TECHNICAL CHEMISTRY. 319 



acid from 100 of sulphur is practically considered about 

 the proper production, so that, taking the theoretical yield 

 to be 306 parts, the average loss would be about five per cent, 

 of sulphur. In cases where special precautions are taken, 

 the yield reaches 297 parts, but not unfrequently, I am 

 afraid, much less careful working is observed, and large 

 escapes of sulphurous fumes then occur. Thus in his Eighth 

 Annual Report (1871) Dr. R. Angus Smith, the well-known 

 chief government inspector of alkali-works, gives (p. 17) 

 a table, showing the total escape of sulphur acids., (calcu- 

 lated as sulphuric acid) from twenty-three chemical works. 

 From this it appears that whilst from some of the works 

 no escape of these acids occurs, the average loss of sulphur 

 in the twenty-three works in question is 7*606 per cent, on 

 the total quantity burnt, and that the loss in the case of 

 four works actually rises to more than 20 per cent., in one 

 case amounting to an escape of 159 Ibs. of sulphuric acid 

 every hour. "Facts like these," says the inspector, 

 " dispose of the argument often used by the manufacturers, 

 that they require the acid, and that it is to their interest 

 to keep it, and of course condense it to the best of their 

 power. Indeed certain makers are fully aware that they 

 are allowing sulphuric acid to escape in large quantities, 

 but their reply is that it is cheaper to permit a large 

 escape, and work rapidly, rather than have large chambers, 

 and condense the whole of their gases." Hence there can 

 be no two opinions as to the desirableness of compelling 

 such makers to work properly, and an extension of the 

 Alkali Act (which now, so far as a definite limit is concerned, 

 only applies to hydrochloric acid) to the sulphur acids seems 

 to be imperatively called for in the interests of the nation. 



Through the kindness of several eminent manufacturers 

 I am able to give a practical test of the performance of the 

 process in different works in England and on the Continent. 

 Thus Messrs. Gaskell, Deacon, and Co. of Widnes find as 

 a result of eighteen months' work, including stoppages, &c., 

 during that time, that one cubic metre of chamber space 

 takes 5*74 kilos of sulphur per week, producing 15 '9 8 

 kilos of strong sulphuric acid (H 2 S0 4 ). It is to be re- 

 membered, however, that if the working is measured only 

 for one day, when all is in good order, this number would 

 be materially raised. At the works of Messrs. Muspratt 



