262 A. W. Wright — Gases contained in Meteorites. 



but that from the Pultusk seemed to contain little or none. 

 The latter however, as well as the Parnallee, showed the pres- 

 ence of a minute quantity of sulphurous oxide, the Weston 



A question naturally suggests itself as to the manner of the 

 occurrence of the carbon di-oxide in conditions which admit of 

 its being separated so much more readily than the other gaseous 

 substances. The most probable supposition seems to be that 

 it is condensed upon the fine particles of iron as well as 

 absorbed within them. That it is produced by the decomposi- 

 tion of some carbonate is not likely to be the case, since the 

 carbonates that could occur in meteorites all require high tem- 

 peratures for the evolution of this gas, and the quantities 

 obtained should increase constantly with an increase of temper- 

 ature, whereas the reverse is true ; and certainly none of them 

 would give up the gas at the temperature of boiling water. 

 Another hypothesis might be that it is absorbed in part from 

 the atmosphere. To test this, a re-examination of the Iowa 

 meteorite was made, the material being heated until it yielded 

 as nearly as possible the same volume of gas as in the experi- 

 ments of the preceding year, a short time after its fall. Had it 

 been constantly gaining carbon di-oxide from the air it should 

 have given the same amount of gas as before at a lower temper- 

 ature. On the contrary it required a more intense heating, and 

 a longer continuance of the process. The percentage of CO2 

 was found to be 32-65. If any difference exists therefore it 

 has lost rather than gained, at least in this interval of nearly a 

 year. It is very probable therefore that no considerable part of 

 the gas is derived from the atmosphere, though this cannot be 

 asserted absolutely, and the question must remain for further 

 investigation. The portions of gas from each of the stony 

 meteorites, except the Pultusk, which was not examined, gave 

 cometary spectra, similar to that from the Iowa specimen. 



On reviewing the results of the investigation there appears 

 no reason for modifying the conclusions arrived at in the 

 former article. The evolution of such volumes of carbon di- 

 oxide may well be taken as a characteristic of the stony nieteo- 

 rites, and its relation to the theory of comets and their trains is 

 certainly of great significance. The further discussion of some 

 of the results of the investigation, and certain interestmg 

 questions suggested by them, are reserved for another corn- 

 Yale College, March 18, 1876. 



