140 
Transactions Texas Academy of Science. 
Hidden, William Earl, 
andi Mackintosh, J. B. 
analysis. 
Oxygen Ratio. 
Cbs O 5 
42.79 
79.95 
U O 3 
3.12 
3.24 
u 0 , 
3.93 
2.90 > 
Th O 2 
0.83 
0.62 j 
A.lg O 3 
0.85 
2.49( 
Fe^ O 3 
3.75 Atomic weight, 
7.03/ 
> 51.08 
Yg O 3 etc 
31.36 = 121.77 
32.281 
Pb 0 
1.94 
0.87 
Ca 0 
2.74 
4.89^ 
Ignition Hg O 
7.57 
42.05 
t 44.69 
110“ C. Hg 0 
0.62 
F 
Less 0 — F 
0.502 Atomic ratio, 2.64 
100.002 
0.206 
99.796 
j 
Allanite. Molylbdenite. Molybdite. Cyrtolite. Fluorite. Gumniite. 
Tengerite ( ?) ; Fetid Gas. 
194. Hidden, William Eael. 
On Mackintoshite, a new thorium and uranium mineral, with 
analyses hy W. F. Hillebrand. 
Amer. Jour, of Science, III, A^ol. XLA^I, pp. 98-103. Hew 
Haven, Aug., 1893. 
‘‘History. — iTt is three years since on alteration product ot the new species 
here described was announced, jointly, by the late James B. Mackintosh 
and the writer, under the name of ‘thoro-gummite.’ In the interim a most 
diligent search has been made at the locality in Llano county, Texas, to 
discower the minei-al in quantity, and also, if possible, the parent mineral 
from w’'hich it was derived. In an endeavor to find some fragments of the 
unaltered mineral, I broke up nearly a kilogram of the thoro-gummite, 
with the result of finding less than one gram of a- black mineral, iwhich, 
from the position it occupied loithin the thoro-gummite, we concluded must 
represent the original species. I note here that some irregular cores, of a 
dark-brown translucent mineral, were also found, but they proved to be 
very soluble and not essentially different from the enclosing thoro-gummite. 
They had a density of 4:50- 
“Some chemical tests, then made by the writer, proved the black mineral 
to be practically unaffected by hydrochloric or sulphuric acids, and the 
density as then determined was 5.361. Upon fusing a portion with sodium 
bisulphate a solution (Was pbtained, and it was thus found to be a silicate 
containing about 23 per cent, of uranium oxide ('calculated as UO 2 ), about 
46 per cent, of thoria and a small per cent, of the ‘rare earths.’ 
“No further data were then obtained from the scant material in hand, 
but its relation to thoro-gummite- was made evident. It was among fresh 
shipments of the various thoria and yttria minerals, made direct from the 
locality (Llano county, Texas) , that this ..mineral was again found and 
further analytical work made possible. The new material was unexpect- 
edly found deeply embedded in massive cyrtolite and associated with fergu- 
