Aqua (U. S. P.)—Water.

Related entries: Aqua Destillata (U. S. P.)—Distilled Water - Aquae Minerales.—Mineral Waters - Aquae Medicatae.—Medicated Waters

FORMULA: H₂O. MOLECULAR WEIGHT: 17.96.
SYNONYM: Hydrogen monoxide.
"Natural water in its purest attainable state"—(U. S. P.).

Source, Description, and History.—"A colorless, limpid liquid, without odor or taste at ordinary temperatures, and remaining odorless while being heated to boiling"—(U. S. P). Water is one of our most extensive pharmaceutical agents. The purest water obtainable is distilled water (see Aqua Destillata), which, when properly prepared in clean glass vessels, is colorless, transparent, scarcely compressible, tasteless, and odorless, with the assumed specific gravity 1, being the standard to which the specific gravities of liquids and solids are referred. It is the only admissible water for pharmacal and chemical tests, as the presence of organic or saline substances in it, may decompose the articles to be dissolved, or impair its solvent power. At a temperature of 0° C (32° F.), or lower, it is converted into ice; boils at 100° C. (212° F.), and is converted into steam. Its crystallization into ice is accompanied with expansion, and the specific gravity of ice is 0.916; the volume of steam is about 1700 times more than that of water, and its specific gravity is 0.622. Water is perfectly neutral, exhibiting neither acid nor basic properties, though capable of combining with acid or basic anhydrides, thus developing acids and bases formerly and still incorrectly called hydrates. It likewise readily combines with many gaseous bodies, giving to them a fluid form. As a general rule, its solvent powers are increased by heat, especially in regard to solid bodies. It should always be kept in well-closed, green glass vessels. Pure water is formed by the combination of 2 volumes of hydrogen with 1 volume of oxygen, thus: H₂+O=H₂O or hydrogen monoxide. Water is never found naturally pure, differing in many respects according to its locality. It is generally distinguished as Soft water, Hard water, and Mineral or Medicinal water. For most ordinary purposes soft waters are preferred to the hard, and may be distinguished by the readiness with which they dissolve soap, notwithstanding they may contain considerable foreign matters. Hard waters, on the contrary, holding in solution salts of calcium or other earths, dissolve soap, but subsequently form insoluble compounds with the latter; these waters are unfit for internal use or household or pharmacal purposes. In this respect water is spoken of as having temporary and permanent hardness. The former takes into account the total amount of calcium and magnesium salts, including those that are precipitated by merely boiling the water (see Tests). Permanent hardness refers to those salts alone that remain in solution after boiling the water. The principle involved in the determination of the hardness of a water (by Clarke's process), is simply that the calcium and magnesium salts are precipitated from the water by means of an alcoholic potassium-soap solution, of known strength, previously standardized by means of a calcium chloride solution of definite strength. When all alkaline earths are thus precipitated from the water, a slight excess of the soap solution, upon shaking the water, will cause a heavy froth which remains permanent for at least 5 minutes. The old English degree of hardness was defined as the number of grains of calcium carbonate in 1 gallon of water; by more modern usage, 1 part of calcium oxide (CaO) (German usage) or calcium carbonate (CaCO₃) (French usage), in 100,000 parts of water, is called 1 degree of hardness. Water is distinguished by its origin as follows:

RAIN WATER (Aqua pluvialis) and SNOW WATER (Aqua nivalis), when collected so as to prevent accidental impurities, are the purest waters to be had naturally. They are generally impregnated with the soluble matters in the atmosphere, which vary in different localities, the most common impurities being carbonic acid gas, carbonate of ammonium, chloride of sodium, organic and suspended mineral substances; during a thunder-storm traces of nitric acid and nitrates are said to be likewise present. In collecting rain water, the first that falls should be rejected; if from the tops of houses, 2 or 3 hours of continuous shower will wash off any objectionable impurities, and the water will run clear and transparent; if from an open space at a distance from dwellings, it may be permitted to fall an hour or so before attempting to collect it. To obtain it as pure as possible, it should be filtered, boiled, and again filtered. No pure water should ever be used that comes in contact with new lead—for the lead becomes oxidized by the oxygen of the water, which oxide is converted into a carbonate by the action of the carbonic acid gas derived from the air, and the water thus containing lead may produce the poisonous effects of the metal upon the system. Hard water attacks lead less readily than soft water.

