INSTRUMENTS AND METHODS OF RESEARCH 201 



and many of you, doubtless, were this an experience meeting, could 

 easih' occupy the balance of the evening in delightful recollections 

 of what each has found best to stimulate him to renewed intellectual 

 activity; and I dare say tliat many of you would unite with me in de- 

 claring that membership in this society has been one of the most help- 

 ful and stimulating influences. 



We really have much to be proud of in the history and membership 

 of the Philosophical Society of Washington. I should, indeed consider 

 myself remiss in the duties imposed upon me by the subject selected 

 did I not refer at least to the eminent part this society, through its 

 members, has taken in bringing about the wonderful appreciation of 

 scientific work and scientific methods we are to-day witnessing in our 

 country. There have been several notable addresses by past presidents 

 that might advantageously have been reviewed in connection with our 

 topic. But we lack the time. 



I cannot refrain, however, from quoting once more from Henry's 

 address, already referred to, which I hope you may be induced to read 

 in its entirety : 



Man is a sympathetic being, and no incentive to mental exertion is more 

 powerful than that which springs from a desire for the approbation of his fellow- 

 men; besides this, frequent interchange of ideas and appreciative encouragement 

 are almost essential to the successful prosecution of labors requiring profound 

 thovight and continued mental exertion. . . . 



It is an essential feature of a scientific society that every communication 

 presented to it should be subject to free critical discussion. Such discussion not 

 only enlivens the proceedings, but is generally instructive, frequently eliciting 

 facts which, thovigh insignificant when isolated, when brought together mutually 

 illustrate each other and lead ultimately to important conclusions. 



Conclusion 



My address began with statements revealing the necessity of keep- 

 ing our minds ever open and free for the careful weighing and the un- 

 biased reception of the facts observed and discovered. Throughout I 

 have attempted to lay chief sti*ess upon the mental and human elements 

 involved in the topic. I can not do better in closing than to quote 

 you a sentence from a letter^ which the great mathematical physicist, 

 James Clerk Maxwell, wrote to Herbert Spencer on a subject of con- 

 troversy in the latter's " First Principles," viz. : 



It is very seldom that any man who tries to form a system can prevent 

 his system from forming around him, and closing him in before he is forty. 

 Hence the wisdom of putting in some ingredient to check crystallization and keep 

 the system in a colloidal condition. 



Let our watchword therefore be: ever to Tceep our systems — our 

 theories — in a colloidal condition! 



""Life and Letters of Herbert Spencer," by David Duncan, Vol. II., p. 163. 

 VOL. LXXIV. — 14. 



