344 COLORADO METEORIC IRONS. 



the opinion, then first expressed, that copper would be found 

 in all meteoric irons ; this has been the result of examinations 

 of many well-known meteoric irons and all new ones that have 

 come under my examination. 



One or two grains of the iron is all that is necessary for the 

 examination, if it be done carefully; but four or five grains had 

 better be used. Dissolve the iron in chlorhydric acid, and if 

 necessary add a little nitric acid ; it is as well at all times to 

 add a drop or two at the end of the operation. Evaporate 

 away the excess of acid, add water, precipitate with sulphur - 

 eted hydrogen until there be an excess of gas in the solution ; 

 throw on a filter and wash with water containing a little US, 

 dry the filter, burn in a porcelain crucible, treat the residue 

 in a little nitro -muriatic acid, and evaporate to dryness, with 

 the addition of a drop or two of sulphuric acid; treat the 

 residue with water, when the introduction of a clean plate 

 of iron will cause a deposition of the copper with all its 

 characteristic properties. 



2. Bear Creek Iron. 



Of this there are two short notices in the November number 

 of the Amer. Jour, of Science and Arts, pages 260 and 286. 

 The specimen of it in my possession has enabled me to make a 

 thorough examination of the constituents. The piece I have 

 has a portion of the exterior attached. 



As has already been stated by Prof. Shepard, it is coarsely 



crystalline, and laminated from the effects of decomposition 



between the crystals; the surface contains considerable pyrites, 



although Prof. Shepard did not discover any in his specimen. 



I was enabled to separate and analyze magnetic pyrites, 



schreibersite, and nickeliferous iron. Of the magnetic pyrites 



sufficient was separated to make a quantitative determination, 



which was as follows : 



Sulphur 35.08 



Iron 61.82 



Nickel 41 



Insoluble residue 1-81 



99.12 



The schreibersite was not obtained in sufficient quantity for 

 a complete analysis ; about fifty milligrammes of the pure min- 