Snow water is said to be richer in oxygen than other water, and is generally free from the atmospheric gaseous impurities found in rain water; it quenches thirst, while snow, not melted, augments it. The opinion at one time entertained that the use of snow water disposed to goitre is undoubtedly an erroneous one, as the disease not only occurs where snow is never seen, but is unknown in many sections of mountainous countries where the water employed is chiefly that supplied by the melting of the snow which covers the mountains. Rain and snow waters, collected with a degree of care, are applicable to every domestic purpose, as well as to many chemical and pharmacal processes.

SPRING WATER (Aqua fontana) is that which springs from the earth, free from large amounts of carbonic acid, or salts, and not possessing elevated temperatures; it is the general beverage of mankind, and is applicable to all domestic purposes. Its quality varies according to the nature of the soil in its vicinity; those springs arising from trap rocks, sandstones, transition, and primitive rocks, are purest; those from alluvial strata, limestone, and coal formations, are the least pure. All, however, contain variable traces of the salts of calcium, sodium, or magnesium, according to the character of the soil through which they flow.

WELL WATER (Aqua puteana) very much resembles spring water in its qualities, its purity being somewhat governed by the depth at which it is procured, and its daily flow. The Artesian Wells usually supply a very pure water. Nitrates and organic impurities have been found in the well water of cities, as might naturally be expected from the impurities of their soils.

RIVER WATER (Aqua fluvialis), especially when passing through alluvial countries, and near great cities, contains suspended in it more or less earthy and organic impurities of a vegeto-animal origin, which lessen its clearness, but in a short time it becomes purified of these by deposition during its downward course. In countries where the rivers pass chiefly over primitive rocks, the waters are found to be almost perfectly pure. When moderately pure, it is fit for all ordinary purposes, though if it contains much organic matters, it is apt to occasion dysentery, and other affections of the bowels, and then becomes inadmissible in medicine.

MARSH WATER (Aqua ex palude), on account of its stagnation and repletion with putrescent matters, is altogether unfit for domestic or therapeutical use. This water contains among other impurities animalcules, and microscopic vegetation; although these are met with in running and clear waters in which there is considerable vegetable growth. But they are absent in spring and well waters, and most of the river waters supplied for domestic purposes. There is no doubt but that the drinking of water containing shreds or filaments of cryptogamous plants, has occasioned sickness and even death. River and lake water (Aqua ex lacu) should always be filtered or boiled before using as a beverage.

AQUAE MINERALES.—(For Mineral Waters see Aquae Minerales).

Impurities in Common Water, and Their Detection.—From 1 to 3 parts in 10,000, or even slightly more of solid matter (U. S. P. permits the limit of 5), if it be composed principally of sodium chloride and calcium carbonate, is permissible in good, wholesome drinking water. It may also contain carbon dioxide in the proportion of 1 volume in 100 volumes of water. The most objectionable impurities are ammonia and organic matter, the presence of which indicate contamination of the water with decaying animal and vegetable tissues. The pharmacopoeial tests for organic matter and limit of ammonia are subsequently mentioned. Water contaminated with sewage or other nitrogenous impurities, contains ammonia, 0.10 Gm. of which in 1,000,000 renders it unfit for drinking purposes. An outline of the quantitative analysis of water, on which subject there are several well-known special works extant (e.g., Wanklyn, Frankland, Miller, etc.), can not be herein considered. The U. S. P. gives the following criteria for the purity of water:

