Page images
PDF
EPUB

vinegur ; when purified by distillatiou, it the plant has been called bastard pellitory, assumes the name of distilled vinegar, usual- and, on account of the form of the leaf, ly called acetous acid: when concentrated goose-tongue: the powder of the dried as much as possible by certain processes, it leaves, used as snuff, 'provokes sneezing, is called in the shops radical vinegar; but whence the name: in Siberia a decoction by chemists it is denominated acetic acid of the whole herb is said to be successfully One hundred parts of acetic acid are con used in internal hemorrhages: of this plant posed of 50.19 oxygen

there is a variety with double flowers, called 13.94 hydrogen

batchelor's buttons; it flowers in July and 35.87 carbon

August, and makes a tolerable appearance :

--and the millefolium, common M. or yar100.00

row; abundant in pastures and by the sides ACETITES, a genus of salts formed by of roads, flowering from June to September: the acetous acid.

mixed instead of hops by the inhabitants of ACETOUS acid. See ACETIC Acid. Dalekarlia in their ale, in order to give it an

ACHANIA, in botany, a genus of the inebriating quality: recommended by AnMonadelphia Polyandria class, and the patu derson in his Essays on Agriculture, for culral order of Columniteræ. There are three tivation, though thought to be a noxious species, viz. the A. malvaviscus, scarlet weed in pastures : the bruised herb treśla achania, or bastard hibiscus, which is na- is recommended by Linnæus as an excellent tive of Mexico and Jamaica; cultivated here vulncrary and styptic, and by foreign phyin 1714 by the Duchess of Beaufort, and sicians iu hemorrhages, and thonght by Dr. flowering through the greatest part of the Hill to be excellent in (lysenteries, when adyear: the mollis, or woolly achania, a native ministered in the form of a strong decoction. of South America and the West India islands ; An ointment is made of it for the piles, and found in Jamaica by Houstonn, in 1730, and for the scab in sheep; and an essential oil is 'introduced in 1780 by B. Bewick, Esq. and extracted from the flowers; but it is not Aowering in August and September: and used in the present practice. the pilosa, or hairy achania, a native of Ja. ACHRAS, or SAPOTA-Plum, in botany, maica; introduced in 1780 by Mr. G. Alex a genus of the Hexandria Monogynia class, ander, and flowering in November. Acha- and of the natural order of Dumosæ. There nia is generally propagated by cuttings, are four species, viz. The mammosa, or which are planted in pots of light earth, mamme sapota, otherwise called nippled, S. plunged into a gentle hot-bed, and kept from or American marmelade; growing in Amethe air till they take root, when they should rica to the height of thirty or forty feet, with be gradually inured to the open air. They leaves a foot long, and three inches broad in must be preserved in winter in a moderate the middle, cream-coloured flowers, and large stove; and kept warm in summer, they will oval fiuit, containing a thick, luscious pulp, flower, and sometimes ripen fruit.

called natural marmelade. This tree is ACHERNER, in astronomy, a star of the planted for the fruit in Jamaica, Barbadoes, first magnitude, in the southern extremity of Cuba, and most of the West India islands, the constellation Eridanus. See the article and was cultivated here by Mr. Miller in ERIDANUS.

1739. Of this the is a variety called the ACHILLEA, milfoil, in botany, so called bully, or visberry bully-trec, because it is the from Achilles, who is supposed to have ac tallest of all the trees in the woods : it is esquired some knowledge of botany from his teemed one of the best timber trees in master Chiron; and to have used this plant Jamaica. 2. The sapota, which grows to for the cure of wounds and ulcers; a genus the height of sixty or seventy feet, without of the Syngenesia Polygamia Supersua class knots or branches, and bears a round, yelof plants, and of the natural order of Com- low frnit, bigger than a quince, which smells positæ Discoideæ. There are 27 species, of well, and is of an agreeable taste. It is which the most remarkable are the ptarmi common at Panama, and some other places ca, or sneezewort, M. growing wild in all the in the Spanish West Indies, but not to be temperate parts of Europe, fouud in Britain found in many of the English settlements. not uncommonly in meadows, by the sides It was cultivated here by Mr. Miller in of ditches, on the balks of corn fields, in moist 1739. 3. The dissecta, or cloven-towered woods, and shady places. The shoots are S. cultivated in Malabar for the fruit, put into sallets, and the roots, being hot and which is of the form and size of an olive, biting, are used for the tooth-ache, whence having · pulp of a sweetish acid flavour. Its

