138 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



I. Tea grains were treated with nitrohydrocliloric acid. The metal was rapidly taken into solution; but a blackish 

 residuum remained. This was treated by itself with heated nitrohydrochloric acid for several hours. The quantity 

 was thereby reduced; but a few black grains (of the siz,e of fine-grained gunpowder), together with numerous shining 

 scales, still remained in the fluid. These were well washed and dried. They weighed 0.01 gr. The acid solutions 

 were mingled and precipitated by ammonia in large excess. The fluid stood along with the precipitate for six hours 

 at a temperature of nearly 100°. The peroxide of iron was then separated and thoroughly washed for several hours 

 with tepid water. The washings and the original ammoniated liquor were mingled and boiled; after which they 

 were transferred to a glass bottle and decomposed while hot by potassa. The clear liquid was separated, after twenty- 

 four hours, by filtering (the hydrosulphate of ammonia, when added to it. produced no change in color). The precipi- 

 tated oxide of nickel was ignited and weighed 0.6 gr. The peroxide of iron after ignition weighed 13.4 gr. We 

 have then — 



Iron 93. SO 



Nickel 4. 66 



Undissolved 0. 10 



98.56 

 A second and parallel analysis was conducted upon 30 grs., the results of which were as follows: 



Peroxide of iron 40. 30=Iron 28. 210=94. 033 



Protoxide of nickel 1.68=Nickel 1.333= 4.444 



Undissolved 0. 03=Undissolved 0.030= 0.100 



98. 577 

 The undissolved matter from both the analyses was examined by the microscope. It was principally in soft black 

 grains, along with which were a few brilliant scales of graphite. Both the grains and the scales were attracted by the 

 magnet. On grinding them in a mortar, they gave a brown powder, in which little particles of metallic iron were felt 

 beneath the pestle. The powder was then treated with nitrohydrochloric acid, whereby the iron was dissolved out, 

 leaving behind a fine, blackish brown powder. 



II. Fifty grains of the meteoric iron were now subjected to the following analysis. Distilled water was boiled 

 upon the iron for a few minutes. A portion of the fluid, separated from the iron, gave with nitrate of silver no pre- 

 cipitate; another portion gave with chloride of barium a slight precipitate. The iron was then treated with nitro- 

 hydrochloric acid. The action of the acid ceased after a few hours, numerous flakes of the iron remaining in the flask, 

 as if insoluble. On the application of heat, however, the action was renewed. More acid was subsequently added 

 and the digestion continued, until the solution was apparently at an end. The black grains and shining scales were 

 separated, washed, dried, and rubbed in a mortar as above. The blackish-brown powder (having metallic iron inter- 

 mixed) was treated with hydrochloric acid; a brisk effervescence from the evolution of hydrogen immediately ensued. 

 When the action had ceased, the fluid was decanted, and the residuary, blackish-brown powder transferred to a small 

 platinum capsule, in which it was ignited for a few moments with exposure'to the air, in order to burn off the free 

 carbon. It was then ignited to low redness with twice its weight of nitrate of potassa. Water was boiled on the fused 

 mass; a portion of the blackish powder still remained. The solution was colorless, showing the absence of chromium. 

 Nitrate of silver produced in it a pale, yellowish precipitate of phosphate of silver. The residuary brown powder 

 was now ignited for several minutes with dry carbonate of potassa; water was boiled upon the same; the solution was 

 decomposed by nitric acid, and then evaporated to dryness, after which the addition of water brought flocks of silicic 

 acid into view. The resultB of this analysis gave — 



Iron 93. 80 



Nickel 4. 66 



Carbon 1 



Silicon .... [along with grains of iron and nickel alloy 0. 10 



PhosphorusJ 



Oxygen, sulphate of iron, sulphur, moisture, and loss 1. 44 



100.00 

 Since my return to New Haven, I have paid some attention to another specimen of meteoric iron from the same 

 mass with the above, which was kindly afforded me by Dr. Troost. On breaking it to obtain a fresh fracture, the 

 regular crystalline structure showed itself on the largest scale. The clean surfaces were intersected by layers of bril- 

 liant magnetic iron pyrites, varying in thickness from one-sixteenth to one-fourth of an inch, whereby a series of 

 trihedral and rhombohedral areas of various sizes were produced. These regularly inclosed spaces were mostly black, 

 from the diffusion of a sooty form of carbon between the plates of the meteoric iron. The contrast between the areas 

 and the separating layers of pyrites was consequently rendered more striking. Besides the distribution of the pyrites 

 in plates or veins, it also occurs in balls and almond-shaped masses, sometimes half an inch or more in thickness. The 

 structure of these is concentrically laminar, the laminse being often separated by iron and carbon. The pyrites form 

 nearly one-sixth of the mass. Dr. Troost presented me also with several loose balls of the shape of the pyrites masses, 

 which to the eye seem composed of little else than carbon, concerning which a few remarks will presently be subjoined. 

 None of these balls are found embedded in the specimen I am more particularly describing. 