"A colorless, limpid liquid, without odor or taste at ordinary temperatures, and remaining odorless while being heated to boiling. Water should be perfectly neutral to litmus paper, and its transparency should not be affected, nor should any color be imparted to it, by hydrogen sulphide T.S., or ammonium sulphide T.S. (absence of metallic impurities). It should also remain unaffected by mercuric chloride T.S. (limit of ammonia). On evaporating 1000 Cc. of water on a water-bath, it should not leave a residue weighing more than 0.5 Gm. (limit of soluble salts), and this residue, when ignited, should not carbonize, nor evolve ammoniacal or acid vapors. If 200 Cc. of water be acidulated with hydrochloric acid and heated to boiling, and 0.5 Cc. of barium chloride T.S. added, the liquid, cooled and filtered, should give no further precipitate on the addition of a few drops of barium chloride T.S., even on standing (limit of sulphates). If 200 Cc. of water be acidulated with nitric acid, and 0.5 Cc. of decinormal silver nitrate V.S. be added, the filtered liquid should not be affected by the subsequent addition of a few drops of silver nitrate T.S. (limit of chlorides). If 5 Cc. of water mixed with a few drops of diphenylamine T.S. be carefully poured upon about 2 Cc. of sulphuric acid, free from nitrose, contained in a test-tube, so as to form a separate layer, no blue color should be formed at the line of contact of the two liquids (limit of nitrates). If 100 Cc. of water be acidulated with diluted sulphuric acid free from nitrose, and a few drops of zinc-iodide-starch T.S. subsequently added, the liquid should not at once assume a blue or violet color (absence of nitrites). On heating 100 Cc. of water, acidulated with 10 Cc. of diluted sulphuric acid, to boiling, and subsequently adding 0.5 Cc. of decinormal potassium permanganate V.S., the color of the liquid should not be completely destroyed by boiling it for 10 minutes (limit of organic and other oxidizable matters"—(U. S. P.).

Calcium salts in solution are recognized by being precipitated with ammonium oxalate T.S. Free carbonic acid gas in the water may be recognized by the addition of an excess of lime water, whereby insoluble calcium carbonate falls. If lime water is cautiously added in an amount sufficient to combine with only half, or less, of the carbonic acid gas present, the remainder of this gas will keep the calcium carbonate in solution, forming bicarbonate of calcium. This, upon boiling, is decomposed into carbonic acid gas and insoluble calcium carbonate. On this principle calcium carbonate is dissolved by natural water with the aid of carbonic acid gas, and deposited from this solution when its solvent, carbonic acid gas, is expelled by spontaneous evaporation. Organic matter may be recognized, beside the test previously indicated, by evaporating to dryness and igniting, whereby charring takes place to a greater or less degree. Organic matter also will reduce gold from a few drops of chloride of gold solution that have been added to about 1 or 2 ounces of the water to be examined. The reduction of the gold is manifested by a violet or blue coloration of the originally slightly yellow liquid. The presence of ammonia in water, beside the test indicated above, is also detected by Nessler's reagent (see List of Reagents). For the detection of nitrites in water there are several delicate tests. The following test, originally devised by Griess, will detect 1 part of N₂O₃ in a thousand million parts of water. It is carried out as follows: Add to the liquid to be tested some pure sulphuric acid, then a few drops of a solution of sulphanilic acid (C₆H₄NH₂SO₃H) and about 10 minutes afterward a few drops of naphthylamin sulphate (C₁₀H₇NH₂.H₂SO₄). If a nitrite is present, an intense red coloration is developed after a short while, due to the formation of an azo-dye (see Aniline).

