sources. It consists 

 practically of a series of notes, each of which 

 starts with the number of the page in the main 

 work to which the note refers, or to which it 

 may be regarded as an appendix. In general 

 arrangement, therefore, it follows strictly the 

 plan of the larger work. Dr. Lunge is evidently 

 a most assiduous reader of the literature of 

 chemical technology, and nothing relating to 

 those branches of manufacture with which he 

 has been more immediately concerned seems to 

 escape his notice. His study is a veritable 

 clearing-house in regard to such subjects, and 

 what he fails to note is probably scarcely worth 

 noting. Indeed, if he errs at all, it is, perhaps, 

 that his chronicle is too full ; he occasionally 

 notices, with a meticulous care, things which have 

 no abiding place in technology', and which even the 

 most receptive of practical men would willingly 

 let die. Still, if it is a fault, it is an error in 

 the right direction, which all who appreciate his 

 zealous and long-continued services in the cause of 

 chemical technology will gladly condone. T. 



THE HEAT TREATMENT OF STEEL IN 



PRACTICE. 

 Steel and its Heat Treatment. By Denison K. 

 BuUens. Second impression, with additions. 

 Pp. vii + 441. (New York: J. Wiley and Sons, 

 Inc. ; London : Chapman and Hall, Ltd., 1916.) 

 Price 175. 6d. net. 



T^HE heat treatment of steels is an art of recent 

 -*- growth. Twenty years ago it could scarcely 

 be said to exist. Such as it was. it usually con- 

 sisted in "heating to a red heat " for annealing, 



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