and water, 5: 30: 
American Journal of Science for March, 185v, have given 
82 i. Wurtz on a supposed New Minéral.: 
‘ina stoppered bottle, which was kept, during the Sperntiol in © 
boiling water. The ratio of the loss sustained by the tai to 
the #e present, is that. of per agen, 
e I. Oxygen 
Si 30°86 “ 30-98 16°05 16:05 
Al 3:92 ies? 1:83 
Fe 20:25 20-17 6-06 789 
Fe 21:97 ae 4°88 f a 
x 5°30 
Na 1°62 42 
6a G 12°77 any 
sf 8°94 Ser 795 1-95 
100°33 
The ratio for the oxygen of the protoxyds, perasyons silica 
789: 16°05: 7-95=1: 1-49 : 3-03: 1:50 or quite _ 
1h. This gives the general formula 
R2 Si+# Si+3H 
closely 1: 14:3 
or the special formula, 
(1.) (Feé$t + Na gy)? Si+ (Aldg 4 Pe P9)Si+ 3H. 
An attempt to bring the first two analyses under this formula — 
gave the following result. -If we suppose that a portion of the 
iron, whose oxygen, when in the form of ¥e, is equal to one-half 
of the oxygen of the Al present, was actually sk ig in the form 
of #e, the following numbers present themselve 
bas Mean. a 
Si : f 2751 14-29 14:29 
: 10-23 4°78 } 
ai 
Fe 7-97 2°39 
Fe 20°60 458 ) 
9 
Na 1-23 32 § = 
H 8°71 TI4 144 
Cad 22°90 
99°15 
The ratio 4:90: 7:17: 14-29: 
nearly 1: 14:3: 13, as before. 
Thus, upon this hypothesis, the general formula R2 Si+ #Si+3H 
represents these analyses also very well. The special formula for 
this variety wou 
(2.) (Fet$+Na7'5)2 Si+ (A13-+¥e 4) Si+ 3H (or 347). 
The composition is near that of groppite, for which Rammels- 
berg writes the formula R2 Si+#Si+2H. But groppite is a rose- 
red species, containing little iron and lime and much magnesia 
with potash, and moreover Svanberg’s formula for it is very dif- 
ferent. There is sufficient reason therefore, for believing the spe- 
cies here described as distinct, and I therefore propose for it the 
name Melanolite. 
As the recent investigations of Mr. J. D. Dana, published in the 
increased 
7'74=1: 1-46 : 2-92: 1:58 of 
Pi bs 
Z, 
