SUPPLEMENT of an arch, in geometry, or trigonometry, is the number of degrees that it wants of being an intire semicircle; as a complement, signifies what an arch wants of being a quadrant.

SUPPORTED, in heraldry, a term applied to the uppermost quarters of a shield when divided into several quarters, these seeming as it were supported or sustained by those below. The chief is said to be supported when it is of two colours, and the upper colour takes up two-thirds of it. In this case it is supported by the colour underneath.

SUPPORTERS, in heraldry, figures in an achievement placed by the side of the shield, and seeming to support or hold up the same. Supporters are chiefly figures of beasts: figures of human creatures, for the like purpose, are properly called tenants. Some make another difference between tenant and supporter: when the shield is borne by a single animal, it is called tenant; when by two, they are called supporters. The figures of things inanimate sometimes placed aside of escutcheons, but not touching or seeming to bear them, though sometimes called supporters, are more properly cotises. The supporters of the British arms are a lion and an unicorn. In England, none under the degree of a banneret are allowed supporters, which are restrained to those called the high nobility. The Germans permit none but princes and noblemen of rank to bear them; but among the French formerly the use of them was more promiscuous.

SUPPRESSION, in grammar and rhetoric, denotes an omission of certain words in a sentence, which yet are necessary to full and perfect construction: as, "I come from my father's;" that is, "from my father's house." Suppression is a figure of speech very frequent in our language, chiefly used for brevity and elegance. Some rules relating thereto are as follow: 1. Whenever a word comes to be repeated in a sentence oftener than once, it is to be suppressed. Thus we say, "This is my master's horse," not " This horse is my

master's horse." 2. Words that are necessarily supplied may be suppressed: and, 3. All words that use and custom suppress in other languages, are also to be suppressed in English, unless there be particular reasons for the contrary.

Suppression is also a figure in speech whereby a person in rage, or other disturb. ance of mind, speaks not out all he means,

but suddenly breaks off his discourse. Thus the gentleman in Terence, extremely incensed against his adversary, accosts him with this abrupt saying, "Thou of all.” The excess of his indignation and rage choaked the passage of his voice, and would not suffer him to utter the rest. But in these cases, though the discourse is not complete, the meaning is readily understood, and the evidence of the thought easily supplies the defect of words. Suppression sometimes proceeds from modesty and fear of uttering any word of ill and offensive sound.

SURD, in arithmetic and algebra, denotes any number or quantity that is incommensurable to unity: otherwise called an irrational number or quantity.

The square roots of all numbers, except 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, &c. (which are the squares of the integer numbers, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, &c.) are incommensurables: and after the same manner the cube roots of all numbers but of the cubes of 1, 2, 3, 4, 5, 6, &c. are incommensurables: and quantities that are to one another in the proportion of such numbers, must also have their square-roots, or cube roots, incommensurable.

The roots, therefore, of such numbers, being incommensurable, are expressed by placing the proper radical sign over them: thus 2, 3, 5, 6, &c. express numbers incommensurable with unity. However, though these numbers are incommensurable themselves with unity, yet they are commensurable in power with it; because their powers are integers, that is, multiples of unity. They may also be commensurable sometimes with one another, as the 8 and

2; because they are to one another as 2 to 1: and when they have a common measure, as 2 is the common measure of both; then their ratio is reduced to an expression in the least terms, as that of commensurable quantities, by dividing them by their greatest common measure. This common measure is found as in commensurable

quantities, only the root of the common

measure is to be made their common divi√12 ✓ 18 a sor: thus = √4=2, and 2

=5=125. Or you need only, in involving surds, raise the quantity under the radical sign to the power required, continuing the same radical sign; unless the index of that power is equal to the name of the surd, or a multiple of it, and in that case the power of the surd becomes rational. Evolution is performed by dividing the fraction, which is the exponent of the surd, by the name of the root required. Thus, the square root of a' is a orā3.

