228 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



In the next (July, 1895) number of the Journal a further account of the examination was 

 given by Wright, 3 as follows: 



This meteorite fell, on the date above mentioned, in Iowa County, in the State of Iowa. By the agency of Prof. 

 N. R. Leonard, of the Iowa State University, a large amount of the meteoric mass was collected, and from him, by 

 the courtesy of President Thacher of the same institution, a number of fragments were received by the writer for an 

 examination, of which a brief notice was published in the preceding number of this journal. A description of the 

 meteorite, and of the circumstances which attended its fall, by Professor Leonard, will be given in the next number 

 of the journal. 



The meteorite is of the stony kind, not greatly differing in its general appearance from others of the same class. 

 Numerous small grains of metallic iron and of the magnetic sulphide of iron, or troilite, are scattered through the mass, 

 the iron grains ranging in size from the finest particles, like mere powder, to those of the size of a fig seed, with 

 occasionally one as large as a grape seed. 



Among the fragments received there are some which show distinct evidences of a sort of lamination or imperfect 

 stratification, the portions at which the surfaces separated being smoothed down, as if by pressure or friction. Sev- 

 eral minute veins are visible, which appear to be filled with material of somewhat different constitution. Their rela- 

 tion to the general mass can not be distinctly made out, and it is doubtful whether they indicate anything more than 

 that cracks formed in the mass while cooling, and that the fissures thus formed were filled up again, perhaps by the 

 still fluid matter from the interior. They seem to indicate that the mass of which the meteorite probably once formed 

 a part was of great size. 



The recent investigations of Professors Newton, Schiaparelli, Oppolzer, and others, in respect to some of the great 

 meteoric streams, have resulted, on the one hand, in establishing the identity of their orbits with those of certain well- 

 known comets, and on the other, in showing that the bodies belonging to these streams are probably of the same nature 

 as the sporadic or occasional meteorites. It seemed probable, therefore, that an examination of the gases yielded by 

 a freshly fallen meteorite would be likely to furnish important information respecting the tails of comets, and these 

 anticipations were found to be not unwarranted by the results. 



The examination was made in the manner described in a previous article, and with the same apparatus. The 

 first trial, which was made with a qiiantity of iron extracted from the meteoric mass, showed that the gaseous contents 

 differed in a marked degree from those obtained from iron meteorites hitherto examined, inasmuch as they contained 

 a very large percentage of carbon dioxide, with a smaller proportion of carbonic oxide, and a large residue of hydrogen, 

 the two oxides of carbon making about one-half of the gaseous mixture. The percentages obtained in the preliminary 

 trial were: C0 2 , 35; CO, 14; or 49 per cent of carbon compounds, the hydrogen not having been estimated. This 

 was merely a rude approximation, and the amount of CO is overestimated, at the expense of the C0 2 . These results 

 were obtained with the particles of iron separated from the powdered stone with a magnet. The residue, however, 

 contained a considerable amount of iron particles too small to enable them to lift the bits of the stony matrix in which 

 they were inclosed. As this was found to introduce irregularities in the determinations, the portions of meteorite 

 employed in the experiments to be described were finely pulverized in a diamond mortar, and the whole immediately 

 placed in the glass tube to be attached to the Sprengel pump, the iron not being separated from the rest. Larger vol- 

 umes of the gases were extracted than in the first trial, and the relative proportions of the different constituents care- 

 fully determined by analysis. 



Powder formed from about 4 cc. of the solid meteorite was placed in the tube upon the pump, and the air very 

 thoroughly exhausted. It was soon found that the relative amounts of the different constituents driven off by heating 

 the tube varied with the temperature, and the experiments were so conducted that the portions separated at different 

 temperatures could be examined separately. 



On applying the heat of the hand to the tube for a short time, a small amount of gas was liberated, too small for 

 anything more than a rude qualitative test as to its composition, which showed the presence of carbon dioxide and some 

 hydrogen. The tube and its contents were then brought to the temperature of boiling water by surrounding it with 

 a wider glass tube, through which steam was passed for several hours. Gas was given off in considerable quantity, 

 and enough was collected for an analysis. This was found to contain 95.46 per cent of carbon dioxide and 4.54 per 

 cent of hydrogen, the carbonic oxide, if present, being in too small amount for estimation with certainty. A moderate 

 heat was now applied for a short time with a small Bunsen flame, raising the temperature to 200° or 250°. This sepa- 

 rated a still greater quantity of the gases, in the following proportions: C0 2 , 92.32; CO, 1.82; H, 5.86. A stronger 

 heat was then applied for nearly an hour, the temperature, however, being kept below that of redness. About 3 cc. 

 of gas were given off, which was found to consist of C0 2 , 42.27; CO, 5.11; H, 48.06; N, 4.56. The tube with its con- 

 tents was now brought to a low red heat, which was maintained for half an hour or so, the effect being to liberate nearly 

 the same volume of gas as before, containing C0 2 , 35.82; CO, 0.49; H, 58.51; N, 5.18. Finally, it was brought to a 

 full red heat, which caused the evolution of much more gas, yielding, on analysis: C0 2 , 5.56; CO, 0.00; H, 87.53; N, 

 6.91. The whole amount of gas given off was about two and one-half times the volume of the solid portion of the 

 meteorite employed, but this was not the whole, for the heat was discontinued before its evolution had entirely ceased. 

 If referred to the iron alone, it would be about twenty times its volume. 



