Magnetical Injiuenct of the Sun. 291 



diation, we find that the southern hemisphere is more cooled, and 

 that there remains to the northern (deduction made of the radia- 

 tion) a superiority of heat. This is the result of a train of rea- 

 soning which will be found in the treatise on radiating caloric, 

 sect. 285, to which I can only refer here. 



These truths which I have laboured to establish, in two es- 

 says published in 1792 and 1809? would have been sufficiently 

 confirmed by the experiments of M. de la Roche, and by those 

 of MM. Dulong and Petit, could it be admitted that what takes 

 place in very high temperatures is applicable to lower degrees. 

 But I cannot at present attend to this remark, nor to several 

 others which refer to heat, having another object in view. 



What has been demonstrated of the heat which has emanated 

 from the sun, easily applies to every other emanation from that 

 body. Accordingly, in 1792, I made application of it to a fluid 

 which I was disposed to refer to this origin. Proceeding on 

 the supposition, now very generally received, of two magnetic 

 fluids, I thought that the magnetism of the terrestrial globe 

 might come from the abundance in excess of one of them upon 

 one of our hemispheres. Then, viewing it as probable that such 

 a fluid emanates from the sun, or that in some manner or other 

 the solar emanation affects the magnetism, I proposed to examine 

 if the abundance in excess of this fluid upon our hemisphere 

 might not be attributed to the same cause which produces an 

 excess of heat in it. I remarked, lastly, that, if these supposi- 

 tions were verified, we might hope to detect, between the mag- 

 netic variations and the known motions of the earth's exis, rela- 

 tions that it would be useful to observe. 



These reflections have been suggested to me by experiments 

 which seem to indicate the emission of one of the magnetic ele- 

 ments by the sun, namely, those upon the influence of the violet 

 ray first made by Mr Morechini, and afterwards repeated and 

 varied by Mrs Somexw'AXQ.'-'Bibliotheqiie Universelle, May 

 1826. 



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