314 Royal Society : — 



total Tolume of gas obtained from the iron, it becomes necessary to 

 reduce this volume to the same standards of pressure and tempera- 

 ture employed by him. In the paper read before the Royal Society, 

 as reported in its ' Proceedings/ I find no statement in regard to such 

 standards; but, supposing it probable that the barometer at 30 

 inches and thermometer at 60^ F, were referred to. I hare calculated 

 the volume of gas obtained in all from 1 5 "8 7 cub. centims. of iron as 

 equivalent under these conditions of pressure and temperature to 

 50"40 cub. centims., or 3*17 times the volume of the metal. This 

 is a somewhat larger quantity than that of Graham, namely 2'85 

 times the volume of the Lenarto iron used ; but the time of heatmg 

 was longer in the experiment now described, and the temperature 

 attained probably much higher. 



As to the nature and relative amount of the constituent gases, the 

 results differ very noticeably from those of Graham, as is evident 

 when the figures of the two analyses are placed side by side : — 



Lenarto iron, ^^^^^^^^^o., 

 \ irginia iron. 



Hvdrogen 85-68 3o-83 



Ga'rbouic oxide 4-46 38'33 



Carbonic anhvdride 9'7o 



Nitrogen..." 9-86 16-09 



lOO'OO 100-00 



The gases obtained in the experiment now in question agree more 

 nearly with those of common wrought iron (clean horseshoe-nails) 

 as foimd by Graham*, viz. in the first portion collected, — 



Hydrogen 35-0 



Carbonic oxide 50-3 



Carbonic anhydride 7"7 



Xitro2:en 7"0 



100-0 

 and the conclusion arrived at by him, that '' the predominance of 

 carbonic oxide in its occluded gases appears to attest the telluric 

 origin of iron," would deny to the Yirginia specimen the right to 

 be classed amongst meteoric masses, with which, however, all its 

 other physical and chemical characteristics agree most fully. 



It is to be noted that the analysis of the gases from the Lenarto 

 iron was not made with the whole of the gaseous matter collected : 

 the first portion, amounting to about 32-5 per cent, of all collected, 

 was used for merely qualitative examination ; the second portion, 

 57' 6 per cent., was that fully analyzed; while no mention is made 

 •of the disposition of the remaining third portion of 9-9 per cent.; 

 and it is stated that the iron was not fully exhausted at the end of 

 two hours and thirty-five minutes, for which time only the experi- 

 ment was continued. In my own experiment it appears probable 

 that the amount of hydrogen ^and withit the total volume of gas) has 



* Loc. cit. 



