PHOSPHATIC DEPOSITS IN THE JENOLAN CAVES. 329 
There is no evidence of bat guano or bone breccia in any part 
of this cave. 
Analysis. . 
Moisture and combined water 39°60 
Silica (Si0.) ‘70 
Alumina (A1,0,) 26°83 
Ferric oxide (Fe,O;) “72. 
Lime (CaO) 8:10 
Magnesia (MgO) 14 
Potash (K,O) 09 
Soda (Na,O) he absent 
Phosphoric acid (P.O;) 30°04 
Carbonic acid (CO.) “15 
Chlorine (Cl) 
.. minute trace 
100°37 
No fluorine or sulphur trioxide present. 
II. 
9°83 
50-10 
13°88 
8:65 
1:02 
14 
I-35 
trace. 
15°38 
100°47 
(3.) The deposit was found on the floor of the Grotto Cave, and 
is protected with a hard surface, covered with small gnarled 
excrescences, found to be gypsum. 
Mr. Harpur, who examined 
this deposit, informs me “that it would appear as if it resulted 
from the alteration of the limestone from below, and is not con- 
nected in any way with the drift or marls.” 
There are similar deposits of this material in the Bone Cave, 
Lucas Cave, and in the Wool-shed Imperial. No indications of bat 
guano or bone breccia were observed. 
Two samples of this material, very similar in appearance 
yielded on analyses as follows :— 
Analysis. 1. 
Moisture and combined water ... 16°82 
Silica (Si0,) ae ~~ oe 37°82 
Lime (CaO) are ote sie 22-66 
Magnesia (MgO) se ae "32 
Alumina (A1,O;) ee ats 64 
Ferric oxide (Fe,0;) _... ... minute trace 
Potash (K,O) ... see Sa inh 
Sulphur trioxide (SO,) ... oe 5:39 
Carbonic acid (CO,) __... susks 24 
Phosphoric acid (P.O;) ... ae L5H 
99:71 
absent. 
trace. 
28:67 
10 
14:50 
100°35 
No fluorine detected. A minute trace of chlorine present. 
