METEORITES OF NORTH AMERICA. 135 



stone, and hence, if we follow Brezina, would be placed in the group of intermediate chondrites brecciated (Cib). 

 As, however, I have examined this stone only in thin sections, none of which includes an area of above 10 mm. square, 

 it is possible that further study might relegate it to the Cgb group, of which the Pultusk stone is a well-known 

 representative." 



The chemical analysis was found to be somewhat troublesome, particularly in regard to the distribution of the 

 iron present in several different chemical conditions. The greater part of the metallic nickel-iron, accompanied by 

 some schreibersite and pyrrhotite, was separated from a pulverized sample of about 50 grams, free from crust, by 

 means of a magnet, but is was not possible to obtain complete separation in this way, so that a small proportion of 

 silicates had to be deducted from the magnetically separated part, and a small proportion of the constituents of the 

 nickel-iron, schreibersite, and pyrrhotite to be in like manner deducted from the siliceous part of the mass dissolved 

 by acid. The part left by the magnet was digested with hydrochloric acid of 15 per cent strength for three days at a . 

 moderate heat, and thus a general separation of the decomposable silicates was effected, but several determinations 

 of particular constituents had to be made on individual portions. Hydrofluoric acid was used to obtain the alkalies, 

 and the same reagent, with exclusion of air, to secure a determination of ferrous iron. 



The following statement gives the general result reached: 



Enstatite 44. 73 



Olivine 33. 48 



Maskelynite (?) 6. 87 



Nickel-iron 8. 63 



Iron rust ". 3. 03 



Schreibersite 76 



Pyrrhotite 2. 14 



Chromite 08 



99. 72 

 BIBLIOGRAPHY. 



1. 1906: Mallet. A stony meteorite from Coon Butte, Arizona. Amer. Journ. Sci., 4th ser., vol. 21, pp. 347-355. 



COOPERTOWN. 



Robertson County, Tennessee. 



Latitude 35° 30' N., longitude 87° 2' W. 



Iron. Medium octahedrite (Om) of Brezina; Caillite (type 18) of Meunier. 



Known since 1860; described 1861. 



Weight, 17kgs. (37 lbs.). 



This meteorite was first described by Smith 1 as follows : 

 This mass of meteoric iron came into my possessidn during the month of December, 1860, being sent by Professor 

 Lindsley, of Nashville, Tennessee. It was discovered by Mr. D. Crockett near Coopertown, in Robertson County, 

 Tennessee. The time of its fall is not known. Its weight was 37 pounds. Its form was wedge-shaped; and its extreme 

 dimensions were: Length, 10 inches, breadth, 9.5 inches, and thickness, 5.5 inches. Its specific gravity is 7.85. On 

 cutting through the mass a nodule of sulphuret of iron was discovered about one-fourth of an inch in diameter, and 

 there are doubtless others in its interior. The iron, on analysis, furnished: 



Fe Ni Co Cu P 



89.59 9.12 0.35 trace 0.04 =99.10 



Brezina 2 in 1885 classes Coopertown in the Toluca group, and states that, corresponding to 

 the greater breadth of its lamellae (1.2 mm.), it shows a more swollen appearance. 



Huntington 3 gives an illustration of an etched plate and describes a specimen which he 

 regards as showing octahedral, dodecahedral, and cubic plates. 



Meunier 4 describes the structure as follows: 



This iron yields larger figures than ordinary caillite without, however, taking on the character of bendegite. The 

 kamacite bands are frequently 2 mm. thick. The taenite is relatively scarce. The plessite is very pure. There is no 

 pyrrhotine visible; however, dissolving in acid disengages hydrogen sulphide. 



The meteorite is distributed, the Harvard collection possessing the largest quantity, 2,065 

 grams. 



BIBLIOGRAPHY. 



1. 1861: Smith. Description of three new meteorites. — Robertson County (Tennessee), Meteoric Iron. Amer. Journ. 



Sci., 2d ser., vol. 31, p. 266 (analysis). 



2. 1885: Brezina. Wiener Sammlung, pp. 210, 211, and 233. 



3. 1886: Huntington. Crystalline structure. Amer. Journ. Sci., 3d ser., vol. 32, pp. 294 and 295. (Illustration of 



etched plate.) 



4. 1893: Meunier. Revision des fers m^teoriques, pp. 52 and 56, 57. 



