RayleigKs Address to the British Association. 109 



upon the present state of science, we must regard not only the 

 work that he executed himself, important as that was, but also 

 the ideas and the spirit which he communicated to others. Speak- 

 ing for myself, as one who in a special sense entered into his labors, 

 I should find it difficult to express adequately my feeling of obliga- 

 tion. The impress of his thoughts may be recognized in much 

 of the best work of the present time. As a teacher and examiner, 

 he was well acquainted with the almost universal tendency of 

 uninstructed minds to elevate phrases above things ; to refer, for 

 example, to the principle of the conservation of energy for an 

 explanation of the persistent rotation of a fly-wheel, almost in the 

 style of the doctor in "La Malade Imaginaire," who explains 

 the facts that opium sends you to sleep by its soporific virtue. 

 Maxwell's endeavor was always to keep the facts in the fore- 

 ground, and to his influence, in conjunction with that of Thomson 

 and Helmholtz, is largely due that elimination of unnecessary 

 hypothesis, which is one of the distinguishing characteristics of 

 the science of the present day. 



In speaking unfavorably of superfluous hypothesis, let me not 

 be misunderstood. Science is nothing without generalizations. 

 Detached and ill-assorted facts are only raw material, and, in the 

 absence of a theoretical solvent, have but little nutritive value. 

 At the present time, and in some departments, the accumulation of 

 material is so rapid that there is danger of indigestion. By a 

 fiction as remarkable as any to be found in law, what has once 

 been published, even though it be in the Russian language, is 

 usually spoken of as " known," and it is often forgotten that the 

 re-discovery in the library may be a more difficult and uncertain 

 process than the first discovery in the laboratory. In this matter 

 we are greatly dependent upon annual reports and abstracts, issued 

 principally in Germany, without which the search for the discover- 

 ies of a little-known author would be well-nigh hopeless. Much 

 useful work has been done in this direction in connection with 

 our Association. Such critical reports as those upon Hydro- 

 dynamics, upon Tides and upon Spectroscopy, guide the inves- 

 tigator to the points most requiring attention, and in discussing 

 past achievements contribute in no small degree to future progress. 

 But though good work has been done, much yet remains to do. 



If, as is sometimes supposed, science consisted in nothing but 



