In the above description, we suppose that the body has been suddenly plunged into the water. If, as often happens with weak or timid people, the bather entersthe bath slowly, and if the water be much be low 60°, the sensation of cold is more striking ; a shivering is produced ; and, as the person advances, so as to make the water rise towards the belly and chest, a shuddering and convulsive sobbing take place, sometimes attended with sickness and head ache.
When the cold bath is applied by way of affusion, its affects are generally more sudden and more tran sient, though, by repeated effusions, they may be in creased and prolonged to any required extent. The degree of returning warmth, in this case, will depend on the circumstance of the body's being freely ex posed to the evaporating action of the air, or protect.: ed from it by proper clothing.
The increase of animal heat, which so generally follows the sensation of cold experienced on the sud den application of the cold bath, is to be ascribed to that reaction of the system which enables, it to resist an external impression by which it might be injured. This re-action is in proportion to the intensity of the cause by which it is excited, and to the vigour of the vital powers, of which it constitutes a peculiar effort. It is this re-action of the system which enables the body to derive advantage from the application of the cold bath ; and, where the re-action does not take place, or takes place only in a small degree, the cold bath has been injudiciously or excessively employed.* Hence, where the system has been debilitated by long continued exertion or disease ; where the tempe rature of the body is below the natural standard ; or, where a profuse perspiration has come on, cold bath. log should be avoided.
From what we have now stated, it appears, that the use of the cold bath is attended with three prin cipal effects : a sudden and powerful shock given to the body on the first application ; a sudden abstrac tion of beat from the surface ;' and the re-action of the system to counteract the shock, and to restore the diminished temperature. In its general and pri mary effect, therefore, the cold bath acts as a power ful stimulus to the whole system, and to this effect its advantages as a remedy are chiefly to be ascribed. It has been disputed, whether, from its abstraction of heat, the cold bath can properly be considered as a stimulant ; but this question, like many others in philosophy and physiology, resolves itself into a mere verbal quibble, and it is not necessary that we should here discuss its merits. See Curries Medical Reports,
3d edit. vol. i. p. 73.
It has been very commonly supposed, even by medical men, that immersion in the cold bath, when the body was considerably heated with exercise or other exertion, is a dangerous practice ; and accord ingly it is a general custom with bathers, who find themselves overheated, to wait till they are cool be fore they plunge into the bath. This opinion and this practice have been examined, and ably contro verted, by Dr Currie of Liverpool, who has shewn, both from theory and experience, that the opinion is erroneous, and the practice injudicious. He has proved, that while the body preserves a temperature above the natural standard of 98°,•and the strength is not exhausted, by perspiration and fatigue, the immediate use of the cold bath is not only safe, but salutary ; and he was for some years in the habit of directing his infirm patients, to employ such a degree of exercise, before entering the cold bath, as might produce some increased action of the vascular sys tem, with some increase of animal heat. Sec Me dical Reports, vol. i. p. 111.
From the effects of the cold bath on the healthy body, we may deduce the following conclusions re specting its employment in the cure of disease : The principal 'advantages to be expected from cold bathing; in a medical point of view, are, the reduc tion of excessive heat, and the producing a salutary re-action of the system. In the former way, it will prove beneficial in all those cases where the tempera ture of the body continues steadily above the natural standard : as in ardent fever, the hot stages of inter inittents, the yellow fever of the West Indies ; and in several febrile diseases, as in the early stages of scarlet fever, measles, and small-pox, so long as there is no appearance of eruption. The mode of applica tion, in these cases, will depend on the strength of the patient ; but, in general, allusion is more advi sable, and more efficacious in reducing the morbid temperature, than immersion. Immediately after bathing, unless in those cases where the heat is very considerably above the natural standard, the patient should be placed in bed, and covered lightly with a ' blanket. In cases where the patient is much debili tated, it may be proper to defend the body by flan nel, from the too violent and sudden action of the cold.