SCOPE.

leaves are used for cataplasms to tumours, tallic oxides and earths, and form with them bruised and boiled with the root of curcuma those compounds called in chemistry salts. and the leaves of ginger ; supposed to be a Every acid does not possess all these pronative of the Philippine islands, and proba- perties, but they all possess a sufficient bly growing in China, and found by Forster number to distinguish them from other sub. flowering in September, in the island of stances. See CHEMISTRY. Tonga tabu. 4. The salicifolia, or white wil. ACIDIFIABLE buse, or Radical, any low, S. called in Jamaica the white-bully, substance capable of uniting without detree

, or galimeta wood, which supplies good composition with such a quantity of timber. The bark of the sapota and mam

oxygen as to become possessed of acid mosa is very astringent, and is called cortex properties. Almost all the acids agree with jamaicensis. This was once supposed to be each other in containing oxygen, but they the true Jesuits bark, but its effects on the differ in their bases, which determine the negroes has been pernicious. These trees species of the acid. Sulphur combined with cannot be preserved in England, but with certain portions of oxygen forms su'phurous great care and much heat.

or sulphuric acid, according to the quantity ACHROMATIC, an epithet expressing of oxygen absorbed. a want of colour, introduced into astronomy ACIDOTON, in botany, a genus of the by De la Lande. ACHROMATIC telescopes, are telescopes male and female tlowers on the same, or a

Monoecia Poliandria class and order; it has contrived to remedy the aberrations in co

different tree. There is but one species, lours. They were invented by Mr. Jolin Dolland, optician.

viz. A. urens, a native of Jamaica, which Sec Optics, TELE

grows to the height of eight or nine feet. ACHYRANTHES, in botany, a genus of

ACIPENSER, a genus of fishes of the the Pentandria Monogynia class of plants, that the head is obtuse, the mouth is an

order Cartilagenei: the characters are, belonging to the natural order of Miscellanez. There are eleven species, but they have

der the head, retractile, and without teeth ;

that the four cerri are below the front, but little beauty, and are only preserved in botanic gardens.

and before the mouth; the aperture of the ACHYRONIA, in botany, a genus of the gills is at the side, the body is elongated Diadelphia Decandria class and order, calyx

and angulated with many series of scuta, five-toothed; the lower tooth elongated and

or scaly protuberances. These may be cloven: legume compressed, many-seeded;

ranked among the larger fish; are inhabione species, viz. A. villosa, a shrub found

tants of the sea, but ascend rivers annu. in New Holland, with long silky hairs; ally; the flesh of all of them is delicious ; leaves lanceolate, acute, entire, with silky

from the roe is made caviar, and from hair round the margin.

the sounds and muscular parts is made ACIA, in hotany, a genus of the Mona- isinglass; they feed on worms, and other delphia Dodecandria class and order: calyx fishes: the females are larger than the five-parted, five petals, drupe dry, coria

males. There are tive species: A. sturio, ceous, fibrons, ope-seeded. Two species, Mediterranean, Red, Black, and Caspian

or common sturgeon, inhabits European, trees sixty feet high, found in Guiana. ACICARPHA, in botany, a genus of the

seas, and annually ascends rivers in the Poligamia Necessaria class and order: re

spring. (See plate I. Ichthyology, fig. 2.) A. ceptacle chaffy, the chaff uniting with the schypa, inhabits the Caspian sea, and large seeds after flowering; seeds naked; florets - lakes of Siberia. A. ruthenus, and A. stella

A. hufo, tubular; calyx tive-parted. One species tus, both inhabit the Caspian sea. found in Bnenos Ayres.

inhabits the Danube, Wołga, and other Rus. ACID, in chemistry, a term originally sy

sian rivers, and also the Caspiau. The skin nonymous with sour, and applied only to

of this species is so hard and tough, as to bodies distinguished by that taste; but it be used for carriage traces. See STURGEON. now comprehends under it all substances

