C.-LSAS GRANDES METEORITE— TASSIN. 



ill iuiua r(\<4iii and pvapomtod to dryness on tho wator hath; concon- 

 t rated hy(h-oehloric' acid was then added and the whole earefully heated 

 until all the ferric oxide was dissolved and again brought to dryness. 

 This operation was repeated until all the nitric acid was expelled. 

 The residue was then dissolved in 15 cubic centimeters of hydrochlo- 

 ric acid, evaporated till the solution was almost sirupy, and then 

 diluted to al)out 100 cubic centimeters with cold water and filtered, 

 using the ''double filter " method of J. Lawrence Smith. ^ This resi- 

 due was examined and found to consist entirely of carbon. The filtrate 

 and washings from the above were collected and made up to 1,000 

 cul)ic- centimeters, and all the determinations were made in the same 

 solution. The analysis gave: 



Iron 95. 1 3 



Nickel 4. 38 



Cobalt 27 



Copper trace. 



Carbon trace. 



Phosphorus 24 



This corresponds to — 



Nickeliferous iron 

 Schreibersite 



)8.65 

 1.35 



100. 00 



It will be observed that the analysis shows no sulphur and that the 

 amount of carbon present was practically negligible. While it is evi- 

 dent that the carbon and sulphur contents would naturally vary, it was 

 thought worth while to determine whether or not the nickel-cobalt con- 

 tents^were a constant or not. Accordingly successive samples, weigh- 

 ing as nearly as possible to 5 grams each, were put in solution and made 

 up to a definite amount and portions containing the equivalent of 1 

 gram of substance taken and the nickel-cobalt contents determined by 

 the acetate method. Each sample was treated as nearly alike as possi- 

 ble and the precipitation being repeated six times with each. It was 

 found that while in certain cases the nickel-cobalt contents did not vary 

 appreciably from the figures given above, in others the variation was 

 considerable, and in one instance the cobalt was wanting entirely. 

 Thus: 



These figures .show a wide variation in composition in different parts 

 of a mass, the character of who.se etch figures is s uch that it would be 



1 Original Researches, p. 312. 