Other tomes: Petersen - BPC

Action, Medical History, and Uses.—Lack of space permits of but a brief resumé of the physiological and therapeutical actions of water; for further elucidation the reader is referred to special works on HYDROTHERAPY. The treatment of disease by means of water is by no means modern, as there is ample, evidence of its employment by Hippocrates, and later by Galen, Avicenna, and Celsus. In more modern times its importance in therapy was recognized by Sir John Floyer and Dr. Baynard (England) who employed baths in chronic affections, and particularly by Dr. James Currie, of Liverpool (1797), who published a work upon the uses of cold and warm water in fevers and other diseases. His views, given to the world at a time when even a drink of cold water was rigidly denied the fever patient, naturally met with violent opposition from a large portion of the medical fraternity, though his sensible doctrines and practices met with considerable favor in some quarters. Though affusions were largely recommended by him, an important feature of his practice consisted in the administration of cold drinks in fevers. Later, however, a renewed impetus was given the water treatment through the discoveries of Vincenz Priessnitz, the peasant-farmer of Silesia. Having sprained his wrist, Priessnitz resorted to affusions of cold water, followed by the Umschlag (wet bandage). Priessnitz was but 13 years of age, but so successful was his treatment that in subsequent injuries to himself he resorted to similar treatment. As in each instance, an eruption was produced by the constant wet application, he conceived a theory that it was indicative of impure blood, and this subsequently led him to adopt a "humoral" pathology, and to declare that all morbific matters (acrid humors) were eliminated by "crisis" (the eruption). His treatment was extended to the ulcers, injuries, etc., of his neighbors, and finally, in 1826, he opened an establishment for the treatment of diesease by means of water, and his fame became world-wide. Though lacking in scientific knowledge, and entertaining many mistaken hygienic views, yet his treatment, coupled with improved habits of living and eating, and plenty of fresh air and exercise, proved eminently successful. In 1844 the treatment was introduced into New York City. While undoubtedly much credit is due Currie as the originator of hydropathy as now practiced, its establishment as a therapeutic measure is due to the persistency and the success of the unlettered Priessnitz in pursuing his novel methods of treatment. The treatment, as pursued by Priessnitz and his followers, is that commonly known as Hydropathy; as now employed it is known as Hydrotherapy. Owing to the unscientific and injudicious methods of the followers of Priessnitz, his method gradually fell into disrepute, and in medical circles but little more was heard of it until Brand, of Stettin (1861), gave his scientific reports of the use of cold baths in typhoid fever; since which time the treatment of fevers by means of baths has been by modifications of Brand's method.

In recent years much importance has been attached by some physicians to the cold bath in fevers, particularly those of a typhoid type. According to its advocates, it is contraindicated chiefly by intestinal hemorrhages, which it appears to favor, and by peritonitis. Brand's method is to immerse the patient, wrapped in a sheet and his head first wetted, into a large bath of water at 15.5° to 21.1° C. (60° to 70° F.), whenever the patient's temperature reaches 39° C. (102.5° F.). The body is briskly rubbed through the sheet, and stimulation resorted to if shock and cyanosis seem to demand it. After remaining in the bath for 15 or 20 minutes, the patient is removed from the bath, the wet sheet quickly replaced by a dry one, and the patient placed in bed, covered with a light blanket. The rectal temperature is taken immediately after immersion and again in 45 minutes. When the temperature again reaches 102.5° F. or over, the bath is repeated, and so on indefinitely. Ziemssen's method consists in employing the bath at about 36.6° C. (98° F.), and cooling the water during the immersion, by means of ice, to 26.6° C. (80° F.), 15.5° C. (60° F.), or even 4.4° C. (40° F.), according to effect upon temperature. After the bath, the patient is dried, placed in bed, and covered with blankets. The temperature is taken per rectum. Ziemssen, Immerman, and others, administered the baths at regular intervals; others have modified Ziemssen's method by employing the bath only as the rise of temperature seemed to demand it. Still others, as Osler, have recommended and practiced baths at 29.4° to 32.2° C. (85° to 90° F.) and cooling to 21.1° C. (70° F.). The claims made for the cold bath, and particularly by Brand's method, are: Reduction of temperature, control of muscular twitchings, brightening of the intellect, soothing of the nervous system, the induction of sleep, increased heart-power, improvement of the skin, and low mortality. Ziemssen's method is said to give less shock, and Osler's method is asserted to be less effective in reducing temperature (see also paper by G. S. Harrington, M. D., in N. Y. Med. Times, Aug., 1897, p. 239).

The use of the bath as above described, has not found favor in the Eclectic school. The medical treatment of fevers, as pursued so successfully by our physicians, and with results that have gained fame for the methods of our practice, has been such as to beget an unwillingness to abandon successful and pleasant methods for a procedure at best uncertain, and extremely uncomfortable and annoying to the patient. Briefly, the following resumé will indicate some of the uses of hot and cold water, both internally and externally.

