Acidum citricum. London.-Citric acid. Take of lemon juice a pint; prepared chalk an ounce, or sufficient to saturate the juice; diluted sulphuric acid nine fluid ounces. Add the chalk gradually to the lemon juice heated, and mix them; then pour off the liquor. Wash the citrate of lime which remains in repeated quantities of warm water, and then dry it. Pour on the dried powder the diluted sulphuric acid, and boil for ten minutes; then strain the liquor through a linen cloth by strong pressure, and filter it through paper. Evaporate the filtered liquor with a gentle heat, so that crystals may form in cooling. In order that the crystals may be obtained pure, let them be dissolved in water a second and a third time, filtered each time, and set apart for crystallisation.

In this process it is obvious enough that the lime of the chalk unites with the citric acid existing in the lemon juice, and forms an insoluble citrate of lime, which is decomposed by the sulphuric acid, leaving the citric acid free.

Qualities. The crystals should be white and transparent; they are without smell, but are of a caustic sharp taste. They are soluble in water. When adulterated with tartaric acid, the adulteration may be detected by addition to the solution of them of nitrate, sulphate, or muriate of potassa, or saturating it with carbonate of potassa, when, if the tartaric acid be present, an insoluble super-tartrate of potassa will appear in small bright crystals; should citrate of lime still remain among the crystals, it is detected by dissolving them in water, saturating the solution with ammonia, and adding to it some oxalate of ammonia, which will precipitate the lime. If sulphate of potassa be present, it will be discovered by the solution yielding a precipitate with muriate of barytes, this being insoluble in muriatic acid.

Medical properties. The same as lemon juice; in some particulars being superior, in others inferior. It wants the freshness of the acid immediately from the fruit, but it is much more convenient for extemporaneous use than common lemon juice. It is said to equal this last in strength when dissolved in eight waters. Nine drachms and a half of the crystals to a pint of water is the proportion that Dr. Thomson gives for the formation of lemon juice, and we copy from him the following table, showing the quantity of citric acid required to decompose one scruple of the alkaline salts mentioned in it.

equally useful in febrile and inflammatory com plaints.

Acidum muriaticum. London.-Muriatic acid. Take of dried muriate of soda two pounds, sulphuric acid twenty ounces by weight, distilled water a pint and a half. First mix the acid with half a pint of the water in a glass retort, and add the muriate of soda after the mixture is cold. Pour the rest of the water into the receiver; then having fitted on the retort placed in a sand bath, distil the muriatic acid over into this water with the heat gradually raised to redness.

The specific gravity of this acid is 1.160, and 100 grains of it are saturated by 124 grains of the subcarbonate of soda in crystals.

Edinburgh.-Take of muriate of soda which has been previously exposed to a red heat, sulphuric acid and water of each two pounds. Pour the acid mixed with eight ounces of the water and cooled upon the muriate of soda in a glass retort, to which a receiver is to be adapted containing the remainder of the water; then distil from a sand-bath with a moderate fire. In a short time the vessels may be luted together, and the distillation continued to dryness. The specific gravity of this acid is 1.170.

'These processes were formerly explained by saying that the decomposition of the muriate of soda is affected by the superior affinity of sulphuric acid for soda, aided by the affinity of the muriatic acid for soda being weakened by the heat, which favors its tendency to assume the elastic form, in which state it passes over into the receiver, and is there condensed by the water. But, as the doctrine of chlorine is now admitted, we must adopt the following explanation of Sir Humphry Davy, who regards dry common salt as a compound of thirty-six parts of chlorine and twenty-four of sodium, and consequently containing neither muriatic acid nor soda. In the processes of the Pharmacopoeias, therefore, for obtaining muriatic acid, the water of the sulphuric acid is decomposed, its oxygen unites to the sodium, and forms soda, which, combining with the sulphuric acid, produces a sulphate of soda; while the hydrogen of the decomposed water combines with the chlorine and forms hydrochloric acid, or muriatic acid gas: a gaseous fluid consisting of equal volumes of hydrogen and chlorine, or by weight, of hydrogen 27, chlorine 97-3, in 100 parts, which dissolving in the water contained in the receiver constitutes the liquid acid. The residue of the process is sulphate of soda with an excess of acid; to separate which, without breaking the retort, boiling water may be poured into the retort after its contents have cooled down to 212°. CHEMISTRY and ACID.

See

Qualities. The liquid acid thus obtained is nearly colorless, with a very caustic taste and a pungent odor. According to the new nomenclature the muriatic acid of the shops is hydrochloric acid, or, to retain the common name, hydro-muriatic acid. The real acid contained in the liquid acid is a compound of equal volumes of chlorine and of hydroger. The fluid muriatic acid found in the shops often contains sulphuric acid with small portions of iron and sometimes copper; the first is diluted by di

earth, and whether discovered by observation or experiment.

