H. S. Washington — Jerome Meteorite. 451 



great difficulty, on account of the very dense and compact tex- 

 ture, and after two days had been spent in successive separa- 

 tions under alcohol, and after analyses of the products had been 

 partially completed, this method was abandoned. 



Eggertz'-s iodine method* was finally employed and proved 

 fairly satisfactory. It seems, however, very desirable that some 

 method be devised for the determination of the separate 

 amounts of Fe, Ni, Co, FeO, Fe 2 3 , NiO and CoO, which does 

 not involve the use of either iodine solution or solutions of such 

 salts as double mercury or copper, ammonium chlorides, whose 

 employment involves considerable extra outlay of time and 

 labor, and whose action on certain constituents of meteorites is 

 not well known. f From a penological, and indeed from a chem- 

 ical and mineralogical, point of view, meteorites are analogous to 

 terrestrial igneous rocks, and should be treated as such. In the 

 analysis of terrestrial rocks the separation into soluble and in- 

 soluble portions has been long abandoned, except for certain 

 special investigations, since the separations are never either con- 

 stant or complete, and since they are generally unnecessary, 

 .because the microscope and methods of chemical calculation 

 enable us to determine the mineral constitutents and their 

 relative amounts with great precision. 



It is evident, however, that a complete analysis of a stony 

 meteorite by the ordinary methods of such analysis is not suffi- 

 cient, since the metallic Fe, ~Ni and Co would be necessarily 

 confounded with the oxides in the usual analytical processes, 

 and their amounts — an important feature — would not be known, 

 except roughly through the excess of oxygen. 



A line of work which has suggested itself seems promising. 

 This would consist in determining the total iron as Fe 2 3 , Fe 

 and FeO as FeO, by the usual methods ; determining the in- 

 crease in weight by ignition in a current of oxygen, and the 

 decrease in weight by ignition in a current of hydrogen, J both 

 before and after ignition in oxygen. From these oxygen data 

 and the amounts of Ni and Co as determined in the usual 

 course, the separate amounts of the various metals and oxides 

 of the iron group could, it would seem, be determined. Our 

 knowledge of the action of oxygen and hydrogen upon the 

 various silicates that go to make up meteorites is as yet far too 

 small for employing such a method at present, and many ex- 

 periments both as to the character and constancy of the action 



* Blair's Iron Analysis, 3d ed., p. 79. My thanks are due to Prof. H. L. Wells 

 for the reference to and description of this process. 



f Cf. Cohen, Meteoritenkunde I, 1894, 13. 



\ Reduction in hydrogen has been proposed by Baumhauer and Rammelsberg, cf . 

 ' Cohen, op. cit., p. 12. Baumhauer reports that at sufficiently low temperatures sili- 

 cates and troilite are not acted on by hydrogen. For this suggestion I am par- 

 tially indebted to Prof. Pirsson, with whom I discussed the matter 



