472 



NATURE 



[December 31, 1914 



to our resources in this direction which as yet 

 are but little known, and interesting to many as 

 a discussion of the novelty and advantages of 

 these would be, it would be impossible to do 

 justice to the subject without occupying far more 

 space than is available. Dr. Knott's chapter on 

 the abacus, also, is one which it would be de- 

 lightful to follow if only space allowed, for the 

 description of the mental process followed by the 

 Japanese when making their lightning speed 

 calculations with the abacus, of their inverse way 

 of effecting division, and, in general, of the man- 

 ner in which they work off figure by figure the 

 problem set upon the abacus as it is done with to 

 make room for the new figure in the result; all 

 are full of interest, and a careful study of this 

 chapter would be likely to modify the complacency 

 with which the European in general contemplates 

 the Asiatic as a computer with wires and beads. 



C. V. Boys. 



on. OF VITRIOL AS AN AGENT OF 

 "CULTURE." 

 The Manufacture of Sulphuric Acid and Alkali 

 with the Collateral Branches : a Theoretical and 

 Practical Treatise. By Prof. G. Lunge. Fourth 

 edition. Vol. i. : Sulphuric Acid, Part i., pp. 

 xxiv + 582. Part ii., pp. xii + 583-1078. Partiii., 

 pp. xii+ 1079-1617. (Gurney and Jackson, 

 1913.) Price, vol. i. (in 3 parts), 3Z. 35. net. 



PROF. LUNGE'S monumental work on the 

 manufacture of sulphuric acid is one of the 

 acknowledged classics of chemical technology, and 

 the soundest proof of its continued merit and 

 widespread appreciation is seen in the circum- 

 stance that it has now reached its fourth edition. 

 The subject is admittedly of great complexity. 

 The manufacture is one of the great staples of 

 chemical industry, and lies, in fact, at the basis 

 of that industry in general. 



Indeed, it is impossible to conceive of the posi- 

 tion of chemical industry, and of the industries 

 dependent upon it, if the world were suddenly 

 bereft of sulphuric acid. If we could deprive 

 Germany, for example, of all means of manufac- 

 turing or otherwise procuring oil of vitriol, not 

 only would her chemical industries languish, but 

 even her capacity for military offence or defence 

 would be effectually checked since the use of 

 this acid is indirectly, but nevertheless absolutely, 

 necessary for the manufacture of those high explo- 

 sives upon which her artillery, the strongest arm 

 of her service, wholly depends. She has, of 

 course, internal means of supply, but these are by 

 no means limitless, and there are already signs 

 that she is within measurable distance of the end 

 of her resources as regards the provision of the 

 NO. 2357, VOL. 94] 



raw materials needed for the manufacture. Liebig 

 once said that we might gauge the civilisation of 

 a country by the amount of this acid it consumed. 

 It would appear, therefore, that the continued 

 forcible dissemination of German "culture" is 

 largely dependent upon a German supply of oil 

 of vitriol. 



But, of course, it is the arts of peace that 

 mainly consume the oil of vitriol the world re- 

 quires, and there is scarcely a process of manu- 

 facture that could be named that does not need it 

 either directly or indirectly. 



It is difficult to obtain a trustworthy estimate of 

 the aggregate output at the present time, but from 

 the statistics referred to by Dr. Lunge it is prob- 

 ably not fewer than five million tons, of which not 

 less than a fifth, and probably more, were, prior 

 to the outbreak of war, made in Germany, mainly 

 from imported iron pyrites. 



In addition, Germany has hitherto imported a 

 gradually increasing quantity of oil of vitriol, 

 amounting in 191 1 to 99,653 tons. At the present 

 time, therefore, she is almost wholly dependent 

 upon the employment of zinc-blende, the relatively 

 poor German pyrites, the mixed ores from Frei- 

 berg, and Man sf eld, and the small quantity from 

 gas-oxide. It may be anticipated, therefore, that 

 the serious economic disturbance consequent upon 

 the invasion of her eastern frontier will very 

 largely affect her ability to maintain her supply. 



In the case of a substance of such world-wide 

 application as sulphuric acid it need scarcely be 

 said that there is a very strenuous industrial com- 

 petition, and there is probably no branch of 

 chemical technology which has been more thor- 

 oughly developed than its manufacture, and to-day 

 its production is studied, watched, and controlled 

 with all the precision of a vast scientific experi- 

 ment in which all the resources of modern 

 cherrucal, physical, mechanical, and engineering 

 knowledge are brought to bear. The main prin- 

 ciples of its manufacture are in all probability 

 definitely established, but so fierce is the competi- 

 tion and so bountiful the trained skill and intelli- 

 gence concentrated upon its economic production, 

 that each succeeding decade sees some new depar- 

 ture, often of fundamental or far-reaching import- 

 ance. It is a duty which the veteran author has 

 imposed upon himself in the days of his retirement 

 from the active work of his professorship, to take 

 note of these changes, and to embody them in 

 successive editions of the great work with which 

 his memory will always be associated. That he 

 may long be spared to continue this self-imposed 

 task is the sincere hope of every well-wisher to 

 the progress of that great branch of technology 

 of which Dr. Lunge has been for so many years 

 so distinguished an exponent. T. 



