612 BUNSEN MEMORIAL LECTURE. 



whole of the heat thus allowed to escape might without difficulty be 

 utilized for the various purposes of the worlds. These sug-oestions 

 were only slowly adopted by the ironmasters; six years ehipsed before 

 any steps in the direction indicated were taken, but gradually the 

 importance of the proposal was appreciated, and now and for many 

 years past the whole of th(> hitherto wasted heat has been utilized and 

 economies eft'ected of which the value may be reckoned ))v millions 

 rather than by thousands of pounds. 



Not only is it the lost heat which has been recovered, but also valu- 

 able by-products, the existence of which had l)een up to that time 

 entirely ignon^d. The report ])()ints outthc^ loss of coml^ined nitrogen, 

 l)oth as ammonia and cyanogen, which the process as then carried out 

 evolves, the upper part of the furnace being, in the words of the report, 

 ■"'a region of distillation and not of combustion." The amount of loss 

 of thesi' valuable mat»'rials was asc(M-taii;;'d by accurate analysis, aiid 

 a method for recovering them suggested, *' without increasing the cost 

 of manufacture or in the slightest degree afiecting the process of snx^lt- 

 ing." Apropos of the determination of the escaping c3'anogen com- 

 pounds, the occurrence of a singular accident to Bunsen, as related by 

 Playfair. is found in the admirabh^ life lately written by Wemyss 

 lieid: " Bunsen was engaged below," at the blast furnaces at Alfreton, 

 in Derbyshire, ""and I above, passing the gases through water to col- 

 lect any solul)le products, when I was alarmed by being told that my 

 friend had become suddeidy ill. I ran down and saw white fumes 

 coming out of a lateral tul)e, and Bunsen apparently recovering from 

 a fainting condition. I a])])li(>d my nose to the oi'ifice and smelt the 

 vapor of cyanide of potassiuiu, which gave an entirel}' new light to 

 the processes of the furnace." 



In 1857 Bunsen collected in a volume — the only book he ever pub- 

 lished — the whole of his gasometric researches, and of this a second 

 and greatly enlarged edition appeared in 1877 (Gasometric Methods, 

 by K. W. Bunsen. translated by II. E. Roscoe, 1857). No better or 

 more complete method of learning what Bunsen's work is like can be 

 taken than that of reading this volume. For originality of conception, 

 for success in overcoming diiiiculties, for ingenuity in the construction 

 of apparatus, and for accurate work, I believe the book, as a record of 

 experiment, to be unequaled. 



The first part contains a description of his various processes for col- 

 lecting, preserving, and measuring gases, different methods being 

 employed for the first of these according to the source from which the 

 gases are obtained, whether, as has been described, from blast furnaces 

 or from fumeroles, from volcanic vents or when freely rising from 

 mineral springs, or whether the gases are contained in solution in river 

 or spring water. In the second part we find a full description of the 



