I have said that the temperature of Mr. Witt's bath is 135°, and a very agreeable temperature it is; but the temperature of the bath is a point upon which a few observations must be made. The temperature of the Calidarium in Mr. Urquhart's and Mr. Rolland's bath is 170°, and is equally agreeable, equally fresh, equally enjoyable. What then, it may be asked, is the difference between these baths, that renders such a wide range of temperature equally pleasant? It is one of construction. Mr. Witt's Calidarium is small, well ventilated for its size, but a higher temperature than 135° or 140° would be oppressive if more than two or three bathers were present. Moreover, in Mr. Witt's bath, there is an invisible vapour of water in suspension in the atmosphere. Mr. Rolland's bath is larger than Mr. Witt's, and the atmosphere perfectly dry. Size of apartment and dryness of atmosphere are therefore the opposites of restricted space and moist atmosphere. Mr. Urquhart's bath, with a higher temperature than Mr. Rolland's, is fresher than either, because he has been enabled to combine greater size, greater altitude, a fresher material, namely, marble, moisture, and partial heating by means of the hypocaust. So the question of temperature must be regarded as relative, and not positive; a higher temperature will be fresher in a large and well-ventilated bath with few inmates, than a lower temperature in a small and less perfectly ventilated apartment. Whereas, the bath that may be fresh and agreeable in the morning when few bathers are present, may be insufferable in the after part of the day when a succession of bathers has rendered the atmosphere moist, or when many bathers are therein. The effect of many bathers being necessarily to curtail space, infuse moisture into the atmosphere, and deteriorate the ventilating medium. The temperature of a bath must therefore be specially adapted to the particular bath; it must rise or fall with its proportions or with its means of ventilation; it must rise or fall with its number of bathers; it must rise in the morning and fall in the evening. We may fix the temperature of a hot bath, but we cannot determine that of a Turkish bath.