288 MEMOIR ON METEORITES. 



Yet another point of resemblance to certain of our terrestrial 

 igneous rocks is the presence of metallic iron, for lately Mr. 

 Andrews has proved the existence of metallic iron in basaltic 

 rocks; but this will not be insisted on, as the quantity of iron 

 discovered in basaltic rocks is so minute as only to be detected 

 by the most delicate means of investigation. 



Ever since the labors of Howard in 1802 the chemical con- 

 stitution of meteorites has attracted much attention, more 

 especially the elements associated in the metallic portion ; and 

 although we find no new elements, still their association, so far 

 as yet known, is peculiar to this class of bodies. Thus nickel 

 is a constant associate of iron in meteorites (if we except the 

 Oswego, N. Y.. meteorite upon whose claims to meteoric origin 

 there yet remains some doubt); and although cobalt and copper 

 are mentioned only as occasional associates, in my examination 

 of near thirty known meteorites (in more than one half of 

 which these constituents were not mentioned) I have found 

 both of the last-mentioned metals as constantly as the nickel. 

 With our more recent method of separating cobalt from nickel 

 very accurate and precise results can be obtained as relates 

 to the cobalt. The copper exists always in so minute pro- 

 portion that the most careful manipulation is required to 

 separate it. 



Another element frequently but not always mentioned as 

 associated with the iron is phosphorous. Here again my test- 

 ing of thirty specimens led me to a similar generalization 

 concerning phosphorus ; namely, that no meteoric iron is to 

 be expected without it. My examination has extended as well 

 to the metallic particles separated from the stony meteorites 

 as to the meteoric irons proper. It may be even further stated 

 that in most instances the phosphorus was traceable directly 

 to the mineral schreibersite. 



These four elements then — iron, nickel, cobalt, and phos- 

 phorus — I consider remarkably constant ingredients. First in 

 the meteoric irons proper, and secondly in the metallic particles 

 of the stony meteorites; there being only some three or four 

 meteorites among hundreds that are known in which they are 

 not recognized. 



As regards the combination of these elements it is worthy 

 of remark that no one of them is associated with oxygen, 



