H. HebnJwUz on the Interaction of Natural Forces 205 



so ricli a source of heat and light, that there is no necessity 

 - whatever to take refuge in the idea of u store of these forces 

 originally existing* When through condensation of the masses 

 their particles came into collision and clung to each other, the 

 vis viva of their motion would be thereby annihilated, and must 

 reappear as heat. Already in old theories it has been calculated 

 that cosmical masses must generate heat by their collision, but 

 it was far from anybody's thought to mahe even a guess at the 

 amount of heat to be generated in this way. At present Ave can 

 give definite numerical values with certainty. 



Let us make this addition to our assumption; that, at the 

 commencement, the density of the nebulous matter was a van- 

 ishing quantity as compared with the present density of the sun 

 and planets; we can then calculate how much work has been 

 performed by the condensation ; we can further calculate how 

 much of this work still exists in the form of mechanical force, 

 as attraction of the planets towards the sun, and as vis viva of 

 their motion, and find, by this, how much of the force has been 



converted into heat 



The result of this calculationf is, that only about the 454th 

 part of the original mechanical force remains as such, and that 

 the remainder, converted into heat, would be sufficient to raise 

 a mass of water equal to the sun and planets taken together, not 

 less than twenty-eight millions of degrees of the Centigrade scale. 

 For the sake of comparison, I will mention that the highest tem- 

 perature which we can produce by the oxy hydrogen blowpipe, 

 ^vhieh is sufficient to fuse and vaporize even platina, and which 

 but few bodies can endure, is estimated at about 2000 C. degrees. 

 Of the action of a temperature of twenty-eight millions of such 

 degrees we can form no notion. If the mass of our entire system 

 were pure coal, by the combustion of the whole of it only the 

 3500th part of the above quantity would be generated. This is 

 also clear, that such a development of heat must have presented 

 tbe greatest obstable to the speedy union of the masses, that the 

 larger part of the heat must have been difl:used by radiation 

 into space, before the masses could form bodies possessing the 

 present density of the sun and planets, and that these bodies 

 Tnust once have been in a state of fiery fluidity. This notion is 

 corroborated by the geological phenomena of our planet; and 

 with regard to the other planetary bodies,^ the flattened form of 

 the sphere, which is the form of equilibrium of a fluid mass, is 

 indicative of a former state of fluidity. If I thus permit an im- 

 mense 'quantity of heat to disappear without compensation from 

 our system, tLe piMuciple of the conservation of force is not 

 thereby invaded. Certainly for our planet it is lost, but not for 



* No necessity for a " Fire-mist."— Ta, 

 f See note at the end. 



