MICHAEL FARADAY — HIS LIFE AND WORKS. 243 



other erases are diamagnetic. Considering the great part taken l)y oxygen in 

 the composition of our atmosphere, he attempted to explain, by the magnetic 

 properties of this gas combined with variations of temperature, the phenomenon 

 of the diurnal variations of the magnetic needle which he traced over all parts 

 of the surface of the globe. It is impossible for us not to regret a little the 

 consideralile time which he devoted to this investigation, especially as it appears 

 to us very probalde that it is not in the action of the atmos])here, l)ut much 

 rather in that of the earth itself, or perhaps even in that of the sun, that we 

 must seek the cause of all the j^henomena presented by the magnetic needle. 



Lastly, a third point remains to be noticed, namely, that which relates to the 

 investigation of the magnetic field and of what Faraday denominates the lines 

 of magnetic force. According to him, as we have already had occasion to 

 remark, there is no such thing as action at a distance ; consequently the mag- 

 netic field (that is to say, the space included between two approximated mag- 

 netic poles, such as those of a horseshoe magnet) is a medium from which, in 

 every one of its points, forces emanate, the distribution and direction of which 

 are indicated by the ver}^ regular arrangement effected by fine iron-filulgs 

 placed in this space. The lines which he calls lines of magnetic force thus 

 become visible and even tangible. But they exist none the less even when we 

 cannot see them, and it is the displacements or modifications which they expe- 

 ■ rience by the presence of a ponderable body in the medium in which they occur 

 that give rise to all the remarkable effects of which the magnetic field is the 

 scene. Such is, in a few words, Faraday's Anew upon this particular question. 



We pass in silence over a multitude of interesting details upon diamagnetic 

 polarity, upon the distinction to be set up between magnetic and diamagnetic 

 bodies, and upon the possible relation between gravity and electricity. In 

 L850 Faraday reverted to this question, which he had previously attempted, but 

 without success. We see that it is with regret that he is obliged to relinquish 

 the discovery of this relation, which he had twice sought after ; but with his 

 usual good faith he admits that, although convinced that it exists, he was una- 

 ble to find any fact to establish it. If experiment, which he knew so well 

 how to employ constantly, gave him a negative response, would not this be 

 because his point of view was not con*ect ? and did not his error arise from his 

 forming too vague ideas as to the transfonnation of forces, not taking suffi- 

 ciently into account that it is the work ejffected by the force, and not the force 

 itself, that must be considered in questions of this kind ? 



V. We have passed in review the principal labors of Faraday ; and it only 

 remains for us, in order to complete this notice, to endeavor to form an idea of 

 the special character of these labors, and of the influence which they have 

 exerted on the progress of science. 



The first character that strikes us is their number. What Faraday published 

 in the form of memoirs, fi-om 1820 to 1855, is incredible. And what would it 

 have been if, side by side with the multitude of experiments wliich he has made 

 known, Ave placed in a parallel series those which he never published *? It is 

 trae that if he has left them buried in his journal, it is because they gave him 

 negative results ; but from how many fruitless essays and erroneous attempts 

 he would have preserved scientific men if he had not been so discreet ! 



A second character is the exactitude of the results obtained : I do not think 

 that Faraday has once been caught in a mistake ; so precise and conscientious 

 was his mode of experimenting and observing. It must be admitted that iu 

 him the hand marvellously seconded the head ; he was of remarkable dexterity, 

 and possessed a practical talent, rare and precious in men of science, which 

 enabled him, when necessary, to construct and modify his apparatus for himself, 

 with the view of attaining with more certainty the desired result. 



A third character, of quite a different kind and of much greater value, is the 

 originality of the works of Faraday. A disciple of Davy, he undoubtedly 



