Ixxiv PROCEEDINGS. 



weakly acid solution, or send a small sample to me when I would be 

 pleased to report the presence or absence of the earths. If the suspected 

 mineral contains Di. a direct vision spectroscope will detect it at once by 

 pimply looking through it at the mineral. Now, finally, to give a little 

 attention to what, according to my heading, ought to be the most 

 important part of my paper. Why are the rare earths of especial 

 importance to the chemical world ? Why did such a chemist as Kriiss 

 give up so much of his too-soon ended life to their study? Why do 

 Brauner, Wilson, Cleve, Boisbaudren, Debray, Crookes, and scores of 

 lesser lights give all the time they can spare to solve the mystery? Why 

 did Crookes, when a few pounds of Sipylite, so far a rare mineral, were 

 found not long since in Texas, cable to reserve it all for himself at any 

 price 1 Why did chemists like Marignac and Bunsen in the latter part 

 of their life, with all their vast accumulations of scientific knowledge and 

 their tried analytical skill, give their finest work to the unravelling of 

 this problem? For two reasons chiefly. The desire to discover the 

 truth, the aim of every true scientist, coupled with the knowledge that 

 here was a field to test the mettle of the bravest and ablest, but also, 

 and perhaps more important for proving the falsity of, or on the other 

 hand, rounding out the periodic system of the elements. 



The scientist ever seeks to bring the subject which he studies under 

 the power of mathematics. lie recognizes that this is the most power- 

 ful of instruments with which to work. All branches of science have, 

 however, to pass the observational stage before laws can be deduced and 

 classifications brought about. Though several chemical facts can be 

 discussed mathematically, the subject as a whole is but emerging from the 

 observational stage. Botany is still in this stage as also Bacteriology, the 

 latter, of course, far behind the former ; and possibly it may be claimed 

 that the former is nearer mathematical control than chemistry. Its 

 classification is certainly superior, but its classification, at least the one 

 now in use, is a superficial one and readily arrived at. Not so Chemistry. 

 The atom and even the molecule, evades our grasp and laughs at our skill, 

 the balance alone conquers them and even here we grasp them but 

 lightly. Their existence, even, is being disputed so evasive are they, 

 and those who would claim their existence are confronted by metaphysi- 

 cal reasonings to prove them only hallucinations. It has been a long 

 and weary search since Dalton propounded his atomic theory but the 

 reward seems nearer. Thompson, or I should say Lord Kelvin, is fixing 



