FIG. 5.
FIG. 6.
7. Put one or two ounces of the solid substance into a dol, or bucket, which has been filled with water drawn from the well about to be treated. Stir it up, and pour the red solution thus produced into the well, leaving the portion of permanganate that is not yet dissolved at the bottom of the dol. Lower the dol into the well, fill it with water, draw it up, pour back the water as before, and repeat the process till all the permanganate has been dissolved. In all cases enough permanganate should be added to produce a faint red colour lasting for 24 hours.
8. If the water in the well is bad, more permanganate will be necessary. In such a case it will be found that the strong red colour at first produced quickly changes to brown, and then fades away. This is because the permanganate destroys dirt and is destroyed by it. Therefore, if the water in the well is clean, a smaller quantity of permanganate will be necessary. From one to four ounces of permanganate will be found to be enough for ordinary wells. If more permanganate is added than is enough to produce a faint permanent red colour, it is likely that frogs, that may be in the well, will be killed. This will, in a few days, give the water a putrid taste. If the quantity of permanganate is not enough to produce a faint permanent red colour, it is unlikely to do good. If possible, the permanganate should be added at night, in order to leave the wells undisturbed as long as possible. The water will be fit to drink on the following morning. If then a red colour is still present, the water may have an unpleasant taste, but it is perfectly harmless.
Figure 4 is an illustration of the latest pattern of well adopted.
New Wells.
When a new well is proposed, and local conditions are suitable, a safe form is that designed by Dr. Cameron of Wigton, N. B. This arrangement is shown in Fig. [5]. The well should be in the centre of a reserved area of at least 20 yards in diameter, and the lead pipe leading from it to the pump must be fitted by brass screw joinings. This is a suitable design for the vicinity of cutcherries, where an open space for a reserved area is generally available.
Another excellent design for a new well, and one more generally suitable, is shown in Fig. [6]. This prevents any danger of the water being contaminated by dirty vessels being lowered into it for the purpose of drawing water.