6S 



NATURE 



[March 27. 19 19 



pected demand on her resources occasioned by 

 a strug'g'le of such magnitude as that in which 

 she was involved. The Germans began the war 

 in the confident behef that the resources of all 

 their enemies would be either quickly ex- 

 hausted, or incapable of full , utiUsation before 

 the lightning-stroke they contemplated should 

 have determined the issue. They will learn the 

 extent of their miscalculation, at least as regards 

 sulphuric acid in this country, should they care 

 to study the figures which the Committee now 

 makes known. 



The actual consumption of sulphuric acid in 

 Great Britain before the war is not known w-ith 

 certainty, as no detailed statistics are available, 

 but the Committee has been at pains to collect 

 information from authorities, and gives the fol- 

 lowing table showing approximate estimates of 

 the annual pre-war consumption by the more 

 important trades : — 



Tons 100 per cent. Tons equivalent 

 acid per annum chamber acid 



Superphosphates ... 300,000 450,000 



Sulphate of ammonia ... 280,000 420,000 

 Bleaching powder, hydro- "| 



chloric acid, alkali, and J- 186,000 279,000 



alum J 



Iron pickling ... ... 70,000 105,000 



Recovery of grease ... 20,000 30,000 



Copper sulphate ... 25,000 37,ooo 



Dyeing and bleaching... 25,000 37,ooo 



Dyes ... ... ... Very small — 



Oil refining 20,000 30,000 



Explosives 30,000 45, 000 



"Iron pickling " refers to the use of the acid in 

 the tinplate and galvanising trades, and " recovery 

 of grease " to its employment in connection with 

 the treatment of wool-washing liquors, etc., in 

 the textile trades. These figures, although admit- 

 tedly only approximate, are valuable as showing 

 the relative distribution of the main amount of 

 sulphuric acid produced in this country. It will 

 probably be news to many people that consider- 

 ably more than half is needed for the manufacture 

 of fertilisers. 



In addition to the trades mentioned, sulphuric 

 acid is' used in a numher of minor industries, but 

 no exact estimate can be formed of the aggregate 

 amount. The Committee is probably within the 

 mark in assuming that the annual production in 

 the British Isles before the war was about 

 1,000,000 tons of 100 percent, acid, or 1,500,000 

 tons of chamber acid. It considers that this 

 quantity may also be taken as the national con- 

 sumption, since both the export and import of 

 sulphuric acid were; negligible in amount. 



Sulphuric acid goes into industry of several 

 degrees of strength, by far the largest amount 

 being used in the form of "chamber acid " — that 

 is, as produced directly in the lead-chambers, and 

 without subsequent concentration. The concen- 

 trated acid of 95 per cent, strength was produced 

 to. the extent of 75,000 tons. What is known as 

 "contact acid" or oleum amounted to about 

 22,000 tons per annum. It is used mainly in the 

 manufacture of explosives and dyes, and was pro- 

 duced only by three firms. 



NO. 2578, VOL. 103] 



No estimate of the actual amount of sulphuric 

 acid employed for munitions since 1914 is fur- 

 nished by the Committee, but some idea of its 

 magnitude may be gained from certain figures 

 adduced by them to show the post-war position of 

 the industry after allowing for a reversion to- 

 normal working conditions. 



Oleum 

 Chamber 



Pre war Post-war 



(Tons 100 per cent, acid perannuin)j 



22,000 450,000 



,040,000 1,265,00©' 



1,062,000 



1,715,000 



Equivalent chamber 

 acid ... 1,593,000 2,572,000 I 



It will be seen that the amount of "oleum " — 

 the variety of special importance in the manu- 

 facture of munitions — increased more than twenty- 

 fold in the course of the war, and mainly during 

 the last two or three years of it. But a consider- 

 able amount of concentrated chamber acid was 

 also gained by restricting supplies to manufac- 

 turers of superphosphates and to certain other 

 trades. Large oleum plants were erected by the 

 Government in connection with its explosive- 

 factories, and the productive capacity of the plant 

 either owned or leased by the Ministry of Muni- 

 tions is estimated by the Committee at 315,000 

 tons 100 per cent, acid, equivalent to 472,000 tons 

 chamber acid, per annum, or rather less than half 

 the gross estimated surplus. 



In its previous report the Committee con- 

 sidered what steps might be taken to safeguard 

 the sulphuric acid industry after the war in view 

 of the position created by it. Not only has a large 

 amount of new and valuable plant been erected 

 — more than peace conditions can utilise — but a 

 further extension of the industry is imminent,, 

 owing to the prospective development of zinc pro- 

 duction in this country, and the consequent neces- 

 sity for dealing with the sulphurous acid produced 

 in roasting the concentrates. Some time before 

 jthe war Herr Hasenclever, a well-known German 

 chemical manufacturer, in the Hurter lecture to 

 one of the sections of the Society of Chemical 

 Industry, pointed out what had been the result 

 on the price of sulphuric acid of the action of the 

 German Government in compelling the zinc manu- 

 facturers of Silesia to condense their acid fumes 

 — an admitted necessity. It is quite evident from 

 the tenor of its report that the Committee is 

 apprehensive of a similar result here. There is 

 likely to be a glut of sulphuric acid and a serious 

 depreciation of prices for some time to come 

 unless plant is scrapped or shut down. The most 

 obvious remedy is a great extension of the fer- 

 tiliser industry, but this is not immediately pos- 

 sible, unless there is a more rapid development 

 of the by-product coking industry, and a conse- 

 quent increase in the production of ammonia, and 

 larger available supplies of mineral phosphates. 

 The Committee, of course, recognises this fact, 

 and in its present report it makes this addi- 

 tional recommendation : " That the Government 

 should take immediate steps by international com- 



