212 Centenary Commemoration, 1799-1899. [June 7, 



Wednesday, June 7, 1899. 



His Grace the Duke of Northumberland, E.G., President, 

 in the Chair. 



COMMEMOEATION LECTURE, 



By Professor Dewar, M.A. LL.D. F.R.S. M.B.L, 

 Fullerian Professor of Chemistry M.I. 



There were also present, the Honorary Members, together with 

 Lord Kelvin, Lord Amherst, Sir George Stokes, Sir Andrew Noble, 

 Dr. Ludwig Mond, Sir James Crichton-Browne, Sir Frederick 

 Bramwell, Bart., Sir Frederick Abel, Bart., Sir William Crookes, 

 and Lord Rayleigh. 



Professor Dewar said : — 



My colleague, Lord Rayleigh, in his Commemoration Lecture, 

 dealt so admirably and exhaustively with some of the discoveries of 

 our great predecessors in this Institution, that it will be unnecessary 

 to pursue further the lines of historical treatment in this lecture. 

 Instead of discoursing generally on the chemical side of the work 

 of Davy and Faraday and their successors, it has seemed to me more 

 appropriate to attempt some experimental demonstrations of the 

 latest modern developments in a field of inquiry opened out to 

 science by the labours of the two illustrious chemists just mentioned. 

 With this object in view, my discourse this evening will be confined 

 to the subject of liquid hydrogen. Davy said : " Nothing tends so 

 much to the advancement of knowledge as the application of a new 

 instrument. The native intellectual powers of man in different times 

 are not so much the causes of the different success of their labours 

 as the peculiar nature of the means and artificial resources in their 

 possession." The new instrument of research, which, for the first 

 time we have to experiment with before an audience, is the liquid 

 form of the old inflammable air of Cavendish. Lavoisier towards the 

 end of the last century had the scientific acumen to declare that in 

 his opinion, "if the earth were suddenly transported into a very cold 

 region, the air, or at least some of the aeriform fluids which now 

 compose the mass of our atmosphere, would doubtless lose their 

 elasticity for want of a sufficient temperature to retain them in that 

 state. They would return to the liquid state of existence and new 

 liquids would be formed, of whose properties we cannot at present 

 form the most distant idea." Black, about the same time, in dis- 

 cussing the properties of hydrogen, makes the following suggestive 

 observations : " We may now further remark with regard to inflam- 

 mable air, that it is at present considered as one of the simple or 

 elementary bodies in nature. I mean, however, the basis of it, called 

 the Hydrogen by the French chemists ; for the inflammable air itself, 

 namely, hydrogen gas, is considered as a compound of that basis 



