either by the application of the cold douche, or by diving beneath the glass screen which separates the sudatorium from the tepidarium into the marble basin which fills the centre of the latter apartment. This done the bather is rubbed dry, and then indulges for half an hour in the _dolce far niente_, while he reclines on a divan, reads the paper, sips a cup of coffee and smokes a cigarette. As to the value of the Turkish bath we will speak hereafter, and we will content ourselves in this place by warning the bather not to “overdo” it. He should be guided by his sensations, and should not be tempted to go into this room or that room, or submit to this or that process merely because a friend does so with benefit, or without harm. He must remember that constitutions differ, and if the bath is followed by headache, or a feeling of faintness or lassitude or a want of appetite, he should take this as a warning that the treatment has been too heroic. The strongest Turkish bath is that in which the bather spends his time in the hottest room and finishes with the douche (a process which few can stand); the milder bath is that in which the highest temperature submitted to is about 140°, and the dive into the basin is taken in lieu of the douche. Those who take a Turkish bath for the first time should limit themselves to its milder form. _Mineral Baths_ are baths composed of water in which a considerable quantity of mineral matter has been dissolved, either by natural or artificial processes. It must be remembered that ordinary water is very far from pure, and that even rain-water, the purest of all natural waters, contains a considerable number of saline ingredients dissolved in it. Spring-water or river-water is very largely impregnated with matter which it has dissolved. The water of London contains from 18 to 20 grains of chalk in solution in each gallon, besides other ingredients. The chief of all “mineral waters” is sea-water, and it is necessary that we should examine its composition somewhat closely. The specific gravity of sea-water is 1027, and the quantity of salt dissolved in it ranges from 3·5 to 4 per cent., being least in the Black Sea and the Baltic, and most in the Mediterranean. The following is the composition of the water of the English Channel:-- Water 963·8 Chloride of sodium (common salt) 28·0 Chloride of potassium 0·8 Chloride of magnesium 4·0 Sulphate of magnesia (Epsom salt) 2·0 Sulphate of lime 1·4 Bromide of magnesia } Carbonate of lime } Iodines } Traces. Ammonia } Oxide of iron } ------- 1,000·0 -------