As a remedial agent, apart from its natural necessitous use, water internally is a tonic, diuretic, or sudorific, according to its mode of administration. Small quantities, taken cold, between 7.2° to 15.5° C. (45° to 60° F.), and occasionally repeated, act as a tonic; in larger doses it produces diuresis and diaphoresis, the latter effect more especially, if the patient be kept warmly covered; and it is extensively used for this purpose in many acute diseases. Warm water, of a temperature varying from 18.3° to 37.7° C. (65° to 100° F.), and especially when taken in large quantities, will usually produce sickness and vomiting, and its continued daily use in small quantities will impair the tone of the stomach. Cold water, from 1.1° to 7.2° C. (30° to 45° F.) is a grateful drink, more particularly to fever patients, allaying thirst, moderating the fever, often producing sleep and relief from restlessness, and is sufficient, unaided by other means, to effect a rapid solution of the disease, in many instances. It should never be withheld from patients laboring under febrile or inflammatory complaints, who crave it. During the operation of a vegetable emetic, cool water at 15.5° C. (60° F.), is more agreeable, and fully as beneficial in assisting emesis, as warm. Cold drinks are very useful in chronic constipation, a glass of cold water being drunk before breakfast. With some, warm water acts best as a laxative. Owing to its diuretic effect, an abundance of water assists in washing out the kidneys in acute desquamative nephritis. Water, in judicious amounts, may be administered in acute gastric inflammations. Ice held in the mouth frequently aids in subduing tonsillitis. The ingestion of warm water is frequently useful in gastralgia, dyspepsia, chronic diarrhoea, gout, rheumatism, and in many chronic skin affections.

The effects of water employed externally, depend upon its temperature. The cold bath acts according to its degree of cold, the manner in which it is used, and the peculiar state of the body at the time. When below 10° C. (50° F.), the bath is considered very cold. The primary effects of a cold bath constitute the shock—its secondary effects, the glow, or reaction. The immediate effects of a cold bath are a sensation of cold, which gradually ceases, and is succeeded by numbness, the skin becomes pale, and covered with cutis anserina, there is shivering, with quick and irregular respiration, and a contraction of the cutaneous vessels, as well as of the volume of the body. If the immersion be continued, the pulse becomes slow and small, drowsiness and cramps come on, the heat of the body diminishes rapidly, and finally syncope and death occur. A cold bath is usually taken for its stimulating and tonic influence and hence, should not be below 10° C. (50° F.), nor above 23.8° C. (75° F.), and the immersion should be temporary. Reaction speedily follows, capillary circulation is re-established, a glow is felt, perspiration comes on, the pulse becomes full and frequent, and the whole system feels invigorated. Delicate or weakly persons should not take a cold bath. It is a common opinion that immersion in cold water is dangerous when the body is heated by exercise or other exertion; and hence it is customary with bathers to wait until they become cool. The first is an erroneous opinion; the second an injurious act. Cold water abstracts heat from the body, first becoming sedative, and then, if immersion be not too prolonged, it acts secondarily as a stimulant. Under the cold bath, properly employed, the body gains in weight.

Warm water, according to its temperature, affects the system in varying degrees, but the quality of the action is similar, no matter whether the bath be warm or hot. A sense of warmth is first experienced, followed by increased vascular activity of the skin, the latter becoming red. Respiration is quickened, and the heart action increased, though the vessels lose tension. The body takes on heat, the radiation of which is prevented, and the temperature amounting in some persons, if the bath be hot, almost to a fever. The renal secretions are diminished, while those of the skin and lungs are augmented, through which the body loses weight. Unpleasant praecordial oppression, and a feeling of fullness in the head, with a sense of distension, dizziness, and faintness, are among its effects. If too prolonged, or too high in temperature, the hot bath may produce bleeding at the nose and lungs, cerebral congestion, or apoplexy. They are contraindicated where the cerebral vessels are known to be diseased. The hot bath is somewhat similar in its effects to the vapor, but is apt to prove dangerous in some constitutions. Dr. J. Chapman states that heat along the spine lessens the general circulation, overcomes congestion in all arts of the body, lessens fever, cheeks hemorrhage, and diminishes or suspends the menses.

