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GASSENDI, (PETER,) in biography, a very eminent philosopher and mathematician, and one of the most illustrious ornaments of France, in the seventeenth century, was born in the year 1592, at Chanterseir, about three miles from Digne, in Provence. He afforded early evidence that he possessed a lively and inquisitive genius, and a happy memory, which determined his parents, though they were but in moderate circumstances, to bestow upon him the best education in their power. When he was only four years of age, in consequence of the pious impressions which had been made on his mind, he was accustomed to act the preacher among his playmates; and soon afterwards he began to discover his taste for astronomy, by taking delight in gazing at the moon and stars, when the atmosphere was unclouded. The pleasure which he took in contemplating the heavens often led him to retire to unfrequented spots, where he might feast his eyes without being disturbed; by which means his parents were frequently obliged to seek for him, under anxiety and apprehensions for his safety. When he was of a proper age to be sent to school, he was placed under the instructions of an excellent master at Digne, where he made a rapid progress in the knowledge of the Latin tongue, and also acquired a pre-eminence over his school-fellows in rhetorical exercises. Afterwards he was sent to study philosophy for two years, under an able professor at Aix; and at the expiration of that period returned to his father’s house at Chantersier. He had not been long at home, however, before he was invited to teach rhetoric at Digne, when not quite sixteen years of age; and about three years afterwards he was appointed to fill the vacant chair of philosophy in the University of Aix. During his residence at Digne, he had sedulously prosecuted his studies in the learned languages, mathematics, and astronomy, and after a diligent examination of the different systems of philosophy among the ancients, embraced that of Epicurus, of which he afterwards proved himself the most ingenious defender in modern times. When he entered upon his philosophical professorship at Aix, notwithstanding that the authority of Aristotle was still acknowledged in almost all the public schools, Gassendi, after the examples of Vives, Ramus, and others, ventured publicly to expose the defects of his system. WOL. W.

The lectures which contained his censures of the Aristotelian philosophy, delivered in the indirect form of paradoxical problems, were published under the title of “Exercitationes Paradoxicat adversus Aristotelem.” This work, which gave great offence to those who still retained their predilection for scholastic subtlety, obtained the author no small degree of reputation with several learned men, particularly with Nicholas Peiresc, the president of the University at Aix, who determined to procure for him a situation in the church, in which he should be enabled to pursue his favourite studies at his leisure, and without any molestation. After Gassendi had entered into holy orders, through the interest of Peiresc, and Joseph Walter, prior of Vallette, he was promoted to a canonry in the cathedral church of Digne, and admitted to the degree of doctor of divinity; and afterwards received the appointment of warden, or rector of the same church. In consequence of these promotions, he resigned his professorship at Aix, and retiring to Digne, #. ed himself closely to his philosophical and astronomical pursuits.

Among his other works which he wrote in this place, was a second book of his “Exercitationes Paradoxicae,” intended to expose the futility of the Aristotelian logic. It was his first intention to pursue the plan still further; but the violent opposition which he met with from some of the zealous and powerful advocates for the authority of Aristotle, induced him to desist from all direct attacks upon his philosophy. Still, however, he professed his attachment to the system of Epicurus, and defended it with great learning and ability.

From Lucretius, Laertius, and other ancient writers, he undertook to frame a consistent scheme of Epicurean doctrine, in which the phenomena of nature are immediately derived from the notion of primary atoms. But he was aware of the fundamental defect of this system, and added to it the important doctrine of a divine superintending mind, from whom he conceived the first motion and subsequent arrangement to have been derived, and whom he regarded as the wise governor of the world. He strenuously maintained the atomic doctrine, in opposition to the fictions of the Cartesian philosophy, which were at that time obtaining great credit; and particularly asserted, in opposition to Des Cartes, the doctrine of

P p

a vacuum. On the subject of morals, he

explained the permanent pleasure or in

dolence of Epicurus, in a manner per

fectly consistent with the purest precepts

of virtue. In the year 1628, Gassendi,

for the sake of extending his acquaintance

with the learned, visited Holland, where

his philosophical and literary merit soon

W. him many admirers and friends.

hile he was in that country he wrote

an elegant and judicious apology for his friend, the learned Mersenne, in reply to

the censures of Robert Fludd, on the

subject of the Mosaic philosophy. After his return to France, he continued his philosophical, and particularly his astronomical studies, pursuing, with great care, a series of celestial observations, in order to complete his system of the heavens. Being called by a law-suit to Paris, he there formed an acquaintance with the men most distinguished for science and learning in that capital, and by his agreeable manners, as well as reputation, secured the esteem of persons of high rank and quality, and in particular of Cardinal Richelieu, and of his brother the Cardinal of Lyons. Owing to the application and interest of the latter, in the year 1645, Gassendi was appointed regius-professor of the mathematics at Paris. This institution being chiefly intended for astronomy, our author read lectures on that science to crowded auditories, by which he acquired great popularity, and rose to high expectations.— But the fatigues of that appointment were more than his strength, already reduced by too intense application, was able to bear; and having caught a cold, which brought an inflammation upon his lungs, he was obliged, in the year 1647, to quit Paris, and to return to Digne for the benefit of his native air. After having his health in some measure re-established by the intermission of his studies, in the year 1653 he returned again to Paris, where he published the lives of Tycho Brahe, Copernicus, Purbach, and Regiomontanus; and then resumed, with as much intenseness as ever, his astronomical labours. His feeble state of health, however, was now unequal to such exertions, which brought on a return of his disorder: under which, with the aid of too copious and numerous bleedings, he sunk in 1655, when in the sixty-third year of his age. A little before he expired, he desired his secretary to lay his hand upon the region of his heart; which when he had done, and remarked on the feeble state of its pulsation, Gassendi said to

