METEORITES OF NORTH AMERICA. 143 



Smith " made a detailed study of the graphite from one of the Cosby Creek masses as 

 follows: 



In this communication I call special attention to a large nodule taken from the very center of the Sevier iron, the 

 largest that has come under my observation, and perhaps the largest known. It was detached from the iron entire 

 and perfect in every respect. Its greatest length is 60 mm. ; its dimensions in the other direction vary from 20 to 35 

 mm. The weight before it was cut was 92 grams. Its form is that of an irregular dumb-bell, flattened on one side and 

 slightly nodular on the surface. Its color is plumbago-black, except at small places on the surface, where there is a 

 little bronze-colored troilite. Its texture is remarkably close and compact, and it is cut readily by the saw, except 

 when the tool encounters particles of inclosed troilite. Its structure and powder is not unlike that of the close-textured 

 graphite of Borrowdale in Cumberland, England, and quite unlike the scaly graphite such as that from Ceylon or that 

 found in certain cast irons. 



Examined from the circumference to the center this nodule presents the fojlowing appearance: About one-fifth of 

 the circumference of the section is made up of troilite with a thickness of 1 mm. The Ktmainder of the section has all 

 the aspect of graphite except in a few spots. In the nodule there is a small mass of troilite not unlike in form the entire 

 nodule; it is 10 mm. long by about 5 mm. wide; it is not continuous from its circumference to its center, but the center 

 portion is cut off completely from the exterior portion by a thin belt of graphite 0.5 to 0.75 mm. in thickness. Again 

 on other parts of the surface small particles of troilite are to be seen. 



The specific gravity of this graphite is 2.26, as determined on a piece in which no troilite was visible to the eye and 

 after it was immersed in water and placed under the receiver of an air pump to abstract the air from its pores. 



Chemical character of the graphite nodule. When pulverized and heated from 100 to 150 C. in a short glass tube 

 water is given off which is doubtless water absorbed from the air by the graphite. If heated a little higher and then 

 brought close to the nose a slight empyreumatic odor is apparent; if heated still higher there is a slight odor of sul- 

 phureted hydrogen. If heated in the open air the carbon is burnt with difficulty, showing its true graphitic nature. 



Treatment of the graphite by ether. Very pure and concentrated ether was added to 2 grams of material in powder 

 and nibbed up in a porcelain mortar, then poured into a small beaker, a little more ether was added, and the two 

 allowed to remain together for 12 or 18 hours, the vessel being covered to prevent evaporation. The ether was 

 then filtered off from the graphite, which was finally washed with a little ether. The ether was allowed to evaporate 

 slowly in the uncovered beaker, placed where the temperature was about 33 C. After the ether had evaporated, long 

 colorless acicular crystals covered the rides of the vessel, and some shorter ones were in the bottom. There were also 

 some rhomboidal crystals and rounded particles. The solid residue exhaled a peculiar odor of an aromatic character, 

 somewhat alliaceous. The quantity of these crystals was small, not exceeding 15 milligrams from 2 grams of the 

 graphite. Heated on a piece of platinum foil, they fuse at about 120 C. Heated in a small tube .closed at one end, they 

 first melt and then volatilize, condensing in yellow drops that soon solidify leaving a carbonaceous residue. They are 

 not soluble in alcohol, but very soluble in sulphide of carbon. Fuming nitric acid oxidizes the material and gives as one 

 of the products sulphuric acid. The quantity was too small to admit an ultimate analysis, but it was very evident that 

 sulphur was the predominating constituent, the remainder being carbon and hydrogen. These three elements may be 

 combined, forming a peculiar sulp-hydrocarbon which in a previous note I called cehstialite, or it may be sulphur con- 

 taining a minute quantity of hydrocarbon that gives the peculiar odor and determines the somewhat singular form of 

 crystallization of the sulphur, for these acicular crystals may be only elongated rhombohedrons. 



Be the compound what it may, it is a matter of chemical and astronomical interest that a solid graphite nodule 

 thus incased in iron should contain a sulph-hydrocarbon, or free sulphur and a hydrocarbon. 



The graphite powder after treatment with ether was then treated with the bisulphide of carbon (which was redis- 

 tilled just before use), and after standing two or three hours was thrown on a filter; the filtrate was evaporated to dryneas, 

 and the residue was a yellow solid; in this instance, as in the last, the quantity was small. This, when heated in the 

 open air on platinum foil to a red dull heat, first melts at about the temperature that sulphur melts, and finally the 

 sulphur is burnt off, leaving a carbonaceous residue. When heated in a tube it sublimes, leaving a black residue. 



To all appearances this is the same substance, or mixture of substances, that was extracted by the ether, the ethr 

 not having exhausted the graphite in the first treatment. 



Later Smith lt oxidized the graphite of the meteorite. 



In 1878 Smith 13 found daubr6elite in the troilite of the meteorite. 



In 1881 Smith " mentioned thin white metallic spangles from decomposed portions of the 

 meteorite which contained 27 per cent of nickel and 73 per cent of iron. This was undoubtedly 

 tsenite. 



Brezina 1S classed Cosby Creek in the Bendego group of coarse octahedrites. The width of 

 the lamellae he gave as 1.5 to 2 mm. The characters which he assigns to this group are as 

 follows: 



Lamellae bunched, irregularly bounded, strongly hatched, with lively oriented sheen. Kamacite predominant; 

 fields, combs, and plesrite lacking or minute. 



