Ccxx 
then again fit for use. If the filter contain charcoal which can be taken 
out, this may be first boiled in water containing a little permanganate of 
potash, and then baked inan oven. Unless cleansing be regularly carried 
out, the organic matter accumulated on the filter may render the water 
of worse quality than it was originally. 
Very hard water containing large quantities of lime and magnesia salts 
may be rendered more fit for drinking by boiling, with the addition of a 
very small quantity of carbonate of soda, it is softened, its medicinal 
effect destroyed, and some of the organic matter also carried down by 
the precipitate formed. Lime water will have a similar effect in cold 
water, if the hardness be due to carbonates, while recent experiments 
show beneficial results in organically impure waters from tke addition, 
to each gallon, of two grains of dissolved alum. It is advisable, how- 
ever, not to rest content with purified water if by any possible means 
an originally pure supply can be obtained. 
RESULTS OF ANALYSES. 
Grains per }{ Parts per 
Gallon. Million. 
as ; a) & 
Source of Supply. =o g zi one 
S = 26/28 
a S »a!]sq 
= re feo = 
3 is} 8 =] 
2 ag 
lo) (2) < i <q 
A <q 
CRESSY. 
1. Creek supplying Cressy] 6°02] 0 42 
Pe DTH Ee as | 5°60] 052]| 012] O18 
3. Marsh draining into 
Creek ... ae --| 672] 0°59 || 0°29) 0°37 
4, ane of house ee ; anh 
ever Case) .. “ 10°50*| 07 0°61 : 
5. Barrel neti Hulled 
So 
et 
i) 
S 
a 
Ko} 
door to No. 4) (70™| 7-70| 0:35) 3:20] 314 
6 Tank ix neigh- cree™: 
bourhood 3 4:06] O77 || 069| 0°27 
7. Lake River bee ..| 700! 168}) 0-21] 0138 
EVANDALD. 
1. South Esk River sal] OS) 1:08 || 0°01] 013 
2. Nile Creek (Gutte- 
ridge’s) .. oe ..| 145 | 0°46}} 010] 013 
3. Ditto (common supply)| 55 | 0°46 || 0°07] 0°09 
4, Well, near graveyard..| 33°0 | 10°80 || 0°08) 0:26 
For comparison :— 
A. Dr. Hassall’s proposed 
Standard for greatest 
allowable impurity ..)1417}) — 0:05} 010 
B. London Water Supply 
(Thames) .. 600 S|] ake 1:2 0-01; 0°06 
C. Thames, London Bridge] — — 1:02] 0°59 
D. Effluent from sewage...} — 9°9 || 16°20} 0-90 
E. Hobart supply, taken 
the day after heavy rain 
had succeeded drought | 7:28] 0°70|| 0°02] 011 
F. Cascade Brewery Re- 
servoir .. 50 --| 3°92] 0°56 || 0:01} 0:09 
G. Ditto, Diamond Drill | 65:03 | 23:82 |/Trace |Trace 
H. Well, near Green 
Ponds .. oo «| 86°80 | 29°00 || — = 
I. Well, near Emu Bay ..| 6:02] 1:02]] 0°40] 0:23 
K. Rain Water (tank near 
drain) ane d0 -.| 3:92] 021 || 012) 016 
L. Cascades Reservoir ...J — — 0°01] Q11 
M. Tapin Laboratory ...} — — |}0°005| 0:07 
*Sediment, in addition to dissolved solids, 51°8 
mineral matter, 11°2 organic matter. : 
Nitrogen as Nitric and Nitrous Acids :—Evandale. 
—1., 0°25; 2., 011; 3., 0°10; 4., 21°41. A.,0:90; B., 
3°50; H., Traces. 
