JUNE, 1911. ANALYSES OF STONE METEORITES — FARRINGTON. 201 
a) In case there is no wollastonite this is done after distributing Si O, tentatively 
to form leucite, nephelite, and olivine, and noting the deficit of Si O. by means of the 
equation: 
ie e of the deficit of Si Ov. 
y = molecules of akermanite. (4 Ca 0.3 Si O:). 
Ca O is to be taken from diopside, and the Mg O and Fe O so liberated are to be cal- 
culated as olivine. 
b) In case an excess of Ca O has been set aside for wollastonite this is first con- 
verted to akermanite by means of the equations: 
y = the deficit of Si Ox. 
y = molecules of akermanite (4 Ca O.3 Si Oz). 
c) If there are not sufficient molecules of wollastonite to satisfy the deficit of 
silica, recalculate the molecules of diopside and wollastonite so as to make olivine, 
diopside, and akermanite by means of the formule: 
2x + 3 +== available Si Ox. - 
x + 4y = molecules of Ca O. 
x+2 = molecules of Mg O + Fe O. 
where x = molecules of new diopside, y = molecules of akermanite (4 Ca 0.3 Si Oz), 
and z = molecules of olivine. 
21. If there is still not enough Si Oz, all the Ca O of the diopside and wollastonite 
must be calculated as akermanite, the (Mg, Fe) O being reckoned as olivine and the 
Kz O distributed between leucite and kaliophilite by the equations: 
x+y = molecules of K. O. 
4x + 2y = available Si Os. 
where x is Kz O in leucite and y = Kz O in kaliophilite. 
22. In case there is insufficient Si O2 and an excess of Aly O3 and (Mg, Fe) O, 
which might form aluminum spinel, an alferric mineral, the excess of Al, O; is to be 
calculated as corundum, and the uncombined (Mg, Fe) O is to be estimated as femic 
minerals, being placed with the nonsilicate, mitic group, magnetite, ilmenite, etc. 
