WATER. - I. A. IN THE SCIENCES. - Every form of life, including the human, unfolds in an aqueous environment. Some animals, such as jellyfish, contain more than 95% water: even in the human organism the quantity of water is considerable and decreases with the progress of development and aging: 97.5% in the embryo at one and a half months, 82.9% in the fetus at four months, 71.2% in the newborn, 64.5% in the adult, 58.3% in the elderly. All the chemical reactions of the organism occur in water; and even the respiration of terrestrial animals, man included, is made possible insofar as the oxygen of the air dissolves in the aqueous film that moistens the pulmonary alveoli or other surfaces that perform a similar function (v. BIOCHEMISTRY, RESPIRATION). Interesting are the mechanisms by which living beings appropriate the water contained in the environment, defend themselves against excessive loss of it, and those by which they repeatedly exploit the same mass of water for the transformation of considerable quantities of organic substance. Indeed, large quantities are required for the various vital functions: for the formation of one kg. of dry organic substance, plants need from 500 to 700 liters of water; and for the formation of a chick, the limited quantity of water contained in the egg is exploited innumerable times.
Knowledge of the physical and chemical properties of water is important not only for chemistry and biology but also for the entire economy of our planet, to explain its geological history and its current geophysical aspect. The erosion of eruptive rocks, the formation and subsequent transformations of sedimentary rocks, the phenomena of the troposphere and many others are linked to the presence or action of water; and to water, as nourishment for man, as a condition for plant life, and as a means of riverine and maritime communication, are linked the distribution of life on earth and the formation, migration, and cultural development of human groupings.
The molecule of water is constituted by an atom of oxygen bound to two atoms of hydrogen which form with the first an angle of 104°31'. In such a combination the hydrogen atoms assume a positive character, that of oxygen a negative one, so that the molecule presents electrical polarity which, together with more complex reasons of a quantum-mechanical order, is the cause of the association between molecules and, in definition, of some very important and singular anomalies in the physical properties of water, which will be recalled here.
Water has a density (1.000) notably lower than that which it should have (ca. 1.840) in dependence on its molecular radius (1.40 Å; one Angstrom = 1/100,000,000 of cm.) if its structure were not associated or were that of ideal monoatomic liquids. It is a general rule that the volume of bodies decreases with the lowering of temperature and in the passage from the liquid to the solid state. Water, too, on cooling contracts but only down to 4°; continuing the cooling it dilates slightly until solidification, which is accompanied by a notable increase in volume: 100 volumes of water at 0° (density 0.999868) yield ca. 100 of ice at 0° (density 0.9167). Such facts are explained: 1) by the formation, on cooling, of polymer molecules (associations of two or more simple molecules) at the expense of those monomeric (or simple); 2) by the existence of a crystalline structure even in common liquid water; 3) by the particular crystalline structure of liquid water and of ice, on account of which the molecules, in associating into crystalline groupings, assume a looser arrangement, that is, they come to occupy a greater volume. From this there follows a consequence of great importance in nature: the ice that forms on seas and lakes, being lighter than water, does not sink to the bottom but remains on the surface; and, being a poor conductor of heat, it prevents the freezing of the water beneath it: thus the solidification of immense masses of water is avoided and marine and lacustrine life is made possible beneath the ice crust. When water freezes in a confined environment it can develop strong pressures capable even of bursting steel bombs several centimeters thick: thus is explained the action of frost in producing the crumbling of rocks.
Water crystallizes in the hexagonal system (CRYSTALS): groups of crystals in star-like form are observed in snow.
