president's address — SECTION B. 121 



cent, brought the coke from 9 per cent, to only 7 per cent. At the 

 same time no matte separated out. Gruner, therefore, concluded that 

 the iron was oxidised, and acted as a fuel. But Percy (r) contended 

 that, in the reducing atmosphere of the furnace, this oxidation was 

 impossible. At the present time one would be inclined to subscribe to 

 the former. 



It was Bode (s) who, in 1872, in a pamphlet devoted to the manu- 

 facture of sulphuric acid, combated the idea, then still current, that 

 the amount of heat liberated in the combustion of sulphide substances 

 was directly commensurate with their sulphur contents, and calculated 

 the pyrometric intensities developed by 15 different sulphide minerals 

 and mattes, his special object being, however, merely to lay stress on 

 the oxidation of the metallic bases, and to prove that the compounds 

 were capable of self-supporting calcination. Nevertheless, the most 

 important step towards the recognition, that the temperatures sufficed 

 for smelting purposes also, was thus at last taken. 



Six years later John Hollway drew the last conclusion that was 

 to be drawn from all the foregoing, and courageously brought to both 

 a theoretical and practical focus the pyritic principle thus gradually 

 instilled in the professional mind, and gave it a definite metallurgical 

 expression and existence. This is not the place to go into a recital of 

 his elaborate large-scale trials. Suffice it to say that they were made 

 with the use of low-grade Rio Tinto pyrites at Messrs. Cammell & Co.'s 

 steel plant in 1878-9, the ordinary Bessemer paraphernalia being em- 

 ployed. The pyrites was melted down in a cupola furnace, and blown 

 in regular 6-ton vessels with 201bs. air pressure. All phenomena were 

 scientifically scrutinised, temperatures, flame, composition of gas and 

 molten products, &c. Among other things Mr. Hollway succeeded in 

 running one converter on pyrites and quartz for 14 consecutive hours, 

 with repeated charging, and with the total exclusion of carbonaceous 

 fuel other than that used to provide the blast. Altogether his trials 

 demonstrated to the members of the Society of Arts, for whose benefit 

 a special exhibition was given, as well as to the world at large, that 

 pyrites carrying copper could be made self-smelting, and was a 

 metallurgical fuel of the utmost efficiency ; that the waste of its fuel 

 qualities, which was being incurred in the current process of prepara- 

 tory treatment by calcination, could be obviated ; that a high rate 

 of concentration of copper tenor was achievable ; that a complete 

 utilisation of the atmospheric oxygen was effected, &c. Mr. Hollway's 

 essay (t) on the results of these trials is one of the classics 

 of modern metallurgical literature, and his experiments them- 

 selves are a brilliant contribution to the annals of empirical 

 research along this line of work. He availed himself of the 

 Bessemer plant chiefly as a matter of convenience, and was 

 convinced that it was unsuitable because of its intermittent operating 



(r) " The Metallurgy of Lead," London, 1870, p. 349. 

 (s) F. Bode, " Beitrage zur Theorie u. Praxis der Schwefelsaure-fabrication," 



Hanover, 1872. 

 (1) Read befoie the Society of Arts on February 12th, 1879 ; title cited above. 



