Terreslrial Magndisin. 101 



proved by the miasmata, which sometimes impregnate the at- 



mosphercj and yet baffle the skill of the chemist to detect them, 



although the disease which follows in their train establishes their 



existence. 



If we examine what are termed the magnetic fluids on the 



poles of the loadstone, it appears that we can neither see, feel, nor 

 taste them, they are not easily disengaged from the particles of 

 the iron, and the only proof of their existence is the attraction 

 they exert. • May not this difficulty in perceiving them, arise 

 from their atoms being so exceedingly small, as to be apprecia- 

 ble only to a higher order of senses than we are endowed with. 



1 



sensations are un- 



Light and heat will pass through transparent bodies without mucl 

 difficulty, but Mr. Haldat has shown that the magnetic fluids will 

 not only pass through transparent substances, but through all 

 bodies, even the most dense ; — and from this I argue, that they 

 are of greater tenuity than either light, heat, or electricity. 



The sun is continually emitting rays which reach the earth in 

 immense quantities, and the question has been significantly 

 asked, but not so easily answered, if they are material bodies, 

 what becomes of this flood of light and heat ? They do not ac- 

 cumulate on the earth's surface like snow, but disappear as fast as 

 they arrive. It may be said they become latent. This supposes 

 that light and heat, as usually understood, are perceptions of the 

 mind, and that the exciting causes of these 

 known principles or substances, as evanescent and difficult to ap- 

 prehend as the magnetic fluids themselves. Now, may it not be, 

 that these substances hitherto incognita, are the identical ele- 

 ments or fluids, whose attraction causes the phenomena of mag- 

 netism, and that instead of light and heat being mere sensations, 

 excited by we know not what, they are real material bodies, com- 

 pounded of these and other elements. 



I here suppose, that there are three elements ; one of which is 

 common to light and also to heat ; that light and heat are each 

 composed of two simple elements; and that when the sun's rays 

 reach the earth, they are decomposed by the attraction of the 

 bodies on its surface, with which their elements unite, and from 

 which they can be again extricated by different processes. 



We know that light and heat can be obtained from almost 

 every fomi of matter, and the idea here offered to explain their 

 disappeai-ance and reappearance, by a decomposition into simpler 



