PHOSPHATIC MINERALS AND DEPOSITS. 333 
(3.) Marsupial excrement.—This substance had the appearance 
of solid bitumen, and has on several occasions been sent for examin- 
ation. Iam informed that it is usually found in small solid masses 
in caves, or crevices between rocks. A partial analysis yielded as 
follows :— 
Total nitrogen.. , sins «-. 2°24 per cent. 
Equal to potassic nitrate i coy hee,” 9%, 
Phosphoric acid ; a sais i 
Insoluble matter (sand, fe Die hasie wre, CM ODO! «50 
The whole of the nitrogen appears to be combined with potash, 
and the major portion of the phosphoric acid is in a soluble form. 
(4.) Phosphatic deposit from Moruya Caves.—A partial analysis 
yielded as follows :— 
Phosphoric acid (P.O,) .. 27°80 per cent. 
Equal to tricalcic phosphate (Ca,P,0 ) 60-70, 
Calcium carbonate (CaCo,) ... aa PE ss 
Insoluble matter (sand, &e.) ... eo, Gere, 43 
Nitrogen, equal to ammonia ... Sat Oa tes 
(5.) Phosphatic deposit from Moruya Caves.—A partial analysis 
yielded :— 
Phosphoric acid (P,O;) .« 29°83 per cenit. 
Equal to tricaleic ae (Ca,P,0 i ai 6 Le 
Calcium carbonate (CaCo;) ... rape NORIO a ag 
Insoluble matter (sand, &c.) ... a BI. ss 
Nitrogen, equal to ammonia ... #8 453, 
(6.) Fine gem-sand from the Tooloom Alluvial Gold-fields :— 
Cerium oxide ... : ; ... 6:20 per cent. 
Thorium oxide gas Se ea, (a 
Lanthanum oxide = ae dus : 
Didymium oxide — ae oe SON ops 
Phosphoric acid ae wie) - Salhi 0 ee 
(7.) Coarse gem-sand from the mMectaew Alluvial Gold-fields :— 
Cerium earths as oxides ae «+ 1°96: per'cemtt 
Phosphoric acid ar iia sizing LO pet 
Both these samples consist largely of small zircons. A small 
quantity of chrome iron-ore is also present, and a few dwt. of gold 
per ton. 
No. 8._-ON MODERN METHODS OF TEACHING 
CHEMISTRY. 
By W. J. Ciunies Ross, B.Sc. 
(Read Monday, January 10, 1898.) 
