and Remarks' cni the Theory q/' Magnetism. 25 



teristics of the laws that govern many of the phenomena exhi- 

 bited by Hght, heat, electricity, galvanism, and magnetism, has 

 led many to conclude that they were only a modification of the 

 same subtle fluid, or that the principal material that occasioned 

 the effects these agents produced, was variously mixed in close 

 affinity with other substances too etherial for us to detect. What 

 I have already detailed seems to favour this conclusion. 



The most prevalent idea that has long existed respecting the 

 theory of magnetism, is, that the magnetic inffuence proceeded 

 from the north pole of the earth, and was originated either from 

 the abundance of magnetic and iron ore, that was likely to be 

 found there, or from some fluid which unceasingly emanated 

 from the north, similar to the aurora borealis. And, latterly, 

 the polarity of the needle has been referred to the magnetism 

 of the whole earth, or to a law of nature, similar in its simplici- 

 ty to gravitation. The north pole * has, however, been consi- 

 dered the most important of the two poles of the magnetic needle, 

 and the north the great seat of magnetic attraction, even by the 

 latest writers. I cannot perceive, however, that the grounds up- 

 on which this hypothesis is framed are conclusive, or that they 

 do not admit of as clear an explanation being given of the chief 

 phenomena of magnetism, by taking an impartial view, in some 

 respects the reverse of that which is generally maintained, at 

 least in so far as regards the notion that the north pole is the 

 chief magazine of magnetic attraction. 



M. Prevost and others, who conceive that the magnetic fluid 

 is composed of two distinct substances, one of which tends to the 

 north, and the other to the south, suggest that the sun is most 

 probably the source of one of these substances ; and I would 

 humbly propose, but with the utmost deference to those who 

 are more able to judge, whether we may not reasonably enter- 

 tain the idea, that the sun is the chief source of magnetism ? 

 If we take into consideration both the facts already alluded to, 

 and also take a combined glance at the facts already generally 

 known, and explain them upon this principle ; it appears much 

 more clear and plausible than we would at first be inclined to 

 apprehend. 



• I use the term North Pole in the same sense as the French writers, 

 for the pole which pomts to the north. 



