Be be 
120 Want of Identity between Microlite and Pyrochlore. 
fused mass for upwards of half an hour, until every thing solu-' 
‘ble was taken into solution. A dense, white powder remained 
undissolved. 
B. Hydrosulphate of ammonia produced, in a portion of the 
solution A, a precipitate, without sensible discoloration, and 
which, from former proofs in my paper of 1835, was taken for 
yttria. The remainder of the fluid was then precipitated by ox- 
alate of ammonia, the precipitate ignited, redissolved in hydro- 
chloric acid, the yttria thrown down by ammonia, and the lime by 
oxalate of ammonia, which on ignition, weighed. { 0.032 or 1.49 
per cent.* 
_C..The white, insoluble matter A, was digested for some time 
in a saturated solution of hydrosulphate of ammonia, the opera- 
tion being conducted on a filter in the way recommended by Brr- 
zeuius. ‘I'he insoluble matter was blackened by the aflusion of 
the hydrosulphate. 
D. The sulphohydric fluid was decomposed by nitric acid and 
heat ; ; hydrochloric acid was added; no precipitation ensued. But 
the fluid, on the addition of ammonia, afforded a precipitate of 
peroxide of tin, which after ignition, weighed .001, which equals 
0.047 percent, ‘The oxide was reduced with carbonate of soda 
on charcoal, to the metallic state. hey 
E. The blackened powder C was sheated with dilate hydro- 
chloric acid, and gently warmed. The filtered solution was pre- 
cipitated by ammonia, and ignited. The peroxide of iron was 
apparently blended with traces of yttria. It weighed 0.022:or 
about | per cent. 
F. The insoluble matter, washed by hydrochloric acid (E) was 
drenched upon the filter, with an abundance of hot water: it show- 
ed no tendency to pass through the filter in a milky state, as titanie 
acid is well known to do, under such circumstances. It was ig- 
nited in a platina crucible, and exhibited a white color while hot, 
as well as after cooling. Its weight after some accidental losses, 
was 1.052 gr.=49.11 percent. But I still regard my former de- 
termination of the proportion of acid, and which was 75,70 ee 
settle to be very near the trath. 
* The Sion soiavas ‘here obtained i is. aiciet uly 35 an approximation ; but 
eee so much: below what I previously found, and considered in “conjunction 
vation of implanted ealcareous spar u nua pane 
- Viv ee ae . 5! - 
