On the hifluence of Eleclro-magnetism upon 'Flame. 421 



for us in a most satisfactory manner. But where the trne 

 zero is, or that every body is more or less removed from it on 

 one side or the other, is not, as yet, experimentally shown or 

 proved. 



I cannot conclude this letter without expressing a hope that 

 since gases are shown to be magnetically affected, they will 

 also shortly be found, when under magnetic influence, to have 

 the power of aff'ecting light (Experimental Researches, 2186, 

 2212). Neither can I refrain from signalizing the very re- 

 markable and direct relation between the forces of heat and 

 magnetism which is presented in the experiments on flame, 

 and heated air and gases. I did not find on a former occasion 

 (Experimental Researches, 2397) that solid diamagnetic 

 bodies were sensibly affected by heat, but shall repeat the ex- 

 periments and make more extensive ones, if the Italian philo- 

 sophers have not already done so. In reference to the effect 

 upon the diamagnetic gases, it may be observed that, speaking 

 generally, it is in the same direction as that of heat upon iron, 

 nickel and cobalt ; /. e. heat tends in the two sets of cases, 

 either to the diminution of magnetic force, or the increase of 

 diamagnetic force; but the results are too few to allow of any 

 general conclusion as yet. 



As air at different temperatures has different diamagnetic 

 relations, and as the atmosphere is at different temperatures 

 in the upper and lower strata, such conditions may have some 

 general influence and effect upon its final motion and action, sub- 

 ject as it is continually to the magnetic influence of the earth. 

 I have for the sake of brevity frequently spoken in this 

 letter of bodies as being magnetic or diamagnetic in relation 

 one to another, but I trust that in all the cases no mistake of 

 my meaning could arise from such use of the terms, or any 

 vague notion arise respecting the clear distinction between 

 the two classes, especially as my view of the true zero has 

 been given only a page or two back. 



I am, my dear Sir, 



Yours, &c., 

 Richard Taylor, Esq., M. Faraday. 



Ed. Phil. Mag., Src. Sfc. 



LXV. On the Motions -presented by Flame when wider the 

 Electro-Magnetic Influence. By Prof. Zantedeschi. 



THE most eminent philosophers have at all times maintained 

 the universality of the magnetism of bodies* ; and in 

 our days Faraday is the only one who has placed the expansi- 



* Raccolta Fisico-Chimica Italiana, t. iii. Dei corpi magnetici e dia- 

 magnetici. 