PHAER (Thomas,) M. D., an English physician, born in Pembrokeshire. He graduated at Oxford in 1539. He published several tracts on diseases and their remedies; and was also celebrated as a poet. He translated nine books and part of the tenth into English verse; and died in

1560.

PHÆSANA, an ancient town of Arcadia. PH/ESTUM, in ancient geography: 1. A town of Crete; 2. A town of Macedonia.—Liv. 36, c. 13.

Minos and Pasiphae; she married Theseus, by whom she was the mother of Acamas and Demophoon. They had lived for some time in conjugal felicity when Venus, who hated all the descendants of Apollo, because he had discovered her amours with Mars, inspired Phædra with the strongest passion for Hippolytus, the son of Theseus, by the amazon Hippolyte. This passion she long attempted to stifle, but in vain; and therefore, in the absence of Theseus, she addressed Hippolytus with all the impatience of desponding love. He rejected her with horror and disdain. She, to punish his coldness and refusal, at the return of Theseus, accused Hippolytus of attempts upon her virtue. He, without hearing Hippolytus's defence, banished him from his kingdom, and impland Neptune, who had promised to grant three of his requests, to punish him in an exemplary manner. As Hippolytus fled from Athens, his horses were suddenly terrified by a sea monster, which Neptune had sent on the shore; and he was thus dragged through precipices and over rocks, trampled under the feet of his horses, and crushed under the wheels of his chariot. When his tragical end was known at Athens, Phædra confessed her crime, and hung herself in despair. She was buried at Trazene, where her tomb was still to be seen in the age of Pausanias, near the temple of Venus, which she had built to render the goddess propitious.

PHEDRIA, a small town of Arcadia.-Paus. PHEDRUS, an ancient Latin writer, who composed five books of fables, in Iambic verse. He was a Thracian; and his being called Augustus's freedman, in the title of the book, shows that he had been that emperor's slave. The fables of Phædrus remained buried in libraries, altogether unknown to the public, until the close of the sixteenth century.

PHEDRUS (Thomas), a professor of eloquence at Rome, early in the sixteenth century. He was canon of Lateran, and keeper of the library in the Vatican. He owed his rise to the acting of Seneca's Hippolytus, in which he performed the part of Phædra; whence he got the name of Phædrus. He died under the age of fifty. Janus Parrhasius gives a list of several of his works which were almost ready for public view.

PHEDYMA, the daughter of Otanes, one of the seven Persian conspirators, who, being married to the false Smerdis, discovered his imposture to her father, by his want of ears, which had been cut off by Cambyses. See PERSIA.

PHENARETE, the mother of Socrates the philosopher. She was a midwife by profession. PHANIAS, a peripatetic philosopher, a disciple of Aristotle. He wrote a History of Tyrants. Diog. Laert.

voy.

PHENNA, one of the Graces.-Paus. ix. 35.
PHÆNOMENON, n. s. See PHENOMENON.
This has phænomena in the plural; Gr. pavoue
An appearance in the works of nature; a
remarkable appearance.
The paper was black, and the colors intense and
thick, that the phænomenon might be conspicuous.
Newton.

PHENOMENON, in philosophy, denotes any remarkable appearance, whether in the heavens or

PHAETON, in fabulous history, the son of Phoebus and Clymene, one of the Oceanides. Venus became enamoured of him, and, entrusted him with the care of one of her temples. This rendered him vain and aspiring; and, having obtained from his father the direction of the chariot of the sun for one day, he was unable to guide the fiery steeds; and, loosing the reins, Jupiter, to prevent his consuming the heavens and earth struck him with a thunderbolt, and hurled him from his seat into the river Eridanus or Po.

His sisters Phaetusa, Lampetia, and Phoebe, lamenting his loss upon its banks, were changed by the gods into black poplar trees, and their tears into amber; and Cycnus, king of Liguria, also grieving at his fate, was transformed into a swan. The poets say that, while Phaeton was driving the chariot of his father, the blood of the Ethiopians was dried up; and their skin became black. The territories of Libya were also parched up; and ever since Africa, unable to recover her original verdure and fruitfulness, has exhibited a sandy desert. Some explain this poetical fable thus:-Phaeton was a Ligurian prince, who studied astronomy, and in whose age the neighbourhood of the Po was visited with uncommon heats.

PHAETON, in ornithology, a genus of birds belonging to the order of anseres; the characters of which are:-The bill is sharp, straight, and pointed; the nostrils are oblong, and the hinder toe is turned forward. There are two species, viz.

