484 Canadian Record of Scsence. 



" Seek ye first the kingdom of God and its right- 

 eonsness and all these things shall be added unto you." 

 That is a truth which applies in other spheres than 

 that of religion. The man who says to himself, " Go 

 to now, let us discover something useful," rarely 

 discovers anything. The inventor is the man who 

 applies the principles discovered by the student of 

 pure science, so that if the study of pure science were 

 to be discouraged, the practical applications would soon 

 cease also. This may seem to some of my hearers 

 rather a bold statement. I think, however, that I can 

 justify it by giving a few examples : — 



Take a discovery that is exciting the greatest 

 interest at the present time, and that promises 

 results of the most far-reaching importance, viz., wire- 

 less telegraphy. Let us trace the apostolical succes- 

 sion, to borrow a term from theology, of the idea 

 which underlies this discovery. Thirty or forty years 

 ago, the great Cambridge physicist. Clerk Maxwell, 

 one of the greatest and most penetrative of the 

 geniuses who have filled the chairs of that ancient 

 University, was engaged in determining the value of 

 the electrical unit. As many of my hearers are aware, 

 there are two ways of doing this : • we can estimate 

 either the push that an electric charge exerts on 

 another similar charge, or else the pull that an electric 

 current effects on a magnetic needle. In this way, 

 two different values for the unit are arrived at, and 

 the relation between them, or to put it more simply, 

 the number obtained by dividing the one by the other, 

 gives the velocity of light in centimetres per second. 

 This remarkable result suggested to Clerk Maxwell 

 that that mysterious thing called electricity had some- 

 thing to do with the ether which fills all space and 



