THE PRESIDENT'S ADDRESS. 447 



would not have you go away with the impression that I advocate 

 such studies solely on account of immediate practical good to be 

 derived from them. Far from it. I am one of those who hold 

 so-called theoretical and unpractical studies to be of the highest 

 importance, and worthy of all support, if only for the reason 

 that, being unremunerative, they often cannot support them- 

 selves. All history shows us that the knowledge of general 

 principles must precede their application and practice, and that 

 what is purely theoretical in one generation becomes thoroughly 

 practical in the next or in a later one. There is no need for me 

 to waste your time by multiplying instances of this familiar 

 truth. But I will conclude with a few words on the wider 

 applications of microscopy. 



In the range of the natural sciences, two branches of knowledge 

 stand at opposite poles, as judged from the standpoint of the 

 objects with which they deal. The science of astronomy deals 

 with the infinitelv great: the science of biolosjv, on the other 

 hand, with the infinitelv small. The astronomer with his 

 telescope astounds us with the distant worlds he reveals to us ; 

 he thinks in millions of miles as ordinary persons deal with feet 

 •or yards ; and he exhibits to us this world on which we live as 

 but an insignificant planet, one of many, whirling round a star 

 far inferior in magnitude to many of those we see nightly, a tiny 

 speck in the vast ocean of space and matter, peopled by a race of 

 puny creatures who style themselves the lords of creation, although 

 their dominion does not extend over a billionth part of the 

 universe. " The consciousness of an endless series of worlds," 

 said Kant, " destroys my sense of importance, making me only 

 one of the animal creatures which must return its substance 

 again to the planet (that, too, being no more than a point in 

 space) from whence it came, after having been in some unknown 

 way endowed with life for a brief space." 



Not less astounding, but in a totally different way, are the 

 revelations of the biologist with his principal instrument of 

 research, the microscope. With this he discovers continually 

 new worlds invisible to the unassisted eye, and reveals infinite 

 •complexity in things apparently the most simple. We find, 

 in the first place, our own bodies to be microcosms, small worlds, 

 that is, of such inexhaustible variety and elaboration of detail 

 that to the human mind they are as difficult to comprehend and 



