which is dependent upon
a fresh-water pond for its water supply, finds that his drinking water
is contaminated, that the taste and odor are such as to render the
water unfit for use. There is no reason why he should not treat the
supply, provided he is properly careful. When the nature of the
polluting organism is definitely determined and the average
temperature of the water observed, then the necessary formula can be
decided upon. First, of course, the pond must be plotted, the depth
found, and the capacity computed. The department will willingly
furnish data for this purpose, together with blanks upon which to
submit details as to contaminating organisms and water temperature,
to any applicant. Once the proper solution is determined upon, the
actual work of purification is most simple. In the following
directions the department outlines the most practicable method of
introducing the copper sulphate into a water supply:

_Directions for the Copper Cure_

"Place the required number of pounds of copper sulphate in a coarse
bag--gunny sack or some equally loose mesh--and, attaching this to the
stern of a row-boat near the surface of the water, row slowly back and
forth over the reservoir, on each trip keeping the boat within ten to
twenty feet of the previous path. In this manner about a hundred
pounds of copper sulphate can be distributed in one hour. By
increasing the number of boats, and, in the case of deep reservoirs,
hanging two or three bags to each boat, the treatment of even a large
reservoir may be accomplished in from four to six hours. It is
necessary, of course, to reduce as much as possible the time required
for applying the copper, so that for immense supplies, with a capacity
of several billion gallons, it would probably be desirable to use a
launch, carrying long projecting spars to which could be attached bags
containing several hundred pounds of copper sulphate.

"The substitution of wire netting for the gunny-sack bag allows a more
rapid solution of the sulphate, and the time required for the
introduction of the salt may thus be considerably reduced. It is best
to select as warm a day for treatment as circumstances will permit."

_Cost of the Treatment_

Not difficult, one would say. No--when the proper solution is
determined; to reach that determination is the difficulty. That the
method can be tried "at home" is proved by the results obtained by the
owner of a country home in the vicinity