1. P. æthereus, the tropic bird, is about the size of a partridge, and has very long wings. The bill is red, with an angle under the lower mandible. The eyes are encompassed with black, which ends in a point towards the back of the head. Three or four of the larger quillfeathers, towards their ends, are black, tipped with white; all the rest of the bird is white, except the back, which is variegated with curved lines of black. The legs and feet are of a vermilion-red. The toes are webbed. The tail consists of two long straight narrow feathers, almost of equal breadth from their quills to their points. The name tropic bird,' says Latham, given to this genus, arises from its being chiefly found within the tropic circles; but we are not to conclude that they never stray voluntarily, or are driven beyond them; for we have met with instances to prove the contrary.' There are several varieties:-1. One called by Latham the white tropic bird. It is less than the preceding, and is found in as many places. The plumage is in general a silvery white. 2. The yellow tropic

bird is another variety, the plumage being a yellowish white. These differences, Mr. Latham thinks, arise merely from age, if they are not the distinguishing mark of sex. 3. The black-billed tropic bird is smaller than any of the former. The bill is black; the plumage on the upper part of the body and wings is striated, partly black and partly white: before the eye there is a large crescent of black; behind it is a streak of the same; the forehead and all the under parts of the body are of a pure white color; the quills and tail are marked as the upper parts, but the ends of the first are white, and most of the feathers of the last are marked with dusky black at the tips; the sides over the thighs are striated with black and white; the legs are black. 4. The red-tailed tropic bird is in length about two feet ten inches, of which the two tail feathers alone measure one foot nine inches. The bill is red; the plumage white, tinged with an elegant pale rose-color; the crescent over the eyes is somewhat abrupt in the middle; the ends of the scapulars are marked with black. This variety is distinguished by two middle long tailed feathers, which are of a beautiful deep red color, except the shafts and base, which are black: the sides over the thighs are dusky; and the legs are black.

2. P. demersus, the red footed penguin, has a thick, arched, red bill; the head, back part of the neck, and the back, of a dusky purplish hue, and breast and belly white; brown wings, with the tips of the feathers white; instead of a tail, a few black bristles; and red legs. It is found on Penguin Isle, near the Cape of Good Hope, is common all over the South Seas, and is about the size of a goose.

PHAETONTIADES, the sisters of Phaeton.
See PHAETON.

PHAETUSA. See PHAETON.
PHEUS, a town of Peloponnesus.
PHAGEDE'NA, n. s.

Fr. phagedenique ; PHAGEDEN'IC, adj. Gr. φαγέδαινα ; from PHAGEDE NOUS. Spayw, to eat. A virulent ulcer: phagedenic and phagedenous mean corrosive; eating into the flesh.

A bubo, according to its malignancy, either proves easily curable, or terminates in a phagedenous ulcer with jagged lips. Wiseman.

When they are very putrid and corrosive, which circumstances give them the name of foul phagedenick ulcers, some spirits of wine should be added to the fomentation. Sharp. Phagedenick medicines are those which eat away fungous or proud flesh. Dict. PHAGEDENIC MEDICINES are those used to eat off proud or fungous flesh; such as are all the caustics.

PHAGEDENIC WATER, in chemistry, denotes a water made from quicklime and sublimate, efficacious in the cure of phagedenic ulcers. PHAGESIA, an ancient festival among the Greeks; observed during the celebration of the Dionysia; so called from the payay, good eating, that then universally prevailed.

PHALACRINE, an ancient village of the Sabines, where Vespasian was born.--Seut. PHALENA, in entomology, the moth, a genus of insects of the order lepidoptera, having the antennæ gradually tapering from the base to the

tips; tongue spiral; jaws none; wings, when at rest, generally deflected.

The caterpillars of this genus vary much as to size, and considerably as to their shape and number of feet. It is remarkable that caterpillars of almost every species of this genus are found with ten, twelve, fourteen, and sixteen feet. The last are the most common. See ENTOMO

LOGY.

Moths fly abroad only in the evening, and during the night, and obtain their food from the nectar of flowers. The larva is active and quick in motion, mostly smooth, more or less cylindrical, and it preys voraciously on the leaves of plants. The pupa is torpid or quiescent, more or less cylindrical, pointed at the tip or at both ends; and is generally enclosed in a follicle. The following are the principal divisions of this tribe, according to the Linnæan system. Of the species there are upwards of 1500:

1. Bombyr. Antennæ filiform; two feelers, which are compressed and reflected; tongue short, membranaceous, obtuse, and bifid; the larva is sixteen-footed, often hairy; the pupa is pointed at the tip. a. Wings expanded.

4. Hyblea. Antennæ setaceous; feelers projecting, compressed, dilated in the middle; the lip is projecting and acute.

5. Hepialus. Antennæ moniliform; feelers two, reflected, hairy, between which is the rudiment of a bifid tongue; the larva is sixteen-footed, feeding on the roots of plants; the pupa is folliculate, cylindrical, and pointed at the tip.

6. Cossus. Antennæ short, filiform; two feelers, very short, cylindrical, reflected.

7. Pyralis. Antennæ filiform; the insects of this division have likewise two feelers, which are equal and almost naked; they are cylindrical at the base, the middle is dilated into an oval, and subulate at the tip; the tongue is projected, setaceous, and bifid; the wings are very obtuse, and slightly curved at the exterior margin; the