Ne. 7.] WURTZ— THEORY OF ATOMS. 375 



Mechanics, physics, chemistry, physiology itself, have fouud at 

 once a point d'appui and a bond of connection. And this power- 

 ful flight of ideas has been sustained by the progress of the me- 

 thods, I should say by the more careful exactness of observations, 

 the perfect delicacy of experiments, the more rigorous severity 

 of deductions. These are the springs of this movement which 

 hurry along the sciences, and of which we are the astonished and 

 moved witnesses. It is to propagate it broadcast over our country 

 that we hold, each year, this parliament, to which are invited all. 

 who take part or are interested -in the war against the unknown. 

 Science is indeed a war against the unknown ; for, if in literature 

 it is enough to give expression, and in art a body, to conceptions 

 or beauties deposited either in the human mind or in nature, it 

 is not so in science, where truth is deeply hidden. She must be 

 conquered, she must be stolen, like the Promethean fire. 



It is of some of these conquests that I wish to speak to-day, 

 full of doubt and apprehension in presence of so great a ta.sk. To 

 respond to the demands of his position and to follow noble exam- 

 ples, your president ought, at the beginning of this session and 

 of the ceremonies which inaugurate our young association, to 

 trace the progress accomplished in the sciences, mark by a few 

 bold lines the various routes over which it has recently run, and 

 the culminating points which it has attained. I shrink from such 

 a programme : if it does not exceed the powers of some of my 

 -colleagues, and doubtless of some among you, it greatly surpasses 

 mine. Less justified and less daring than was Condorcet at the 

 end of last century, I only perceive the outlines und some bright 

 patches of the sketch whicli he attempted to draw; and to see it 

 accomplished, I shall call to my assistance those who will follow 

 me in the honourable and perilous post I now occupy. 



I shall confine myself, then, gentlemen, to speaking to you of 

 what I know, or of what I think I know, by directing your at- 

 tention to the science to which I have devoted my life. 



Chemistry has not merely grown, it has been regenerated since 

 Lavoisier. You know the work of that immortal master. His 

 labours in connection with combustion gave to our science an 

 immovable basis by fixing at once the notion of simple bodies 

 and the essential character of chemical combinations. In these 

 latter we find in weight all that is ponderable in their elements. 

 These, in uniting to form compound bodies, do not lose any of 

 their proper substance ; they lose only an imponderable thinij, 



