118 Want of Identity between Microlite and Pyrochlore. 
: wailing ; and according to the rules of forming the species in 
~ mineralogy, Microlite must still stand distinct fron Pyrochlore. 
‘Let us now turn toa review of the analysis of Mr. Hayes. 
This gentleman has not in any form, alluded to a paper of miné, 
entitled “Chemical Examination of Microlite,’ and published 
in Vol. xxxu, p. 338, of this Journal. To save the reader the 
trouble of referring to that article, I will simply quote from it so 
far as to say, that I found the Microlite to be a columbate of 
lime and yttria, with moisture and traces of uranium and tung- 
stic acid. ‘The details of the examination were fully given in 
that communication ; and in particular, the proofs that the mine- 
ral was a columbate. My surprise was therefore not inconsidera- 
ble, to find the subject of my former labors held up in a light so 
novel, as — of being a sai ofa vues new and non-isomorphic 
genus. 
- The paper of Mr. oe in support of page views, is out of pro- 
portion full on points, where the evidence is unsatisfactory ; and 
silent, where the reader might appreciate its value as affecting the 
point at issue: for I hold the blowpipe characters of complex 
bodies like the Microlite to be simply sufficient for furnishing the 
chemist to tolerable guesses, in aid of subsequent and more cer- 
tain experiments with chemical reagents, upon the decomposed 
and separated ingredients of the mineral. After nearly a page of 
blowpipe results, many, if not all, of which would be likely, in 
other hands (with different lamps, blowpipes, and lungs, as well 
as different sized specimens and proportions of fluxes), to be af- 
forded from specimens of half a dozen other species as well as 
from Microlite, we have the steps of the analysis given in the 
following words. “One grain of the mineral which had been 
dried was decomposed ; the titanic acid carefully separated and 
dried, it weighed 80; this had the chemical characters of pure 
titanic acid. 
_ “The solution of the oxides from the titanic. aad gave a pre- 
epitate of sulphate of tin, when treated with sulphohydric acid, 
and the sulphate* oxidized before the blowpipe gave with soda a 
globule. of tin. Sulphohydrate of ammonia gave a black pre- 
cipitate, which when roasted contained oxides of iron and ura- 
nium, with traces of oxide of cerium. The fluid remaining gave 
* The a] The sphar finer referred to, by Mr. Haves, in this as well as in 
the previous 
es 
