The cold affusion, or the suddenly pouring cold water over the whole surface of the body, operates as a powerful remedy, although its effects as such are of short duration. They are produced by the suddenness of the application affecting the nervous energy, and by the shock rousing the dormant sensibility, so as to induce a new action, as it were, of the nervous system, carrying off a large portion of morbid heat by general evaporation, and exciting insensible perspiration; thence restoring the healthy action of the exhalants and the capillaries. In typhus fever this mode of applying cold water has been productive of the best effects.1 It should be resorted to in the first hot stage of the disease, if possible, and repeated every time the morbid heat returns. If the water can be impregnated with salt, so much the better; but when the disease is advanced, its temperature should not be more than 26° 2 under that of the body. It often suddenly arrests the disease, if it be used during the three first days, or so late even as the fifth; but after this period it can be regarded as a useful auxiliary only, even when properly employed. In tetanus, Currie affirms 3 that the cold affusion also proves useful, particularly when the shock is considerable, and applied during the convulsions.

It is, however, in idiopathic tetanus only that it proves beneficial, no advantage being obtained from using it in tetanus arising from wounds.4 Its utility has also been proved in many of the exanthemata : for instance, during the hot stage of the eruptive fever of small-pox; and we can bear ample testimony to its efficacy in scarlatina maligna, when the heat rises to above 100°.5 This remedy, however, is productive of much mischief when misapplied; and therefore it is necessary to observe, that it is contra-indicated in the cold stage of fevers, and when a sense of chilliness is present, although the thermometer indicate the real heat to be more than natural. It may prove injurious, also, when the patient displays much dread of the affusion. It is also said to be improper in fevers, when diarrhoea or dysentery is present; after the sweating stage in intermittents is formed; after the eruption is completely formed in confluent small-pox; and in symptomatic fever occasioned by great local inflammation.

Dr. A. Nicoll found it useful in India, in remittent and intermittent fevers, accompanied with dysentery; when the heat of the surface exceeded 98° Fahrenheit; for as in these cases the dysenteric symptoms seem to depend on the degree of febrile excitement, the cold water, by producing a solution of these, allays the griping and tenesmus, and natural stools follow. The affusion should always, in such cases, be preceded by bleeding and other depletory means.6 The water should be dashed from a moderate height; and its temperature should be nearly that of the air at the time. The cold affusion, in the form of the shower-bath, is advantageously employed as a stimulant and tonic in diseases of general debility. I know of no remedy so generally useful in those affections which are known by the name of nervous complaints.

Warm Water, or of a temperature from 86° to 100°, gives the sensation of warmth to the body, and is applied both locally and generally, in the form of vapour, fomentation, and bath. Water is found in a state of nature combined with different quantities of caloric within the above range of temperature. In the Buxton hot springs the temperature is about 82°; at Bristol it is from 74° to 84°'; and at Bath the range is from 110° to 114°.7 The necessary degree of temperature, however, is generally obtained by artificially heating the water.

The general application of warm water is by means of baths. When the greater part of the entire body is immersed, the water constitutes properly a bath {balneum); but when half only is immersed, it is a half bath (semicupium). The bath may be either, a. The hot bath (balneum calidum), from 97° to 106°.

b. The tepid bath (balneum tepidum), from 86° to 96°.

c. The vapour bath (balneum vaporis), from 109° to 130°.

1 The cold affusion was employed by Antonius Musa, physician to Augustus, when that emperor was affected with a bowel complaint, which had resisted every other remedy. Vide Q. Horatii F. Epistol. ad Num. Valam. C. Sueton. Trang. Oclavius Aug. ii. cap. 81. p. 104. Cold affusions in the fevers of Asia are also prescribed by the Koran, and used in India by the Mahometan and Hindoo physicians in various diseases.

2 Currie, Reports on Cold Water, i. 31. 3 Ibid. i. 138. 4 Ibid. i. 159.

5 Currie gives the following results of the affusion : -The heat of the body in fever, as indicated by the thermometer, being 103°, was by it reduced to 98°, in half an hour; and the pulse from 112 to 80 beats (vol. i. 22.); the heat 101o was reduced to 99°; and the pulse from 112 to 98 in the same time. The heat 106° was reduced to 98°; and the pulse from 130 to 90 (vol. i. 46.).