It is calculated that if water did not give molecular associations but had the constitution of ideal liquids it should melt at 130° and boil at 100°; at ordinary temperatures liquid water could not exist and all the water of our planet, instead of being found in seas and rivers, would constitute the greater part of the atmosphere. Even the values of specific heat (close to 1.000 for all ordinary temperatures), of latent heat of fusion (79.2 at 0°), of latent heat of evaporation (595 at 0°, 585 at 20°, 574 at 40°, 540 at 100°) (v. THERMOLOGY; PHYSICAL UNITS) are higher than the respective magnitudes of almost all inorganic and organic substances. This must be attributed not so much to the associated state of the molecules as to the exceptionally low value of the molecular weight of water (18.016). Indeed, the same magnitudes referred to the gram-molecule and obtained by multiplying those specific (expressed in cal/g or Cal/kg) by the molecular weight are quite normal when compared with those of other substances. Because of the high values of specific heat and of latent heats of fusion and evaporation, water is a great thermal regulator of the surface of our planet. The high value of the surface tension of water (mg. 7.692 cm. at 0°, 7.086 at 40°) together with the capacity to adhere to the surface of many bodies (wetting) is important in geology and in biology for the phenomena of imbibition, capillarity, swelling, etc.
The particular mode of association of its molecules partly justifies the high value of the dielectric constant of water (88 at 0°, 80.5 at 20°, 73.4 at 40°, 70.5 at 50°). This constant (v. ELECTROLOGY) represents by how much the attractive force of two electric charges of opposite sign is reduced when, instead of a vacuum (practically air), water is interposed, and it appears in the denominator in the classic formula of Coulomb. The high value of this constant explains the strong ionizing power of water: salts, acids, and bases dissolved in it undergo electrolytic dissociation into cations (or positive ions) and anions (or negative ions). In their turn, such ions, precisely because of their electric charge and the polarity of the water molecules, become hydrated, that is, they bind more or less loosely and energetically to an indeterminate number of water molecules; and the ions thus hydrated assume some characteristics of water itself: this explains the high solvent power of water for most substances, especially those of a saline nature. Water is also a good solvent for many non-ionizable substances, and this is explained by the presence in the molecule of these substances of: 1) partially polar bonds; 2) an asymmetrical distribution of electric charges; 3) groupings that react with water forming polar bonds: all circumstances that favor the formation of associations between the molecules of the solute and those of the solvent.
In addition to being ionizing as a solvent, water itself is ionized: one litre of water at 22° contains 10^-7 gram-molecules of dissociated water according to the equation \( H_2O \rightleftharpoons H^+ + OH^- \); and since one litre of water contains 1000:18 = 55.6 gram-molecules, it results that there is one dissociated molecule for every half billion molecules (0.556·10^9). At 0° the dissociation of water is 1.3 and at 100° about 8 times that measured at 22°. To this, however modest, dissociation must be attributed water’s capacity to participate in many chemical reactions, some of which are fundamental to life. Water is in fact not only an essential constituent of living cells in every form of life but also participates, no less than other constituents, in remarkable biophysical and biochemical reactions. The imposing process of carbon fixation carried out by green plants (v. FOTOSINTESI CLOROFILLIANA) occurs with the intervention of water, the oxygen of which is eliminated as molecular oxygen gas while the hydrogen of the same reduces carbon dioxide CO_2 with the formation of water and a series of intermediate products still (1948) poorly understood, from which carbohydrates (starch and sugars) are ultimately formed. Water also participates in the oxidation-reduction phenomena that constitute cellular respiration.
Ordinary water is a mixture of about 5000 parts of H_2O and one part of heavy water D_2O: the latter differs from the former by having, in place of hydrogen of atomic weight 1, its isotope, heavy hydrogen or deuterium, of atomic weight 2 (it would be more accurate, however, to say that ordinary water is a mixture of about 5000 parts of H_2O and 2 parts of HDO water in which one oxygen atom is united with one hydrogen atom and one deuterium atom). The content of heavy water in natural waters is not uniform. Heavy water has been obtained in a state of purity: it has a density (d 20°/20°) of 1.10714, boils at 101°.42, solidifies at 3°.82 and has its maximum density at 11°.6.
