356 Description of the Meteoric Stone of Concord. 



We have then 



Silica 3 atoms, . . . 80*959 

 Magnesia 1 atom, . . . 12*076 



Tersilicate of magnesia, 

 Silica 1 atom, 

 Sodal " . 



Silicate of magnesia, 

 Per cent. 





93-03J 



4014 





2-718 







6 732 



99-767 



Or stating the analysis in the usual form we have 



Silica, 

 Magne 

 Soda, 



84-973 

 12-076 



2-218 



99-767 

 Loss and hygrometric moisture, . 0*233 





100-000 



This gives as the formula, Mg Si 3 -J-Na Si, which is unlike 

 that of any known mineral of terrestrial origin, but which ap- 

 proaches the composition assigned by Prof. C. U. Shepard to a 

 mineral first observed by him in the meteoric stone from Bishop- 

 ville m South Carolina, and which he states,* "is a tersilicate of 

 magnesia." For this mineral Prof. Shepard has proposed the 

 name of Chladnite. It is believed that the mineral now under 

 consideration is identical with that in the Bishopville stone, and 

 should therefore be called by the same name. The analysis 

 above given was commenced by myself, but being called away 

 from home before its completion, I entrusted it to my friend arid 

 pupil, Mr. B. W. Bull of Hartford, to carry through, which he 

 did in a very satisfactory manner. , 



In conclusion I would say that the chemical constitution oi 

 the body under consideration, in connection with the very satis- 

 factory testimony of Mr. Noyes as to its falling from the atmo- 

 sphere, as already described in the introduction to this article, 

 leaves no doubt in the mind of the writer, that it is a meteorite. 



Yale College Laboratory, July 24 1847. 



This Journal, ii Ser., vol. i, p. 381 