Externally, water is frequently applied as a sedative in local inflammations, as quinsies, sore throats, ophthalmia, sprains and contusions, and as a means of restraining hemorrhage. Cloths wet with cold water and applied to the abdomen, have relieved severe pain in the bowels, retention of urine, etc. The cold dash or douche, has been successfully employed in delirium tremens, apoplexy, tetanus, hysteria, convulsions, obstinate constipation, congestive, bilious, and typhoid fevers. The wet sheet is much used to allay febrile and inflammatory conditions, and to promote diaphoresis. As an injection, it has been efficient in habitual constipation, and excessive tympanitic distension, as well as in dysentery. Applied warm it is an excellent application to erysipelatous inflammations. Ice and iced water, as local applications, are said to be very useful in burns and scalds; also in man cerebral affections. Prof. C. E. Brown-Sequard considered the application of cold to the spinal column to produce a contraction of blood-vessels by a reflex action, but if this action be very powerful, it will be followed by exhaustion and dilatation of the blood-vessels, and an actual increase of the amount of blood circulated in the cord. Dr. J. Chapman considered that ice applied upon the spinal column augments the general circulation, cheeks the cramp of voluntary and involuntary muscles, restrains the sickness of pregnancy, cures sea-sickness, and promotes menstruation. He stated to have used it successfully in epilepsy and other convulsive affections, in paralysis, tetanus, and in cerebro-spinal fever. His views have been published and are worthy of consideration. Locally, both cold and warm water are very useful in surgical procedures, particularly in sprains, bruises, contusions, etc., and the local warm bath is particularly valued in lacerated wounds and contusions. The application of cold water, snow or ice to frost-bites is well known.

The following are the temperatures at which baths are usually applied:

The VAPOR-BATH increases the action of the capillary vessels, causing excessive diaphoresis; it renders the skin pliable, relieves tension and rigidity of the joints, and may be usefully employed in rheumatism, cutaneous gout, profuse sweating from cutaneous debility, tardy or imperfect eruptions of the exanthemata, paralysis, dropsy, etc. It is of particular value in nephritis, and, directed into the mouth, in membranous croup. The Russian bath is a form of vapor bath in which the patient is subjected to the vapor of water at 35° to 43.3° C. (95° to 110° F). It should not be borne longer than a quarter of an hour, and the bath should be followed by a cold bath or the dashing of cold water over the body, associated with friction.

The vapor bath may be conveniently given, and in a very simple manner, by placing the patient between blankets, on a bed previously protected by a rubber sheet, and tucking the covering well around the head and shoulders, and down at the sides of the bed. Then, by means of rubber tubing, conduct the steam from a partially filled tea-kettle of boiling water, kept hot by placing the kettle upon an oil or other heating apparatus, into the space between the blankets. Care should be had that the jet of steam does not come in direct contact with the flesh. If the patient is able to sit up, a low stool may be utilized, and the patient covered with a blanket under which the jet of steam may be directed. Fresh lime is sometimes resorted to to raise a vapor, and is particularly of value in diphtheria and croup. The spirit vapor bath is referred to elsewhere.

The TEPID-BATH (29.4° to 33.3° C. [85° to 92° F.]) is useful in softening and removing the broken-down epithelium, as well as the sebaceous and sudoriferous secretions. It does not appreciably reduce temperature, and no reaction follows.

The WARM-BATH (33.3° to 36.6° C. [92° to 98° F.]) relaxes the system, lessens the activity of the circulatory and respiratory organs, ultimately somewhat diminishes the temperature of the body, and tends to tranquilize and occasion somnolency. It is useful in spasms and convulsions of children, retention of urine, nephritic pains, etc., and occasionally through its secondary effects in high inflammatory and febrile diseases, it will frequently prove advantageous. It should not, be used in cerebral and pulmonary affections.

The TEPID or WARM SPONGE-BATH is exceedingly useful in many febrile conditions, for when employed in this manner, the skin is well relaxed, and the radiation of heat is not prevented as by immersion. There can be no doubt but that sponging the head constantly with warm water, drawing the sponge back and forth, and at the same time fanning the parts, is far more effective and safe in cases of insolation, cerebro-spinal inflammations, etc., than is the local application of cold water or ice, which probably does little more than chill the surface.