ACNIDA, Virginian hemp, in botany possessed of the following properties. Acids,

a genus of the Pentandria Pentagynia class when applied to the tongue, excite the sen

and order. There is but a single species, sation of sour; they change the blue colours

viz. A. cannabina, which is a native of Vir. of vegetables to a red; they unite with wa- ginia, and some other parts of America ; it ter in almost any proportion; they combine is seldom cultivated in Europe. with all the alkalies, and most of the me ACONITUM aconite, wolf's-bane, or

[ocr errors][ocr errors]

monk's-hood, in botany, a genus of plants used for medicinal purposes. The Indians
of the Trigynia order and Polyandria class, are said to use aconite, corrected in cow's
and pertaining to the natural order of Mul- urine, with good success against tevers.
tisilique. In the last edition of Linnæus, by There is one species of it which lias been
Gmelin, this genus comprehends fourteen deemed an antidote to those that are poi-
species; most of the species of aconite have sonous, called anthora, and those that are
been deemed poisonous. The ancients poisonous are called thora. The taste of
were so surprised at their pernicions effects, the root of the species denominated an-
that they were afraid to touch the plants; thora, is sweet, with a mixture of bitter-
and hence sprung many superstitious pre ness and acrimony, and the smell is plea.
cautions about the manner of gathering sant. It purges violently when freshi, but
them. Theophrastus relates that there was loses its qualities when dried. This is poi-
à mode of preparing the aconite in his days, sonous as well as the others, though in
so that it should only destroy at the end of a slighter degree, and is disused in the
one or two years. But some have questioned present practice. The first person who
whether the aconite of Theophrastus, Di ventured to introduce the common monk's-
oscorides, Pliny, and other ancient writers, hood into medicine was Dr. Stoerck.
be the same with ours, or should be refer- Stoerck recommends two grains of the ex-
red to the venus of Ranunculns. It is confi tract to be rubbed into a powder, with
dently afirmed, that the huntsmen on the two drams of sugar, and to begin with ten
Alps, who lunt the wolves, and other wild grains of this powder two or three times
animals, dip their arrows into the juice of a-day. The extract is often given from one
these plants, which renders the wounds grain to ten for a dose; and some bave
occasioned by them mortal. A decoction considerably increased the quantity. In-
of the roots has been used to kill bngs; stead of the extract, a tincture lias been
and the powder disguised in bread, or some made of the dried leaves, macerated in six
other palatable vehicle, has been employed times their weight of spirits of wine, and
to destroy rats and mice. The A. napellus, forty drops given for a dose.
or common monk's-hood, has been long ACORN, an ornamental" piece of wood,
known as one of the most virulent of all vege- . in the shape of a cone, fixed to the top of
table poisons. Linnæus says, that it is fatal to the spindle of a mast-head, above the vane,
swine and goats, but does no injury to horses, to keep it from coming off the spindle.
who eat it dry. He also intorms us, from the ACORUS, in botany, the sweet flag, or
Stockholm Acts, that an ignorant surgeon sweet rush, a genus of the Monogynja or-
died in consequence of taking the fresh leaves, der, and Hexandria class of plants, and be-
which he prescribed to a patient. The ef. longing to the natural order of Piperitæ.
fluvia of the herb in full flower have pro. There are two species, viz. the A. calamus,
duced swooning fits, and a temporary loss of or common sweet rush, of which there are
sight. The caves and shoots of this plant, two varieties, the vulgaris, or European
used as salad, instead of celery, have sweet rush, or calamus aromaticus, and the
proved fatal in several instances. But the Asiaticus or Indian calamus aromaticus.
most powerful part of the plant is the root. The common calamus aromaticus grows
Matthiolus relates, that it was given by naturally on the banks of the rivers, and in
way of experiment to four condemned cri- shallow standing waters; and is found in
minals, tuo at Rome in 1524, and two at many parts of England, but is much more
Prague in 1561, two of whom soon died, plentiful in the standing waters of Holland,
and the other two, with great difficulty, and is common in many other parts of Eu-
were recovered. The juice applied to the rope. The Indian calamlis, which grows
wound of a finger, not only produced pain not only in marsh ditches, but in more ele-
in the arm and hand, but cardialgia, anxiety, vated and dry places, in Malabar, Ceylon,
sense of suffocation, syncope, &c. and the Amboyna, and other parts of the East
wounded part spliacelated before it came to Indies, ditters but little from the European,
suppuration. Dodonæus says, that tive except that it is more tender and narrow,
persons at Antwerp died in consequence of and of a more hot and pungent taste; and A.
eating it by mistake. The effects of this graminers, or Chinese sweet-grass, has the
plant are convulsions, giddiness, insa roots in tufis, with a few thready fibres.
nity, violent evacuations, both upwards The whole herb has an aromatic smell when
and downwards, faintings, cold sweat, and bruised, resembling the English sweet-flag,
even death itself, Nevertheless it has been from which it is distinguished by the short-

