26 ANNIVERSARY ADDRESS. 
being added to, it cannot improve, unless it were possible to with- 
draw large quantities of the water, and supply its place with rain- 
water ; but during by far the greater number of years during 
which the lake has been known, viz., sixty-four years, the supply 
of rain-water going into it annually has not been equal to the 
evaporation, and there is no other outlet. After the great flood 
of 1870 the lake, during the last fourteen years, has gradually 
decreased by nearly a foot per annum, and similar conditions 
existed before ; and it is therefore obvious that it would not be 
possible to wash out the salts with rain-water and artificial 
drainage except in wet years—perhaps once in twenty years. 
Extract Mining Department’s report, 1880 :—“ Three samples. 
of water from the Currawang Copper Mines were sent for analysis, 
with special reference to their poisonous action on the fish in 
Lake George, and were therefore only examined with regard to 
the metals in solution. The metals were present as sulphates, 
and are stated below :—Water from the creek contains : Sulphate 
of copper, 1:12 grains per gallon ; sulphate of zinc, 16°78 grains 
per gallon ; sulphate of iron, 0:43 grains per gallon, Water from 
the working shaft: Sulphate of copper, 17°67 grains per gallon ; 
sulphate of zinc, 53-54 grains per gallon; sulphate of iron, 1°42 
grains per gallon. Water from the old shaft: Sulphate of copper, 
6°42 grains per gallon ; sulphate of zinc, 7°20 grains per gallon ; 
sulphate of iron, 0°98 grains per gallon.” This water would 
necessarily be poisonous to fish, and flowing into a lake without 
outlet, would ultimately render the whole water poisonous. 
Technical College Laboratory, Sydney, 2 May, 1885. 
My dear Mr. Russell, 
The water raed Lake G contains 187°5 grains per gallon of solid 
sae at 212° F, The re veh — . wey ee alkaline reaction, effer- 
acid, blackens sina on ignition, but does not show the presence 
of n yeen in doing so. e me s present _ aluminium, calcein = 
the renege of magnesia. It should be bornein mind, however, that 
g tter frequently have a purgative 
P.S.—Zine sind copper are entirely absent. 
