BUNSEN MEMOEIAL LECTURE. 611 



the cheraical changes which occur in the processes of a most inip-.i-tant 

 industry, that of the production of cast iron in the l)last furnace. 



The first detailed description of Bunsen's gasonietric methods was 

 published in pamphlet form by Kolbe, who was at the time one of 

 Bunsen's assistants. To the English public these methods lu'came 

 known by a communication made to the meeting of the British Asso- 

 ciation at Cambridge in 1845 by R. W. Bunsen and Lyon Phiyfair, 

 entitled ''On the gases evolved from iron furnaces with reference to 

 the smelting of iron." Before entering upon the technical side of the 

 question, the authors give experimental proofs concerning the accuracy 

 and reliability of the methods employed for the measurement and the 

 separation of the blast-furnace gases. One of these consisted in the 

 analyses of a large number of samples of air. These were collected 

 and analyzed in Marbui-g, and gave analytical results upon which Bun- 

 sen reports as follows: 



''The close agreement of these experiments with one another, and 

 with the result obtained by the careful experimental determination of 

 the composition of air by Dumas, proves that the eudiometric exam- 

 ination of gases admits of a degree of exactness which is certainly not 

 surpassed by the most minute chemical methods, and they further show 

 that the presence of nitrogen does not exert an\' disturbing iuliuence 

 on the estimation of explosive mixtures of gases." 



The report, printed in full in the British Association volume for 1845, 

 next proceeds to discuss the experiments made bj- Bunsen on the com- 

 position of the gases evolved in the process of iron smelting in fur- 

 naces fed with charcoal and using cold ))last at Vickerhagen. in Ger- 

 many. From these, it appeared that in such furnaces nearly half the 

 heat of the fuel consumed was evolved in the escajjing gases. 



The importance of these investigations, as being the tirst attempt to 

 introduce accurate scientific inquiry into so widespread an industry as 

 that of iron smelting, was at once appreciated by Lyon Tlayfair, who 

 had made Bunsen's acqua intance at Marburg. In consequence, at Play- 

 fair's suggestion, Bunsen consented to visit England, and undertook to 

 carry out a similar set of experiments for the English furnaces fed 

 with coke and coal, and worked l)oth by hot and by cold blast, to those 

 which he had previously made in Germany. Ihus was initiated a 

 research which may be truly said to te a model of the application of 

 the methods of scientific investigation to the elucidation of industrial 

 problems. For not only did it clearly reveal the nature of the chemi.al 

 changes which take place throughout the furnace, but pointed out the 

 direction in which economies to an undreamt-of extent might he 

 efiected in the processes as then carried on. Thus it proved that u hde 

 about half the fuel was lost as escaping gas in the Genua.. turnac.;s, 

 no less than 81.5 per cent was lost in English ones, and. what ssas 

 important from the industrial point of view, it pointed ..ut that the 



