WILLIAM SIEMENS, P.R.S. 301 



meteorites; these suv known to travel in loose masses 

 round the sun in orbits intersecting at certain points that of our 

 earth. When in their transit they pass through the denser portion 

 of our atmosphere they become incandescent, and are popularly 

 known as falling stars. In some cases they are really deserving of 

 that name, because they strike down upon our earth, from the 

 surface of which they have been picked up and subjected to 

 searching examination whilst still warm after their exertion. 

 Dr. Flight has only very recently communicated to the Royal 

 Society an analysis of the occluded gases of one of these meteorites 

 as follows : 



C0 2 (Carbonic acid) 



CO (Carbonic oxide) 



H (Hydrogen) 



CH 4 (Marsh gas) , 



N (Nitrogen) 



100-00 



It appears surprising that there was no aqueous vapour, con- 

 sidering there was much hydrogen and oxygen in combination 

 with carbon ; but perhaps the vapour escaped observation, or was 

 expelled to a greater extent than the other gases by external heat 

 when the meteorite passed through our atmosphere. Opinions 

 concur that the gases found occluded in meteorites cannot be 

 supposed to have entered into their composition during the very 

 short period of traversing our denser atmosphere ; but if any 

 doubt should exist on this head, it ought to be set at rest by the 

 fact that the gas principally occluded is hydrogen, which is not 

 contained in our atmosphere in any appreciable quantity. 



Further proof of the fact that stellar space is filled with 

 gaseous matter is furnished by spectrum analysis, and it appears 

 from recent investigation, by Dr. Huggins and others, that the 

 nucleus of a comet contains very much the same gases found 

 occluded in meteorites, including "carbon, hydrogen, nitrogen, 

 and probably oxygen," whilst, according to the views set forth 

 by Dewar and Liveing, it also contains nitrogenous compounds 

 such as cyanogen. 



Adversely to the assumption that interplanetary space is filled 



