waniing and exhortation of one of the gi'eat chieftains of art and 

 science, — I mean Dr. Lyon Playfaii- : — " Practice and science must now 

 join together in close alHance, or the former will soon emigi-ate to other 

 lands. The time is past when practice can go on in the blind and vain 

 confidence of a shallow empiricism^ severed from science like a tree from 

 its roots. The rudest sailor may steer his ship in the du-ection of a land 

 mai-k, but without compass and sextant he does not traverse the expanse 

 of ocean. Ignorance may walk in the path dimly lighted by advancing 

 knowledge, bi.it she stands in dismay when science passes her, and she 

 is unable to follow, like the foolish virgin having no oil in her lamp. 

 Depend upon it, an empirical knowledge of practice is not the way now 

 to succeed in the struggle of individuals, or in the struggle of nations. 

 Intellect is on the stretch to get forward, and that nation which holds 

 not by it will soon be left behind. For a long time, pi"actice, standing 

 still in the pride of empiricism, and in the ungrateful forgetfulness of 

 what science has done in its development, reared upon its portal the old 

 and vulgar adage that 'an ounce of practice is worth a ton of theory.' 

 This wi-etched inscription acted like a Gorgon's head, and turned to 

 stone the aspirations of science. Believe it not ; for a grain of theory, 

 if that be an expression for science, will, when planted, like the mustard 

 seed of scripture, grow and wax into the greatest of trees. The pressure 

 and difficulties of the age, and the rapid advancement of intellect in 

 continental nations, have been the PerseiTS to cut off this Medusa's head 

 from the industry of England, and to fix it on the shield of Minerva, who 

 turns to stone those that believe that science should be ignored by 

 practice ; but, reversing her shield, wisely conducts such as are willing 

 to go further under her guidance. It is now rare to find men who 

 openly avow, although they actually entertain, a belief in a necessary 

 antagonism between theory and practice. Theory is in fact the ru.le, 

 and practice its example. Theory is but the attempt to furnish an 

 intelligent explanation of what is empirically ascertained to be true, and 

 is always useful, even when wrong. Theories are the leaves of the tree 

 of science, bringing nutriment to the parent stem while they last, and 

 by their fall and decay affording the materials for the new leaves which 

 are to sticceed." 



