302 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



visiting St. Louis soon after, I was informed by Professor Swallow, the state geologist, that a specimen had also been 

 transmitted to him by letter from the same place; and that Professor Litton had found it to be composed of similar 

 constituents. Professor Swallow presented me a small fragment of his specimen, upon which I am able to offer a few 

 remarks, awaiting the results of Professor Litton 'a analysis, for fuller information. 



The mass evidently belongs to the rather rare group of amygdaloidal meteoric irons in which, like those of Stein- 

 bach (Saxony) and Hainholz (Westphalia), the peridotic ingredient preponderates over the nickeliferous iron. Its 

 specific gravity is 4.46. The iron is remarkable for its whiteness, while the peridote is of a well-marked green color, 

 and distinctly crystalline. No pyrites is visible in the very small fragments examined. It is reported that two con- 

 siderable masses of this meteorite were found buried in the soil of a hillside ; and that they are at present secreted under 

 the belief that they contain silver. 



In 1865 mention was made in the American Journal of Science of the receipt by J. Law- 

 rence Smith 3 of a piece of the meteorite as follows : 



Prof. J. Lawrence Smith has received a portion of a new meteorite from Arkansas, consisting of mixed iron and 

 stony matter, which he has under investigation. 



Under the title of the "Newton County, Arkansas," meteorite Smith 4 gave a detailed 

 description as follows: 



The first notice of the meteorite of Newton County was made in 1860 by Professor Cox, who was engaged in the 

 geological survey of Arkansas. Tlhe original has not been obtained; the only fragment of it being in the hands of Judge 

 Green, was given to Professor Cox, who has kindly presented it to me. The weight of the fragment is 22.5 ounces, 

 and was evidently broken off from one corner of the mass, as it presents three of the original surfaces. 



This meteorite is of the mixed variety, and can not be classed with either the metallic or stony meteorites; it is 

 one of the most interesting that has been discovered in the United States, differing from any other that has yet been 

 found in these regions. 



The stony matter is very distinctly crystallized, and some of the minerals can be easily detached and examined 

 separately. The metallic portion constitutes somewhat over one-half of the mass, and owing to the diffusion of the 

 stony matter has a coarsely reticulated structure. 



When broken under the hammer, and the iron separated by the magnet, it is obtained in coarse grains varying 

 from 3 to 4 grains down to very small fragments. The exterior is of a rusty color, roughened by projection of nickel- 

 iferous iron, and over several parts of the surface there is a white incrustation. 



Specific gravity taken on different species varies from 4.5 to 6.1. By mechanical means and the aid of a magnet, 

 the following minerals were separated: 



Nickeliferous iron. Hornblende. 



Chrome iron. Olivine. 



Sulphuret of iron. Carbonate of lime. 



Nickeliferous iron. I may as well mention the manner in which I separate the iron from the stony matter of 

 meteorites. In most instances it is necessary to sacrifice a fair portion of the specimen. The mass is crushed in a 

 eteel mortar. The magnet is then able to take out the iron from the mass of stony matter, especially if the crushing 

 operation is repeated two or three times. The iron is then introduced into an iron or, better still, a silver capsule or 

 crucible, and a strong solution of potash added. Heat is applied until all the water is driven off, and the residue is 

 heated to redness. On cooling water is applied, and the excess of potash washed out, as well as some silicate of potash 

 that is formed. After thoroughly washing the particles of iron they are moistened with a little alcohol, and dried on 

 blotting paper with a gentle heat; and by holding a magnet a little distance from them the particles of iron will adhere 

 to the magnet, almost perfectly free from earthly matter. 



The iron, if of a coarse reticulated structure, as the one in question, may require to be crushed in the steel mortar 

 after treatment by potash, to detach particles of silicate remaining in small crevices; and in this variety I sometimes 

 repeat the treatment by potash. In this way the foreign matter associated with the iron can be reduced to one half 

 per cent. Of course this process sacrifices more or less of the iron, especially if the iron be in very small particles. 

 But this sacrifice is of secondary importance compared with the necessity of having the metallic matter in a pure state. 

 Thus purified the iron was found to be composed of: 



Iron 91. 23 



Nickel 7. 21 



Cobalt 71 



Phosphorus) 100 sma11 to be estimated. 



99.15 



In the analysis, after separating the iron by the acetate of soda, the nickel and cobalt were separated by nitrate 

 of potash; which method I have used frequently and with the best results. Liebig's method of accomplishing the 

 same end has been much improved by the modification lately devised by Professor Gibbs, of dissolving the oxide of 