The surdu xax; and, in like manner, if a power of any quantity of the same name with the surd divides the quantity under the radical sign without a remainder, as here a" divides a x, and 25 the square of 5, divides 75 the quantity under the sign in 75 without a remainder; then place the root of that power rationally before the sign, and the quotient under the sign, and thus the surd will be reduced to a more simple expression. Thus, 755/ 3; 2/ 48 2/3 × 16

4S;8127 × 3 = 33. When surds are reduced to their least expressions, if they have the same irrational part, they are added or subtracted, by adding or subtracting their rational coefficients, and prefixing the sum or difference to the common irrational part. Thus, 75+ 48 = 5 √ 3 + 4 √√ 3 93; 81+24=3√3+2 353; 150-545 N 6—3√6=2✓ 6; √ a x + √ π x = a √ x + b √ x = a + b × √x.

Compound surds are such as consist of two or more joined together; the simple

This operation is of use in reducing surd expressions to more simple forms. Thus, suppose a binomial surd divided by another, as 2012, by 5—3, the quotient might be expressed by ✓ 20+✓ 12 But this might be expressed in a more simple form, by multiplying both numerator and denominator, by that surd, which, multiplied into the denominator, gives a rational product: thus, ✔20+✓12√20+✓ 12 √5+vs. X √5-√3 √5-√3 √/100+2√60+6_ 16+2 √ 60 5-3

2 15.

=

=

When the square root of a surd is required, it may be found, nearly, by extracting the root of a rational quantity that approximates to its value. Thus, to find the square root of 3+2 2, first calculate

√ 2 = 1,41421. Hence 3+2 √ 2 = 5,82842, the root of which is found to be nearly 2,41421.

In like manner we may proceed with any other proposed root. And if the index of the root, proposed to be extracted, be great, a table of logarithms may be used. Thus, 5+17 may be most conveniently found by logarithms.

Take the logarithms of 17, divide it by 13; find the number corresponding to the quotient; add this number to 5: find the logarithm of the sum, and divide it by 7, and the number corresponding to this quotient

will be nearly equal to 5+ 17.

But it is sometimes requisite to express the roots of surds exactly by other surds. Thus, in the first example, the square root of 3+22 is 1+2: for 1+2x 1+√2=1+2√2 + 2 = 3 + 2 √2.

For the method of performing this, the curious may consult Mr. Maclaurin's Algebra.

SURETY of the peace. A justice of the peace may, according to his discretion, bind all those to keep the peace who, in his presence, shall make any affray, or shall threaten to kill or beat any person, or shall contend together in hot words; and all those who shall go about with unlawful weapons, or attendance to the terror of the people; and all such persons as shall be known by him to be common barrators; and all who shall be brought before him by a consta ble, for a breach of the peace in the presence of such constable; and all such persons who having been before bound to keep the peace, shall be convicted of having forfeited their recognizance. When surety of the peace is granted by the Court of King's Bench, if a supersedeas come from the Court of Chancery to the justices of that court, their power is at an end, and the party as to them discharged.

If surety of the peace be desired against a peer, the safest way is to apply to the Court of Chancery or King's Bench. If the person against whom security of the peace be demanded be present, the justice of the peace may commit him immediately, unless he offer sureties; and à fortiori he may be commanded to find sureties, and be committed for not doing it.

SURGERY is that division of the healing art, which is chiefly conversant with the treatment of the external and local disorders of the body, of the effects of accidental injury, and of such diseases in general as are curable by manual operation. Yet its field is not entirely confined to the department just alluded to; since local disorders, and particularly accidents, often affect the whole frame, so as to induce a general derangement of the constitution; and again, diseases of parts arise out of constitutional affectious, or, although originally inde. pendent, may be greatly aggravated by them. Hence it is obviously necessary that the surgeon should be acquainted with the nature and treatment of such general disorders; and consequently, in marking out the limits, which divide the departments of the surgeon and physician, it is hardly possi prevent all supposed encroachment of ei ble to attain such a pitch of accuracy as to ther side on the province of the other.

