Chemical Theory of Electricity and Magnetism. 7 1 



following experiment: if a bar of iron be set upright on the earth in 

 this part of the world, it becomes in a short time magnetical; the 

 lower end possessing northern polarity, or arctic ether, and the 

 higher end in consequence possessing southern polarity or antarctic 

 ether; which may be Avell explained, if we suppose with Mr. Cavallo, 

 that the earth itself is one great magnet, with its southern polarity or 

 antarctic ether at the northern end of its axis; and, in consequence, 

 that it attracts the arctic ether of the iron bar into that end of it which 

 touches the earth, and repels the antarctic ether of the iron bar to the 

 other end of it, exactly the same as when the southern pole of an 

 artificial magnet is brought into contact with one end of a sewing 

 needle. 



3. The magnetic and electric ethers agree in the characters above 

 mentioned, and perhaps in many others, but differ in the following 

 ones. The electric ethers pass readily through metallic, aqueous, and 

 carbonic bodies, but do not permeate vitreous or resinous ones; 

 though on the surfaces of these they are capable of adhering, and of 

 being accumulated by the approach or contact of other bodies; while 

 the magnetic ethers will not permeate any bodies, and are capable of 

 being accumulated only on iron and steel by the approach or contact 

 of natural or artificial magnets, or of the earth; at the same time the 

 attractive and repulsive powers both of the magnetic and electric 

 ethers will act through all bodies, like those of gravitation and heat. 



Secondly, The two electric ethers rush into combination, when 

 they can approach each other, after having been separated and con- 

 densed, and produce a violent explosion emitting the heat and light, 

 which were previously combined with them; whereas the two mag- 

 netic ethers slowly combine, after having been separated and accu- 

 mulated on the opposite ends of a soft iron bar, and without emitting 

 heat and light produce a neutral mixture, which, like the electric com- 

 bination, ceases to be cognizable by our senses or experiments. 



Thirdly, The wondeuful property of the magnetic ethers, when 

 separately accumulated cm the ends of a needle, endeavouring to ap- 

 proach the two opposite poles of the earth; nothing similar to which 

 has been observed in the electric ethers. 



From these strict analogies between electricity and magnetism,. 



