Putrid Water should always be purified by boiling it together with charcoal or charred sticks, as low fevers and dysenteries too often are the consequences of drinking it.  The mere addition of charcoal largely disinfects it.  Bitter herbs, if steeped in putrid water, or even rubbed well about the cup, are said to render it less unwholesome.  The Indians plunge hot iron into putrid water.

Thirst, to relieve.—­Thirst is a fever of the palate, which may be somewhat relieved by other means than drinking fluids.

By exciting Saliva.—­The mouth is kept moist, and thirst is mitigated, by exciting the saliva to flow.  This can be done by chewing something, as a leaf; or by keeping in the mouth a bullet, or a smooth, non-absorbent stone, such as a quartz pebble.

By Fat or Butter.—­In Australia, Africa, and N. America, it is a frequent custom to carry a small quantity of fat or butter, and to eat a spoonful at a time, when the thirst is severe.  These act on the irritated membranes of the mouth and throat, just as cold cream upon chapped hands.

By Salt Water.—­People may live long without drinking, if they have means of keeping their skin constantly wet with water, even though it be salt or otherwise undrinkable.  A traveller may tie a handkerchief wetted with salt water round his neck.  See p. 223.

By checking Evaporation.—­The Arabs keep their mouths covered with a cloth, in order to prevent the sense of thirst caused by the lips being parched.

By Diet.—­Drink well before starting, and make a habit of drinking only at long intervals, and then, plenty at a time.

On giving Water to Persons nearly dead from Thirst.—­Give a little at a time, let them take it in spoonfuls; for the large draughts that their disordered instincts suggest, disarrange the weakened stomach:  they do serious harm, and no corresponding good.  Keep the whole body wet.

Small Water Vessels.—­General Remarks on Carrying Water.—­People drink excessively in hot dry climates, as the evaporation from the skin is enormous, and must be counterbalanced.  Under these circumstances the daily ration of a European is at least two quarts.  To make an exploring expedition in such countries efficient, there should be means of carrying at least one gallon of water for each white man; and in unknown lands this quantity should be carried on from every watering-place, so long as means can possibly be obtained for carrying it, and should be served out thus:—­two quarts on the first day, in addition to whatever private store the men may have chosen to carry for themselves; a quart and a half during the second day; and half a quart on the morning of the third, which will carry them through that day without distress.  Besides water-vessels sufficient for carrying what I have mentioned, there ought to be others for the purpose of leaving water buried in the ground, as a store for the return of a reconnoitring expedition; also each man should be furnished with a small water-vessel of some kind or other for his own use, and should be made to take care of it.