6 Lond. Med. Repository, vol. ix. p. 123.

7 The temperature of the Cross Bath pump is 110°; the King's Bath 112°; and the Hot Bath 114'.

The two first differ in temperature only; but the last, from the water being applied in a very minutely divided state, acts with much greater effect than water in the liquid form. The operation of the first of these forms of applying water is stimulant; it augments the action of the heart and arteries, renders the skin red, quickens respiration, and produces a copious flow of sweat. It also increases the bulk of the body. But the others, although they excite the sensation of heat, yet lessen the frequency of the pulse, relax powerfully the skin and simple solids, and diminish generally increased excitement.

Warm and vapour baths l are efficaciously employed in acute rheumatism, inflammation of the abdominal viscera, of the kidneys, bladder, and uterus; in suppression of urine, and in spasmodic affections, particularly those to which infants are liable, arising from dentition and other irritations. The general relaxation produced by their use has been taken advantage of, also, for assisting the reduction of strangulated hernia; for, although the effect be not topical as it regards the hernial tumour, yet the general relaxation produced gives a disposition to all the parts to regain their proper place. The tepid bath is found to be very useful in the rigidities which follow some acute diseases, as gout and rheumatism, nodosities of the joints 2, and, according to some, the rigidities attendant on old age.3 Its effects in promoting the natural excretions by the skin render it very serviceable in promoting the cure of herpetic eruptions; in slight cases of lepra the use of it with friction is all that is required; and in all cutaneous foulnesses it is a most important auxiliary. It has also been found very beneficial in cases of insanity.

In general the period of immersion should not be less than twenty minutes, nor exceed one hour. 4

The partial application of warm water as a remedy is made by means of of these can be regarded only as vehicles for retaining the heat and moisture. At all times, flannel cloths wrung out of boiling water are superior; both because the water is applied in the form of vapour, and also, while they continue as long warm, they do not wet the bed and linen of the patient. The flannel cloths should be each about two yards long, with the ends sewed together, so that by means of two sticks, one being at each end, turned in opposite directions, they may be wrung much dryer, when taken out of the boiling water, than could be effected by the hands. The principal circumstance to be attended to in the application of fomentations is the frequent renewal of them, in order that a steady and constant heat may be applied to the fomented part.

1. a. The foot bath (pediluvium); b. The hip bath (coxaeluvium); and c. The hand bath (manuluvium).

2. d. Fomentations of vegetable decoctions; and e. Flannel cloths wrung out of boiling water, by which the moisture is applied in a state of vapour. These partial baths are useful in the same diseases for which the general baths are employed; but are better adapted for relieving the rigidity of single joints and topical inflammation; and the hip bath has lately been found to be very beneficial in suppressed menstruation, and for relieving the pains of cancer in utero. For fomentations it is the practice to employ vegetable decoctions; but the best

1 A very simple and convenient vapour bath for military practice was recommended by my friend, Dr. A. Nicoll. It may be formed of a common beer or spirit barrel, with a false bottom, placed about a foot from the bottom of the cask, and perforated with numerous small holes. A gun barrel connected with the spout of a tea-kettle placed on a fire is to be introduced into an opening in the side of the cask between the real and false bottom; and the patient being seated on the false bottom, the steam or vapour from the boiling kettle soon surrounds him by rising through the holes. It must be prevented from escaping by means of a blanket, which should cover the open end of the cask, and apply closely round the neck of the patient.

A still more simple vapour bath is formed by placing a bucket of boiling water close to a chair on which the patient is seated, and surrounding both the bucket and the patient with a blanket pinned round the throat of the latter. A hot brick thrown into the water renews the extrication of the vapour.

2 Hay garth, Clinical History of Diseases, 8vo. Lond. 1805.

3 Tepid bathing with friction is said by one author, "vitam saepe per plures menses, interdum etiam per aliquot annos, protraxisse." - Gregory, Conspectus Med. ii. 100.

4 The Arabian physicians used the vapour bath in a singular mode, in scrofulous affections, which they denominated Bother : - " ponatur sub puero olla plena aqua calida, in principio apparitionis pustularum, utattrahatab interioribus superfluum humorem ad corporis superficiem."-Rhazes de Morbis Infant, cap. 10. by Willan, p. 31.