496 Sir W. Boberts-Austen [Feb. 22, 



WEEKLY EVENING MEETING, 



Friday, February 22, 1901. 



Sir Andrbw Noble, K.C.B. F.E.S., Vice-President, in the Cbair. 



Sir W. Roberts-Austen, K.C.B. D.C.L. F.E.S. M.B.L 



Metals as Fuel. 



A careful metallurgist,* writing in the eighteenth century, claimed 

 that "every matter which is combustible either wholly or in part, is 

 called fuel, the pabulum of fire." The word is, however, usually 

 restricted to substances which may be burnt by means of atmo- 

 spheric air with sufficient rapidity to evolve heat capable of being 

 applied to economic purposes. The latter definition covers certain 

 metals, though it was doubtless framed to include only carbon and 

 associations of carbon and hydrogen, such as coal. The omission 

 from the definition of the reference to atmospheric air would enable 

 the list of metals which might be used as fuel to be widely extended. 



It has long been known that metals will burn, and it would be 

 easy to show that the history of inorganic chemistry is epitomised 

 and enshrined in a mass of litharge, which is simply burnt lead. 

 Successive generations of chemists, from Geber in the eighth century 

 to Lavoisier in the eighteenth, studied litharge carefully before the 

 latter proved partly by its aid the identity of respiration, calcination 

 and combustion. Into this history I need not enter, but it may be 

 pointed out that Sir Isaac Newton f had a clear idea as to the possi- 

 bility of burning metals. " Is not fire," he asks, " a body heated so 

 hot as to emit light copiously ?"..." for what else is red-hot iron 

 than fire ? " and he significantly adds, " metals in fusion do not flame 

 for want of copious fume." He was, moreover, aware that a mixture 

 of lead and tin " suitably heated " does emit " fume and flame," and, 

 in fact, a mass of one part tin and four parts lead, which looks 

 metallic, will, if it be kindled, continue to burn like an inferior 

 variety of peat, leaving an ash-like product which may be used as 

 an enamel. 



I propose to show that metals may be burnt for the sake of the 



* C. E. Gellert, ' Metallurgic Chemistry,' translated by I. S. (London, 1776), 

 p. 74. 



f ' Optic,' pp. 316-319, quoted by Shaw in his edition of the works of Boyle, 

 vol. ii. p. 400. 



