67 



liiglily probable that this law extends from one planet to 

 another, and to every distance from the sun." 



To my mind this explanation of a planet's revolution round 

 the sun requires the knowledge to be conveyed by some better 

 term, without relying on the prestige of a name. From the 

 various results obtained by analysis of the solar spectrum may 

 be found the different forces produced by electro-magnetism, 

 so abundantly provided for in the immense magnitude of, and 

 power derived from, the sun. 



Of late years a much closer relationship between the sun 

 and the earth than was formerly supposed, has been proved 

 by means of the Spectroscope ; and we may consider that there 

 is a still closer analogy between our own and other planets, so 

 that as electric currents exist on the surface of the earth, 

 similar currents exist on the surface of the other planets and 

 of the sun. Venus, when in a crescent form, often appears 

 to be covered with a phosphorescent light in the dark part, 

 which indicates the presence of Auroras at the poles of that 

 planet. 



The sun is known to have a mean density equal to that of 

 water, but not everywhere homogeneous or uniformly dis- 

 tributed. The radiation, therefore, to which the sun is sub- 

 jected must greatly disturb the distribution of caloric, and 

 develope a large amount of electricity, which is a perennial 

 source of heat and light. " This heating force," says Professor 

 Donatti, " which the sun produces through infinite space, 

 when it comes to be confined in the bowels of the earth, is 

 changed into that force ^which the magnet obeys; in this 

 ma,nner all motions are produced, whence arises heat, then 

 electricity, magnetism, and light, which when combined form 

 universal attraction, and eventually gravitation." 



In solar chemistry, it is concluded with certainty, that in 

 the sun's atmosphere, at a distance from us of 91,328,600 

 miles, the burning heat is produced by substances, the follow- 

 ing of which have been found, viz., — calcium, barium, mag- 

 nesium, iron, chromium, nickel, copper, zinc, strontium, cad- 

 mium, cobalt, manganese, aluminium, titanium, and hydrogen. 

 The lines of all these substances have their dark representa- 

 tives in the sunlight, and are so characteristic and distinct 

 as to leave no doubt of their presence. Many metals still 

 remain undiscovered in the spectrum of the sun. There is 

 exhibited in London a chromo-lithograph, which contains five 

 hundred of Fraunhofer's dark solar lines, which, in all pro- 

 bability, have a representative in both the stellar and solar 

 spectrum. In the former, especially in southern climes, where 

 the atmosphere is clear, the stars are not all white ; here and 

 there may be seen, in beauteous contrast, richly coloured 