CUSCO: Tofolli
2. IN NON-CHRISTIAN RELIGIONS
Water, which by its natural property serves to cleanse all filth, was chosen from the most remote times by all peoples as a symbol of an interior purifying action. The mystery of its origins within the bowels of the earth, its voice ranging from a gentle murmur to a mighty roar, its mobility like that of a living thing, its breath revealed in evaporation, its power to irrigate—whether it gushes from the earth or falls from the sky—have always caused it to be regarded as a living and beneficent force. It is present in various forms: in the sea, in lakes, in rivers or torrents, and all these elements have been deified and honored with cult; but especially the water that springs from the ground—called by Seneca (Quaest. nat., 3, 8) “viva sua natura” to distinguish it from that which falls from the sky, “caelestis seu collectiva”—is invested with sacred value and at the same time with purifying, fertilizing, and divinatory power among various peoples.As a fertilizing element, water has everywhere been the object of cult. The Greeks expressed this power in various myths, where nymphs, patrons of springs, signify by their very name its power of fertility. As a divinatory element, water acts both through the murmur of springs, the casting of objects into it, and ingestion: at Delphi, the Pythia, before ascending the tripod, tasted the water of the sacred springs Castalia and Cassotis. The divinatory power was revealed especially in cases of ordeal or “judgment of God” when it was a matter of judging the guilt of an accused person or the legitimacy of a birth, etc. The unharmed state of an individual thrown into the water was proof of his innocence. As a purifying element, water has no equal in its capacity not only to wash but also to carry away impurities as it flows. Naturally, the number and manner of ablutions vary in different rituals, according to the gravity of the fault or the preparation necessary to approach or touch sacred things, to receive an initiation, etc. Indeed, in baptism, water is the matter that symbolically expresses the spiritually renewing power of Christian initiation, the cancellation of the stain of original sin and, if necessary, of actual sins. A particular case of the purifying power of water is represented by healing or thermal waters, discussed below.
As a bestower of oblivion and thus, in its own way, a healer, water occupies a broad place in myths of the afterlife: one need only think of the water of Lethe (whence the word lethargy), which induces the sleep of forgetfulness at the entrance to Hades. The placement of the underworld (where neither rivers nor lakes are lacking), situated in distant places reached by boat, may have been suggested by the experience of primitive navigation on rivers beyond the horizon or on the boundless sea.
Nicola Turchi
3. HOLY WATER
It is the most common sacramental (v.) of Catholic liturgy. Moses (Num. 19, 9-18) prescribes it mixed with the ashes from the burning of the sin-offering, to cleanse those who had contracted legal impurity. Once worship was established in Jerusalem, the water from the pool of Siloam served for the sacred uses of the Temple.As regards Christian liturgical use, a distinction must be made between the water used exclusively for conferring baptism—prepared on the vigil of Easter and Pentecost with the infusion of the oil of catechumens and chrism (baptismal water)—and the water simply blessed (holy water), which the Church commonly uses, prepared by mixing it with salt while reciting appropriate prayers. This mixture of salt, a symbol of incorruptibility, was inspired not so much by the biblical episode of the prophet Elisha (2 Kings 2, 20-21), who healed the waters of Jericho with salt, as by the widespread belief that salt possessed a repulsive power against demons (A. Franz, I, p. 133).
The preparation of holy water, according to the prescriptions of the Roman Ritual, involves: a) an exorcism over the salt and the water to purify them from every impure or harmful influence; b) a blessing upon both, so that the salt “may be to all who taste it a health for soul and body” and the water “may receive the power of divine grace to drive away demons, to heal diseases, so that whatever in the homes and places of the faithful is sprinkled with this water may be preserved from all filth and freed from every evil.”
The present formulas were already contained in liturgical books by the end of the 7th century (Sacramentarium Gelasianum, III, 75-76; L. Muratori, Lit. Rom. Vet., I, 738-40), except for the formula of the mixture (“Committo, etc.”) introduced after the 9th century.