The care of the external and local affections of the human body was, in the infancy of science, a branch of the art of medicine.

Surgery and physic were then, and for many ages afterwards, practised by the same individuals. These, however, in course of time, began to consider the manual and operative part of the profession as too mechanical and low for persons of their scientific education, and consequently resigned them to an inferior class of uneducated men, who generally combined with them the trade of the barber. Hence arose in most countries of Europe the calling of barber-surgeon; which included, besides shaying, hair-dressing, &c. tooth-drawing, bleeding, dressing of ulcers, and other of the more common and easy parts of operative surgery. While contaminated by so degrading an alliance, and practised by persons wholly illiterate, we cannot be sur prised to find that surgery and its professors met with neglect and contempt, and that the latter were considered as merely subordinate to the physicians. The barbersurgeons must still have had opportunities of seeing and learning disease; they began to get an insight into the structure of the human body; and they acquired a respec tability by being employed in wars in the cure of the wounded. The physicians, who were still the only regularly educated and scientific class of men practising the art of healing, wished to retain their old and long enjoyed superiority; and hence arose in many countries long and sharp disputes with the barber surgeons, which ended at last, as the progress of civilization and improvement would naturally lead us to expect, in the separation of the barbers and surgeons, and the elevation of the latter to their proper rank and consideration in society.

Whatever part of the subject we may contemplate, we shall find that the art of surgery requires, no less than that of physic, all the advantages that can be derived from the most liberal education; that it demands still more imperiously a familiar knowledge of anatomy and physiology, i. e. of the structure and functions of that machine, whose derangements it proposes to remedy; and consequently, that although prejudice still assigns to the physician a su perior rank to that of the surgeon, they must be considered in modern days, as equals, whether we regard the reason of the thing, or proceed to an actual comparison of individuals.

Our opinions concerning the education and qualifications of the surgeon will be easily collected from the foregoing observations. Instead of spending seven years of VOL. VI.

the most valuable part of his life in the drudgery of an apothecary's shop, the youth destined for the profession of surgery should receive a learned and liberal education. The Latin language among the dead, and the French of the living, are indispensibly necessary; and the German would form a very useful addition to these."

Anatomy and physiology are the next objects of attention, and demand the most assiduous cultivation; these sciences are the foundation on which the art of surgery rests. The study of chemistry and natu ral philosophy will be pursued at the same time. When prepared by these previous steps, the student may commence the practical part of his education in the large hospitals of the metropolis; carefully studying diseases themselves, taking notes of the most interesting cases, and omitting no opportunity of observing the alterations occasioned by disease in the structure of the body. Lectures on surgery, on the materia medica, and the practice of medicine must also be attended. The performance of surgical operations on the dead body will be highly beneficial, as leading to the study of those parts of anatomy, which are more particularly concerned in operations, and as imparting the manual skill necessary to the operator.

Of systematic works on surgery there is none, which unites the recommendations of clearness, shortness, and comprehension, to so great a degree, as the "First Lines of the Practice of Surgery," by Mr. S. Cooper, to which we therefore refer the reader The larger systems are by no means unexcep tionable; we may mention that of Latta ; the "Systema Chirurgiæ hodierna" of Callisen; and the "Anfangs-gründe der Wundarzney kunst" of Richter. Generally, however, the works that treat of particular subjects are to be preferred to the systems of surgery. The writings of Mr. Pott, and the "Memoirs of the French Royal Academy of Surgery," contain a great deal of valuable information; as also do those of John Hunter, Home, Abernethy, and Astley Cooper; Le Dran, Sharp, Bertrandi, and Sabatier, may be read on the operations. The numerous other sources of surgical knowledge will be discovered by the student in his progress. The following sketch will be divided into general surgical subjects, or such disorders as are common to several situations in the body, including also the constitutional derangements which accompany or cause local disorders; and

U