440 J. L. Smith — Carbon Compounds in Meteorites. 



irons ; for I have proved that they both contain similar crys- 

 talline products soluble in ether and sulphide of carbon, and 

 while the carbonaceous matter reacts differently when treated 

 with nitric acid and potash chlorate, this may arise from the 

 difference of conditions under which the reaction took place 

 that gave rise to it. 



That the carbonaceous matter in the black meteorites is to 

 be regarded as a kind of humus arising from organized matter is 

 contrary to all we know about humus. For if we examine the 

 mineral constituents of these meteorites, we find them to be a 

 granular mass, with particles more or less impalpable, composed 

 essentially of olivine and pyroxene, a most unpromising soil for 

 so luxuriant a growth of vegetation as must have occurred to 

 produce so abundant a percentage of carbonaceous matter as that 

 found in the Orgueil meteorite. The action of caustic potash 

 upon it is different from the action of that alkali upon what is 

 commonly called humus ; (although we must bear in mind that 

 humus is not a well-defined substance; it being commonly 

 regarded as vegetable matter that has not undergone complete 

 decomposition into water and carbon, but by imperfect oxida- 

 tion was converted into a varied mixture of carbon and certain 

 organic compounds rich in carbon, some of them soluble in 

 caustic alkalies). After the powdered Orgueil meteorite has 

 been exhausted by water, ether, and sulphide of carbon, caus- 

 tic potash or soda dissolves but an exceedingly minute trace 

 of the carbonaceous matter, and even that trace may be a little 

 hydrocarbon not extracted from the mass by the ether and 

 sulphide of carbon. If a portion of the same be dried at 110° 

 C, and then heated in a closed tube, water will not be given 

 off until the temperature is elevated considerably. If the tem- 

 perature be further increased, only a very slight odor is appar- 

 ent; and this is another marked difference between it and 

 humus. If heated on platinum foil, the carbonaceous matter 

 burns off very readily with little or no odor, leaving an abun- 

 dant residue. According to my experiments this combustible 

 matter amounts to about 4-5 per cent of the entire meteorite. 



It is not at all improbable that the carbonaceous matter of 

 the black meteorites approaches in character the so-called hy- 

 drated carbon first pointed out by M. Eggert, but so clearly 

 defined by MM. Schutzenberger and Bourgeois in a commu- 

 nication made to the Chemical Society of Paris in April, 1875, 

 which was obtained from white cast iron by dissolving away 

 the iron. But it is a question in my mind whether the carbon 

 combination thus obtained from white iron is to be properly 

 considered a hydrated carbon ; that is to say, whether we are 

 to consider the H^O as united to the carbon in the same way 

 as it is to metallic oxides to form what are known as hydrated 



