206 
ME. N. ST ORY-M AS KELYNE ON THE 
and it is far more difficult to obtain pieces in which it is sufficiently definite in character 
to allow of any measurements at all. It seems probable that the augite is in these cases 
blended in minute quantity, by a sort of tesselation, with the enstatite, somewhat as the 
enstatite is seen to be intercalated in narrow bands between layers of the augite already 
described, although the enstatite in the latter case is in much larger relative amount. 
But I have failed to obtain satisfactory proof of the actual presence of the augite from 
the optical characters of the sections of the mineral as seen in the microscope ; though 
these frequently exhibit a structure in a high degree composite in its crystalline cha- 
racters, the principal sections of the different parts of the mineral being in these cases 
disposed at all sorts of angles of mutual inclination. The analysis of these minerals 
yielded the following numbers : — 
Dark grey tabular variety. 
Transparent white variety. 
Percentages. Oxygen ratios. 
Percentages. 
Oxygen ratios. 
Silicic acid . 
57-597 30-718 
58-437 
31-166 
Magnesia 
40-64 16-238 
38-942 
15-564 
L =16-043 
Lime 
• • • 
1-677 
0-479 
Iron oxide . 
1-438 
1-177 
Potash. . . 
0-394 
0-332 
Soda 
0-906 
0-357 
100-975 
100-922 
Semitransparent grey variety. 
I. 
II. 
III. 
Percentages. Oxygen ratios. 
Percentages. Oxygen ratios. 
Percentages. 
Oxygen ratios. 
Silicic acid . 
57-037 
30-419 
57-961 
30-912 
57-754 
30-802 
Magnesia 
40-574 
16-2171 „„„ 
0-655 } 16 ' 
39-026 
1S ' S98 1 16-0 
0-435 J 
38-397 
wot 
0-678 j 
Lime . . . 
2-294 
1-524 
2-376 
Iron oxide . 
0-867 
0-154 
0-423 
Soda . . . 
0-68 
0-657 
Potash . . 
0-569 
0-569 
Lithia . . 
0-016 
100-772 
99-914 
100-192 
The greater part of the soda and part of the potash in these analyses, as in those of 
the augite, is certainly due to an impurity traceable to a minute amount of these bases 
contaminating the hydrochloric acid employed. The iron is present partly as metallic 
iron in a state of minutest subdivision, in small part also without doubt in combination in 
the magnesian silicate. In every case the bases are slightly in excess of the amount requi- 
site for the formula of enstatite. It would seem highly probable, from the comparison 
of these with the known analyses and with such as I shall have to offer of other meteor- 
ites, that where in these bodies the conditions under which the rock was formed were 
such that the silicic acid was in excess of that required by the formula for enstatite, it 
has remained uncombined in the form of a crystallised silica with the specific gravity of 
fused quartz ; but that where the magnesium and other bases were in excess, a basic 
