402 Mr. E. H. Cook on the Regenerative 



contrary, that in the analysis quoted* there is no less than 

 four times as much carbon dioxide as in ordinary atmospheric 

 air. This particular analysis is moreover somewhat favour- 

 able than otherwise, inasmuch as some meteors contain a much 

 larger quantity of C0 2 . -Thus Dr. A. W. Wright (Amer. 

 Journ. of Sci. ix. p. 459) found as much as 35 per cent., 

 and J. L. Smith (Chemical News, xxxii. p. 221) found 13*03 

 per cent, of this gas. If, therefore, these bodies derive their 

 gaseous constituents from the interplanetary atmosphere, it 

 must be one very rich in the heavy gas carbon dioxide. But 

 I imagine that a very much easier explanation of the presence 

 of hydrogen and the lighter gases can be given. As I am not 

 aware that such an explanation has been given before, it will 

 be necessary to state it rather fully. 



In a very full and complete memoir by F. Mohr (Liebig's 

 Annalen, clxxix. pp. 257-282), in which the author discusses 

 the origin of meteorites, it is proved that they possess a porous 

 structure. By heating in a stream of dry carbonic-acid gas 

 and collecting the water in anhydrous cupric sulphate, it is 

 proved that in the pores of these bodies water is contained. 

 Out of seven meteorites examined an average quantity of 

 water of *856 per cent (*285 to 1*43) was found. Also the 

 author concludes from experiment that organic substances 

 analogous to ozokerite exist in them. Lawrence Smith 

 (Comptes Renclus, lxxxii. pp. 1041 & 1507) has also shown the 

 presence of carbonaceous bodies in meteoric masses. It is also 

 well known how largely iron enters into the composition of 

 these substances. Such bodies come into contact with our 

 atmosphere and are immediately raised to a high temperature — 

 a temperature sufficient to melt their outer surface, and which 

 Mohr (loc.cit.) has been enabled to imitate by exposing them to 

 the oxyhydrogen-flame. The first effect of this heat will be to 

 decompose the organic materials, which will really be subject 

 to a process of destructive distillation, one result of such de- 

 composition being the production of marsh-gas. The carbon 

 will either be set free or will combine with oxygen to form 

 carbonic anhydride or carbonic oxide according to the amount 

 of the latter element present. This oxygen would be obtained 

 in this way : — if an oxide of iron is present, the organic matter 

 would probably reduce some of it to either the ferrous condi- 

 tion or to the metallic state; and it is in these conditions that 

 we find the iron to exist. But the larger portion of the oxygen 

 and the greater part of the hydrogen (some of this would pro- 

 bably be obtained by the decomposition of the organic matter, 

 just as we find it thus produced in coal-gas) would be pro- 



* Dr. Flight's. 



