1870.] 



Mineral Constituents of Meteorites. 



155 



meteoric minerals were soluble in acid, the augite and enstatite were sub- 

 mitted to this solvent action. Digested for several hours at 100° C. in 

 hydrogen chloride diluted with half its volume of water, and subsequently 

 in potash for some hours to remove the free silica, the augite and each 

 of the three forms of enstatite proved to be acted upon, the results in all 

 cases showing that the acid simply exercises a solvent action on the mineral, 

 without separating it into two or more distinct silicates. 



The subjoined Table gives the results of the experiments. The degree 

 in which the acid dissolved the mineral was due to the more or less com- 

 plete trituration of the material before treatment. In one case, for which 

 the transparent variety was selected, a repetition of the process three times 

 gave results that left no doubt as to the nature of the action of the acid. 



Of the greyish-white variety of enstatite, after treatment for 20 hours 

 with acid and 12 hours with potash, 9'414 per cent, dissolved, an analysis 

 of which is given in column I. 



Of the grey tubular variety of enstatite, after treatment with acid for 

 16 hours and with potash for a similar time, 7*779 per cent, dissolved, 

 that gave on analysis numbers the approximate value of which is found in 

 column II. 



Of the white variety, after the first treatment for 20 hours with acid 

 and subsequently with potash, 1 2*6S per cent, dissolved, the composition 

 of which is given in column III. By a second treatment of the residual 

 enstatite from this experiment, after 2 hours' trituration with acid for 30 

 hours and potash for 12 hours, 67*84 per cent, dissolved; and on sub- 

 jecting the mineral to a third treatment in a similar way, 51*18 per cent, 

 were dissolved in acid and potash. In the last of these experiments the 

 ratio of the silica to the bases, neglecting the small amount of the former 

 dissolved in the acid, is as 58*4 to 42*0, that of an analysis of an enstatite 

 being as 58*4 to 4T6. 



The solubility of the augite was determined by subjecting it to similar 

 treatment with acid during 18 hours, and with potash for a like time, these 

 reagents removing 7*384 per cent, of the mineral. 



Potash 

 Lithia. 



Silicic acid . . . 

 Magnesia . . . 



Lime 



Iron oxide, &c 



5*408 

 2*367 

 1*048 

 0*18/ 

 0*121 



I. 



5-141 



1-353 



027 



0-676 



0*528 



trace 



II. 



m. 



6-724 



4-61 



0*432 



0-5/6 



0504 



trace 



Soda found 



9-131 

 [0*126] 



7*968 

 Ll*217] 



12-846 

 [1-042] 



X. The Iron of the Busti ^Meteorite. 

 A small pepita of the iron contained in the meteorite was analyzed. 