The COLD SPONGE-BATH (12.7° to 26.6° C. [55° to 80° F.]) is frequently employed by some to reduce temperature and allay nervous excitement; the anterior surface of the body being first sponged, and then the dorsum. Harrington (N. Y. Med. Times, 1897) advises the addition of 20 to 35 per cent of alcohol to increase the antipyretic value of the bath. The patient is then to be covered with a light sheet and blanket.

Cold water may also be used by affusion, shower-bath, or douche, and will be found tonic, stimulant, or sedative, according to its temperature, the length of time it is used, and the state of the body.

In addition to the above uses of water, it has likewise other employments, as follows:

The WET-SHEET PACKING, or Lein Tuch of the Germans. A mattress of cotton, hair, or straw, has spread over it three or four large, thick comfortables, and over these one or two soft flannels. A linen sheet, having been previously dipped in cold water, or for very delicate persons in tepid or even warm water, is lightly wrung out, so as not to drip, and spread over the whole, having under it one or two pillows for the head. The patient is made to lie upon these on his back, and is quickly and snugly enveloped in the wet sheet, over which is placed the flannels and blankets, or a light feather bed may be thrown over the top, in case comfortables are not plenty. Care should always be taken to turn the clothing snugly and smoothly around the feet and neck; and if the feet remain cold, bottles of hot water should be placed to them. Headache is prevented or removed by the application of cold wet cloths applied to the head.

The time for remaining thus "packed" varies in different cases, averaging from half an hour to an hour, depending on the effect; the body should become comfortably warm before being removed. A disagreeable sensation of cold is first experienced, which is soon followed by a pleasurable warmth over the whole surface, and sometimes copious perspiration, though this last is not always indicated. On coming out of the "pack," the plunge, the douche, rubbing wet sheet, or towel washing, are to be employed, as the case may require. If the patient experiences a chill after coming out, a thorough rubbing, followed by 15 or 20 minutes' dry packing, will usually obviate all injurious consequences. The process of packing should never be continued so long as to cause headache, languor, muscular debility or giddiness.

This is said to act as a sedative, reducing the heat of the body, and excessive arterial action, and as an alterative, correcting morbid secretions, and restoring healthy ones. In fevers and all acute inflammatory disorders, it may frequently be renewed according to the degree of fever or inflammation, until the temperature and circulation are reduced to the natural standard, and the skin becomes soft and perspirable. Much sweating is not usually to be desired. In chronic diseases, it removes internal congestions, develops external circulation, produces a healthy condition of the skin, and may be used in many forms of this class of maladies. If carelessly attended to the wet sheet may give rise to serious difficulties.

When the wet sheet is applied to the trunk of the body only, as in cases of feeble persons, where there is not sufficient vitality for the whole sheet, or for other purposes, it is termed the "HALF-PACK"-SHEET.

The RUBBING WET-SHEET is a large sheet dipped in water, and wrung out so as not to drip. It is then suddenly thrown around the patient's body, enveloping him closely from the neck to the feet, and the body is then rubbed for about 5 minutes by the hands of the attendants on the outside of the sheet. It is to be followed by rubbing with dry towels. This produces a strong and general determination to the whole surface, and is applicable in all cases where a strong determination is desired from internal organs or surfaces to the skin. It will be found valuable in the early stages of bowel complaints, diarrhoea, dysentery, colic, fevers, etc.; it is likewise useful for exhaustion following mental exertion, many forms of insanity, delirium tremens, night-sweats, wakefulness, nightmare, etc. When the sheet is employed drippingly wet (the dripping sheet), a large tub or pan is necessary for the patient to stand in, to avoid wetting the floor.

