os 
Want of Identity between Microlite and Pyrochlore. 119 
with oxalate of ammonia, a precipitate which was converted into 
sulphate of lime, equivalent to 0.08 lime. — veal 
site of 
Titanic acid, : 
Oxide of tin, 
iron, . =| 
; cerium, : ; : : ~ 
uranium, 
‘Lime, . ; ‘ ~ : E oS ne 
“100.0 
e/ This rifeierals is therefore identical with that analyzed by Wén= 
LER. ‘The absence of protoxide of manganese and water, and the 
smaller proportion of oxide of iron in thisspecimen, as indicated 
by the blowpipe experiments, will account for the larger propor- 
tion of titanic acid given in the analysis.” 34. 
Then follows a quotation of the analysis of Pyrochlore by Wou- 
LER, with which Mr. Hayes identifies his own results upon the 
Microlite. But when we find, on comparing the two analyses, a 
difference of more than 17 per cent. in the acid, and of one third 
in the principal base, as well as a wide discrepancy in volatile 
matter, and call to nnd that these results are deduced from a 
single trial, and that upon one grain’s weight of the mineral, we 
watt nine that the conclusion of Mr. Hayes cannot be sus- 
ed upon such slender grounds; and inasmuch as Mr. Tes- 
slemsls refers to the analysis for the confirmation of his views, 
is it not possible that Mr. H. in turn, has unconsciously been in- 
debted to the mineralogical ‘evidence for a a RPE: his: confi- 
dence? Scag Be 
“fin order to speak from present. Aeawled gear tat seek 
though I have no reason to doubt the correctness of former results, 
I subjected 2.142 grains of the above mentioned erystal to the 
following examination; premising however, that my inquiry was 
chiefly direudad to the proofs of columbic acid in the mineral, and 
not to a rigid determination of proportions in the different con- 
stituents. 
A. The powdered whan was white, with only a faint tinge of 
yellow. Heated for half an hour to redness, it scarcely changed 
in color; and lost 0.060 in weight, which equals 2.801 per cent. 
Tt was. ‘then intimately mixed with six times its weight of bi- 
pee bot potash, and the mixture maintained in fusion for half 
“Successive: portions of water were boiled upon the — 
