LAUGEL'S PROBLEMS OF NATURE AND LIFE. 319 



ness. M. Laugel enters into these questions, and we 

 give the following passage as a good example of his 



style : 



' La force est ce qu'il y a de plus mysterieux dans la 

 nature. Elle est dans la substance et n'est pas la substance ; 

 ou plutot la substance etant perpetuellement active et passive, 

 en tant que passive elle subit Faction de la force, en tant 

 qu'active elle devient force a son tour. Car il ne faut point 

 imaginer la force comme quelque chose d'exterieur a la 

 matiere ordinaire, comme une entite d'une espece particuliere 

 qui se melerait aux corps, y entrerait, en sortirait, au gre des 

 circonstances. Avant qu'on eut bien compris le caractere dc 

 1'universalite de la force, telle etait 1'idee qu'on se faisait des 

 forces particulieres. On parlait du fluide electrique, du 

 calorique, dela gravite, comme d'essences reelles, sur-ajoutees 

 en quelque sorte a la matiere. Le langage de la physique 

 n'est pas encore debarrasse de ces locutions vicieuses.' 



M. Laugel here and elsewhere shows the intrinsic 

 difficulties of the subject, but provides no new or 

 feasible way out of them. The science of our day has 

 instructed us largely, though yet imperfectly, in the 

 atomic and molecular properties of matter ; and in 

 those multiform changes by addition, subtraction, and 

 substitution on which chemistry, as a special branch of 

 knowledge, is founded. But it tells nothing of that 

 secret motive cause on which these changes depend, 

 and by which they are translated from one portion of 

 matter to another, under exact equivalents of power 

 and effect. 



It is not surprising that this problem of force, as 

 grand as obscure, presenting itself in naked form even 

 to the rudest intelligence, should have been seized 

 upon with avidity in all ages. Some of the questions 



