756 THE POPULAR SCIENCE MONTHLY. 



municated to others. Speaking for myself as one who in a special 

 sense entered into his labors, I should find it difficult to express ade- 

 quately my feeling of obligation. 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 univer- 

 sal 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 " Le Malade Imaginaire," who explains the 

 fact that opium sends you to sleep by its soporific virtue. Maxwell's 

 endeavor was always to keep the facts in the foreground, 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 rediscovery in the library may be a more diffi- 

 cult and uncertain process than the first discovery in- the laboratory. 

 In this matter we are greatly dependent upon annual reports and ab- 

 stracts, issued principally in Germany, without which the search for 

 the discoveries 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 investigator 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 the 

 laborious accumulation of facts, it would soon come to a stand-still, 

 crushed, as it were, under its own weight. The suggestion of a new 

 idea, or the detection of a law, supersedes much that had previously 

 been a burden upon the memory, and by introducing order and coher- 

 ence facilitates the retention of the remainder in an available form. 

 Those who are acquainted with the writings of the older electricians 

 will understand my meaning when I instance the discovery of Ohm's 

 law as a step by which the science was rendered easier to understand 

 and to remember. Two processes are thus at work side by side, the 

 reception of new material and the digestion and assimilation of the 

 old ; and, as both are essential, we may spare ourselves the discussion 

 of their relative importance. One remark, however, should be made. 



