410 Dr. Faraday on the Diamagnetic conditions 



appeared to do the same ; at all events it did not pass off 

 equatorially. But as there was reason, from the above expe- 

 riments with nitrogen, to expect that oxygen would appear, 

 not diamagnetic but magnetic in air; so the place of the 

 stream was changed and made to be on one side of the 

 axial line. In this case it fell perfectly well at first into a 

 catch-tube placed beneath ; but as soon as the magnet was 

 rendered active, the stream was deflected, being drawn towards 

 the axial line, and fell into another catch-tube placed there to 

 receive it. So oxygen appears to be magnetic in common air. 

 Whether it be really so, or only less diamagnetic than air (a 

 mixture of oxygen and nitrogen), we shall be better able to 

 consider hereafter. 



Hydrogen. — This gas proved to be clearly and even strongly 

 diamagnetic ; for notwithstanding the powerful ascensive force 

 which its stream has in the atmosphere, because of its small 

 specific gravity, still it was well deflected and sent equatorially. 

 Considering the lightness of the gas, one might have expected 

 that it would have been drawn towards the axial line, as a 

 stream of rarefied air (if it could exist) would be. Its dia- 

 magnetic state, therefore, shows in a striking point of view, 

 that gases, like solids, have peculiar and distinctive degrees of 

 diamagnetic force. 



Carbonic acid. — This gas made a beautiful experiment. 

 The stream was delivered downwards a little on one side o 

 the axial line; a catch-tube was placed a little further out, so 

 that the stream should fall clear of it as long as there was no 

 activity in the magnet. But on rendering the magnet efficient, 

 the stream left its vertical direction, passed equatorially, and 

 fell into the catch-tube; and by looking horizontally, could 

 be seen flowing out at its lower extremity like a spring, and 

 falling away through the air. Again, the magnet was thrown 

 out of action, and a glass with lime-water placed beneath the 

 lower end of the catch-tube ; no carbonic acid appeared there, 

 though the fluid in the glass was continually stirred; but the 

 instant the magnet was made, the carbonic acid appeared in 

 the catch-tube, fell into the glass and made the lime-water 

 turbid. This gas therefore is diamagnetic in air. 



Carbonic oxide. — This gas was carefully freed from carbonic 

 acid before it was used. It was employed as a descending 

 stream, and was apparently very diamagnetic : but it is to be 

 remarked, that a substance which is so nearly the specific gra- 

 vity of atmospheric air is easily dispersed right and left in it, 

 and therefore that the facility of dispersion is not a correct 

 indication of the diamagnetic force. By introducing a little 

 ammonia into the mica chamber, it was, however, easily seen 