The DOUCHE is the application of a stream of cold, tepid, or warm water, from a greater or lesser height, and continued for a time indicated by its effects. The force of the stream and time of application should be carefully adapted to the strength of the patient. Very nervous persons, and those subject to determinations to the brain, should resort to it with extreme caution. A strong douche should never be applied to the head, nor should it be long continued on any one spot along the vertebral column. A douche may be vertical, oblique, horizontal, or ascending. The most common are in perpendicular streams 1 or 2 inches in diameter. Its effect is to arouse the activity of the absorbent system, and is hence very useful in gout, rheumatism, paralysis, chronic enlargements of the viscera, tumors, etc. The ascending douche will be found beneficial in piles, uterine displacements, prolapsus ani, constipation from debility, chronic enlargement of the prostate gland, impotency, etc. The stream maybe ½ to 1 inch, and should not be forcible enough to cause absolute pain nor serious inconvenience. Warm-water douches are for the purposes of producing relaxation of the muscles of the part acted upon, and are hence useful in rigidity of the muscles, painful swellings, chronic inflammation of the joints, neuralgia, spasmodic and bilious colic, retention of urine, amenorrhoea, uterine rigidity, leucorrhoea, metritis, renal colic, etc. In some cases it should be followed by a momentary cold dash. Prof. Brown-Sequard considered the Cold douche or Cold shower bath, useful in white softening and reflex paraplegia; and the Hot douche (37.7° C.) [100° F.], when applied to the spinal column over the painful part, very efficient in congestion or inflammation of the cord, but injurious in white softening and reflex paraplegia.

The HIP or SITZ-BATH is a common tub, in which the patient sits so as to have the water cover the hips and lower parts of the abdomen. A vessel made for the purpose, with a back to rest against, is more convenient. The water may be of any temperature, and the time of application varies from 5 to 30 minutes.

According to its application it is tonic, derivative, or sedative. Tonic when applied from 5 to 15 minutes; derivative when extended from 15 to 30 minutes; and sedative according to its effects. Derivative hip baths should not be carried to the point of producing paleness or lividy of the lips, shiverings, nausea, faintness, or headache, and according to the effect desired, and the coldness, torpor, and debility of the patient, indicate that the quantity of water should be lessened, or its temperature elevated. It is useful in debility, irregularity, obstruction, and torpor of the organs of the pelvis and lower part of the abdomen. A blanket is generally thrown around the patient during this bath.

The SHALLOW-BATH is a circular, or oval tub, raised about 12 inches from the floor, and with water in it from 4 to 6 inches deep. The patient sits in this, while the attendant sprinkles his head, and rubs his chest, abdomen, and back. It may be employed from 1 to 30 minutes, and should be followed by a good, dry rubbing. It is used at a temperature from 15.5° to 23.8° C. (60° to 75° F.), and is excellent in cutaneous affections, and other cases where a mild derivative, or moderately sedative influence is desired.

The PLUNGE-BATH may be any vessel or place, the water being from 12.7° to 18.3° C. (55° to 65° F.), which will allow the patient to plunge into it, head or feet foremost as he fancies, or to quickly immerse the whole body up to the neck. The time for remaining in it varies from a few seconds to 2 or 3 minutes, or in high fever, to 10 or 15 minutes. It is generally taken after the sweating process, and after the wet sheet, when the patient can bear the exertion; in these cases the sheet is not to be removed until at the plunge. It is very useful in all febrile and chronic affections, but should be employed with care, or avoided altogether in consumptive and dropsical patients, and those laboring under organic diseases of the heart.

These are the principal applications of water in practice; yet there are several others of a useful character, as the Foot-bath, the Head-bath, the Shower-bath, etc., the modes of application of which are generally well understood, as well as their effects. Cold water may likewise be used in form of a bandage or girdle, by applying one or more folds of linen wet in cold water, to the part affected, or around the abdomen, and covering it with a dry cloth or other material to retain the heat. The wet girdle or abdominal wrapper or compress, is applied around the abdomen in all acute diseases of the abdominal viscera. The bandages are applied warm or cold, according to the indications they are intended to fulfil. The application of hot water by means of wetted cloths laid upon the parts, is very effective in painful conditions, as in dysmenorrhoea, various forms of colic, and neuralgia, and to inflammatory swellings. The rubber water bottle is an excellent apparatus for the application of moist heat.

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.