1

ness of that portion of its stalk, which is vague view of things. Some followed the above the spadix, as well as by all its parts, opinion of Zeno, without any farther atexcept the florets, being five times smaller tempts to give a distinct conception of the than in that plant. It is probably a native explanation, or to compare it with experiof China, and cultivated for the sake of its ment. But in later times, during the arsmell, in pots near the habitations of the dent researches into the phenomena of Chinese. The sweet flag will succeed very nature, this became an interesting subject well in moist garden ground, but never of inquiry. The invention of the air-pump produces its spikes, unless it grows in wa gave the first opportunity of deciding by ter. The dried roots of the calamus aro. experiment, whether the elastic undulations maticus are commonly imported from the of air were the causes of sound ; and the Levant, thongh those grown in England are trial fully established the point; for a bell equally good. They have a strong aro. rung in vacuo gave ud sound, and one rung matie smell, and a warm pungent taste; in condensed air gave a very loud one. It the flavour is much improved by drying. was therefore received as a doctrine in geThe powdered root might perhaps supply neral physies that air was the vehicle of the place of foreign spices; and indeed it is sound. The celebrated Galileo, the parent the only native aromatic plant of northern of mathematical philosophy, discovered the climates. It is carminative and stomachic, nature of that connection between the and often used as an ingredient in bitter in- lengths of musical chords and the notes fusions.

which they produced, which had been obACOTYLEDONES, in botany, plants served by Pythagoras, or learned by him so called, because their seeds are not fur- in his travels in the East, and which he nised with lobes, and of course put forth made the foundation of a refined and beau. no seminal leaves. All mosses are of this tiful science, the theory of music. Galileo kind. See COTYLEDONES.

shewed, that the real connection subsisted ACOUSTICS, in physics, is that science between the tones and the vibrations of which instructs us in the nature of sound. It these chords, and that their different deis divided by some writers into diacoustics, grees of acuteness corresponded to the difwhich explains the properties of those sounds ferent frequency of their vibrations. The that come distinctly from the sonorous body very elementary and familiar demonstration to the ear; and catacoustics, which treats of which he gave of this connection, did not reflected sounds: but this distinction is not satisfy the curious mathematicians of that vecessary. In the infancy of philosophy, inquisitive age; and the mechanical theory sound was held to be a separate existence; of musical chords was prosecuted to a great it was conceived to be wafted through degree of refinement. In the course of the air to our organs of hearing, which it this investigation, it appeared that the chord was supposed to affect in a manner resem vibrated in a manner precisely similar to a bling that in which our nostrils are affected peudulum vibrating in a cycloid. It mast when they give us the sensation of smell. therefore agitate the air contiguous to it in Yet, even in those early years of science, the same manner: and thus there is a partithere were some, and, in particular, the ce cular kind of agitation that the air can receive lebrated founder of the Stoic school, who and maintain, which is very interesting. held that sound, that is, the cause of sound, Sir Isaac Newton took up this question was only the particular motion of external as worthy of his notice; and endeavoured gross matter, propagated to the ear, and to ascertain with mathematical precision there producing that agitation of the organ the mechanism of this particular class of unby which the soul is immediately affected dulations, and gave us the principal theowith the sensation of sound. Zeno says, rems concerning the undulations of elastic “ Hearing is produced by the air which fluids, which make the 47, &c. Propointervenes between the thing sounding and sitions of Book II. of his Principles of Nathe ear. The air is agitated in a spherical tural Philosophy. They have been consiform, and moves off in waves, and falls on dered as giving the doctrines concerning the ear, in the same manner as water un the propagation of sound. Most sounds, dulates in circles when a stone has been we all know, are conveyed to us by means thrown into it." The ancients were not re of the air. In whatever manner they either markable for precision, either of concep- float upon it, or are propelled forward in tion or argument, in their discussions, and it, certain it is, that, without the vehicle of they were contented with a general and this or some other fluid, we should have no