The use of holy water is attested in the East from the 3rd century, but the Greek Church always excludes salt when blessing II. In the West its existence is not certainly attested before the 6th century, the period of the oldest
The editorial staff of the *Liber Pontificalis*. This work attributes its institution to a decree of Alexander I (105–106?): “Hic constituit aquam sparsionis cum sale benedici in habitatis hominum” (Lib. Pont., ed. L. Duchesne, I, 127). The decree is certainly apocryphal. It is hard to believe that the Church in the second century would have adopted so characteristically pagan a usage, which Tertullian and other Fathers regarded as magical. Later, however, when Christianity had won over the masses, it could allow even such an intrinsically harmless usage as the lustral water to be sanctified, along with many others. In any case, holy water was first blessed in houses for their purification; later the rite was performed in churches for similar purposes. For example, Pope Vigilius in 538 assumes it as a necessary element for the consecration of a new church. The seventh Roman order of the same period (cf. M. Andrieu, *Les Ordines rom.,* I: *Les Manuscrits*, Louvain 1931, p. 168) permits the faithful on Holy Saturday to take water from the baptismal font—the water already consecrated with chrism—to sprinkle it in homes and fields. Later this was expressly forbidden, and only drawing water before the priest infused the chrism was allowed, as the Roman Missal rubric still prescribes. The Latin Church still makes very extensive use of holy water, especially in exorcisms and in the blessing of persons and objects. Its use is regulated by the norms given in the Roman Ritual. A solemn blessing of water, in memory of Christ’s baptism, is performed on Epiphany (January 6).
From the Greek Church. In the past, a similar blessing was also performed in many Latin churches of southern Italy, Magna Graecia, the Venetian coast, Aquileia, and even Rome itself (cf. C. Respighi, *La bened. sol. dell’a. nell’Epifania*, in *Rass. Greg.,* 10 [1911], p. 54). Generally, the formulary adopted for this rite in most of the above churches had nothing in common with the official text of the Byzantine Church. Wilmart (in *Rev. Bénéd.,* 29 [1912], p. 29), who published an ancient recension (9th–10th century, apparently for an Italian church), notes the characteristic ecclesia contained therein: “Tu Jordanis aquas sanctificasti hodie, e coelo mittens Spiritum tuum Sanctum... Tu ergo, piissime Rex, adesto nunc per adventum Sancti tui Spiritus et sanctifica aquam istam.” The blessing concluded with the *Te Deum*.
A particular holy water, compounded of salt, wine, and ashes, is prescribed by the Roman Pontifical for sprinkling the external and internal walls of a church with a branch of hyssop in the solemn rite of consecration. This water, in rituals after the year 1000, is called *gregoriana*, perhaps because St Gregory alludes to it in his famous letter to St Augustine of Canterbury: “Aqua benedicta fiat, et in eisdem fanis aspergatur” (Epist., IX, 71). But St Gregory does not specify what ingredients went into its composition. The Gelasian Sacramentary (I, 78; cf. L. Muratori, *Lit. Rom. Vetus*, I, 610) contains a formula for blessing a mixture of water and wine for the dedication of a new church, but says nothing about the other two elements, salt and ashes. All three, however, appear in the liturgical use in the *Ordo dedicationis ecclesiae* published by G. Bianchini (*Anast. Bibliot. Opera*, vol. III) from a manuscript of the Chapter Library of Verona written in 830 AD. This represents pure Roman rite. The blessing of the *gregoriana* water is reserved to the bishop.
4. Salutary Water
An old medical interpretation, still followed by many historians of medicine, sees in lustral rites mere veiled hygienic precepts, whereas in fact they must be regarded as ritual acts whose purpose is to restore lost purity. Hence they often coincide with what today would be called hygienic precepts. In these rites, water plays the principal role: one need only recall the river and spring baths found in all civilizations and religions. A spring was to be found in the Asclepieia; it was the sacred water of the god, an essential condition for healing. Countless shrines, small temples, and votive altars were built near springs, especially mineral waters, credited with special therapeutic powers. This is the point of transition between the recognition of water’s natural virtues and its sacralization.With the coming of Christianity, the cult of healing waters could not be forbidden to the popular mentality, which continued to flock to certain springs and fountains or to use this or that water once sanctified by one or another deity for curative purposes. Since this practice could not be suppressed, the original reason for its beneficial effect was changed: the ancient healing waters were credited with new power through proximity to martyrs’ bodies or through miraculous events associated with them.