REPORTS FROM THE SECTIONS. 253 
WEDNESDAY, 19 JUNE, 1878. 
Lapsed from want of a quorum. 
WEDNESDAY, 17 JULY, 1878. 
Dr. Lerstvs in the Chair. 
_ The Cuarrman laid on the table a letter from Mr. Gipps, M.E., 
mviting the members of the Section to visit Mount Prospect and 
spect the geological formation of the district. 
_ My. Dixon exhibited a specimen of rich silver ore submitted to 
for examination by the Department of Mines. The sample 
contained sulphides and metal, 10:1 %, and yielded, silver 
522 ozs. 2 dwt. per ton, and gold, 18 ozs. 6 dwt. 10 gr. per ton 
The sulphides consisted of iron pyrites with antimony, and traces 
of copper and lead. Also an ore from the border of Queensland, 
containing 77% copper, 19% lead, and 16 oz. 16 dwt. silver 
e 
i ‘ 
Mr. M‘Curcueon read details of ammonia determinations made 
intervals of Sydney water as supplied to the Mint. He 
ound ;— 
Free ammonia. Albumenoid ammonia. 
Parts per million. P 
1877.—September 7 : ae OO14" a 
10 Se .. 0-016 ais 0°15 
October 5 oo ves) SOTO vee 
25 ie .. 0010 Fis 0713 
30 ve 4. ODIO a 0°18 
November 2 cS .. 0-014 eae 019 
1878.—February 16... ... Trace sh i 
April 23. S a 0-18 
These results show that the Sydney water is about on a par with 
the filtered Thames water supplied in London by the Southwark 
and Vauxhall Companies. 
* 
WEDNESDAY, 21 AUGUST, 1378. 
‘Dr. Lersrus in the Chair. 
‘The Cuarrman reported that he and several members of the 
Section had visited Mount Prospect on the invitation of Mr. 
Gipps, and laid on the table specimens of diorite, éc., which had 
__Mr. Bensusay exhibited a specimen of silicate of copper 
(Chrysocolla) accompanied by native copper and red oxide, from 
‘ 