[ocr errors][ocr errors][ocr errors][ocr errors]

sound will be the most distinctly heard. gested is the most deserving of our atten. The augmentation of sound, by means of tion. He tells ns, that “ the augmentation speaking. trumpets, is usually illastrated in of the sound depends on its reflection from the following manner : Let ABC, tig. 3, be the tremulous sides of the tube ; which the tube, BD the axis, and B the mouth reflections, conspiring in propagating the piece for conveying the voice to the tube. pulses in the same direction, must increase Then it is evident when a person speaks at its intensity.” Newton also seenis to bave B in the trumpet, the whole force of his considered this as the principal cause, in the voice is spent upon the air contained in the scholium of Prop. 50, B. II. Princip. when tube, which will be agitated through its he says, “We hence see wliy sounds are whole length, and, by various reflections so much increased in stentorophonic tubes, from the side of the tube to the axis, the air for every reciprocal motion is, in each realong the middle part of the tube will be turn, increased by the generating cause.” greatly condensed, and its momentum pro. Farther, when we speak in the open air, portionably increased, so that when it comes the effect on the tympanum of a distant auto agitate the air at the orifice of the tube ditor is produced merely by a single pulse. AC, its force will be as much greater than But when we use a tube, all the pulses prowhat it would have been without the tube, pagated from the mouth, except those in as the surface of a sphere, wliose radius is the direction of the axis, strike against the equal to the length of the tube, is greater sides of the tube, and every point of imthan the surface of the segment of such a pulse becoming a new centre, from whence * sphere whose base is the orifice of the tube. the pulses are propagated in all directions, For a person speaking at B, without the a pulse will arrive at the ear from each of tube, will have the force of his voice spent those points. Thus, by the use of a tube, in exciting concentric superficies of air all a greater nunber of pulses are propagated round the point B; and when those super to the ear, and consequently the sound inticies or pulses of air are diffused as far as creased. The continement too of the voice D every way, it is plain the force of the may have a little effect, though not such voice will there be diffused through the as is ascribed to it by some; for the conwhole superficies of a sphere whose radius densed pulses produced by the naked voice is BD; but in the trumpet it will be so con freely expand every way; but in tubes, the fined, that at its exit it will be diffused lateral expansion being diminished, the dithrough so much of that spherical surface rect expansion will be increased, and conof air as corresponds to the orifice of the sequently the velocity of the particles, and tube, But since the force is given, its in the intensity of the sound. The substance tensity will be always inversely as the num also of the tube has its effect; for it is found ber of particles it has to move; and there. by experiment, that the more elastic the fore in the tube it will be to that without, substance of the tube, and consequently the as the superficies of such a sphere to the area more susceptible it is of these treinnlous of the large end of the tube nearly. But motions, the stronger is the sound. If the it is obvious, Dr. M. Young observes, that tube be laid on any non-elastic substance, the confinement of the voice can have little it deadens the sound, because it prevents effect in increasing the strength of the the vibratory motion of the parts. The sound, as this strength depends on the ve sound is increased in speaking-trumpets, if locity with which the particles move. Were the tube be suspended in the air ; because this reasoning conclusive, the voice should the agitations are then carried on without issue through the smallest possible orifice; interruption. These tubes should increase cylindrical tubes would be preferable to any in diameter from the mouth-piece, becanse that increased in diameter ; and the less the the parts vibrating in directions perpendicu. diameter, the greater would be the effect lar to the surface will conspire in impelling of the instrument; because the plate or forward the particles of air, and consemass of air to be moved would, in that quently, by increasing their velocity, will incase, be less, and consequentiy the effect crease the intensity of the sound : and the of the voice the greater; all which is con. surface also increasing, the number of points tradicted by experience. The cause of the of impulse and of new propagation will inincrease of sound in these tubes must there crease proportionally. The several causes, fore be derived from some other principles: therefore, of the increase of sound in these and among these we shall probably find, tubes, Dr. Young concludes to be, 1. The that what the ingenious Kircher has sug. diminution of the lateral, and consequently

« PreviousContinue »