him, “You see how frail is the life of man o’’ which were the last words he uttered. He is ranked by Barrow among the most eminent mathematicians of the age, and mentioned with Galileo, Gilbert, and Des Cartes. His commentary upon the tenth book of Diogenes Laertius affords sufficient proof of his profound erudition, and his deep skill in the languages. We have already mentioned his opposition to the philosophy of Des Cartes, by which he divided with that great man the o: of his time, almost all of whom were either Cartesians or Gassendists. At one time a coolness took place between those two eminent characters, in consequence of irritating expressions which had escaped from both their pens, during the course of their philosophical warfare. The Abbé d’Estrees, af. terwards Cardinal, with the design of bringing about a reconciliation between them, invited them both to dinner, in company with many of their common friends, among whom were father Mersenne, Roberval, the Abbé de Marolles, &c. At the time fixed, all the expected guests made their appearance, excepting Gassendi, who, during the preceding night, had been attacked by a severe complaint, which prevented him from venturing abroad. As the cause of his absence was explained after dinner, the Abbé d’Estrees carried his whole company along with him to Gassendi's apartments, where they had the pleasure of hearing the two philosophers make mutual acknowledgments of their improper warmth and irritability, and generously declaring, that whatever difference in opinion might afterwards subsist between them, it should produce no unfavourable effect upon their friendship. Gassendi was the first person who observed the transit of Mercury over the sun. Kepler had predicted that it would take place on the 7th of November, 1631. Gassendi, who was then at Paris, made due preparations to observe it, and after having for some time mistaken the appearance of that planet for a solar spot, became at length sensible of his error by the rapidity of its movement; and took care to calculate the time of its egress from the sun’s disk, as well as its distance from the sun's vertical point. From Gassendi's letters, it appears that he was often consulted by the most celebrated astronomers of his time, as Kepler, Longomontanus, Snell, Hevelius, Galileo, Kircher, Bulliald, and others ,

and his labours certainly entitle him to a high rank among the founders of the reformed philosophy. , Gassendi possessed a large and valuable library, to which he added an astronomical and philosophical apparatus, which, on account of their accuracy and worth, were purchased by the Emperor Ferdinand III. and afterwards deposited, with other choice collections, in the Imperial Library at Vienna. The MSS. which he left behind him, and the treatises formerly published by himself, were printed together, accompanied by the author's life, and published by Sorbiere, in six volumes folio, 1658– They consist of the philosophy of Epicurus ; the author's own philosophy; astronomical works; the lives of Periesc, Epicurus, Copernicus, Tycho Brahe, Purbeck, Regiomontanus, John Muller, &c. a refutation of the meditations of Des Cartes; and epistles, and other treatises. GASTEROSTEUS, the stickle-back, in natural history, a genus of fishes of the order Thoracici. Generic character: body carinate on each side, somewhat lengthened, and covered with bony plates; dorsal fin single, with distinct spines between it and the head ; ventral fins behind the pectoral, but above the sternum. There are thirteen species. G. aculeatus, or three spined stickle-back, is found in almost all the fresh waters of Europe, and is about three inches long, and in the beginning of the summer displays the most beautiful combination of bright-red, fine olive green, and silvery whiteness. It is extremely active and rapid, and is particularly injurious in fish ponds, as it devours the spawn of the fish. It is highly voracious, and is reported to have swallowed in the space of five hours, seventyfour young dace, about a quarter of an inch in length. In the fens of Lincolnshire, these fishes appear in immense numbers, and have been frequently sold at the rate of a halfpenny per bushel. They have been often most successfully applied as manure for land. GASTRIC juice, a fluid of the utmost importance in the process of digestion. It does not act indiscriminately on all substances, nor is it the same in all animals, nor does it continue always of the same nature, even in the same animal ; it changes according to circumstances. No certain facts have yet been established as to the nature of the gastric juice: it is however completely ascertained, that it acts with a chemical energy in dissolving food : it attacks the surfaces of bodies,

unites to the particles of them, which it carries off, and cannot be separated from them by filtration. It operates with more energy and rapidity the more the food is divided, and its action is increased by a warm temperature. The food is not merely reduced to very minute parts; its taste and smell are quite changed; its sensible properties are destroyed, and it acquires new and very different ones. This fluid does not act as a ferment, it is a powerful antiseptic, and even restores flesh already putriefied. Two things are well known with respect to the substances contained in the stomach. 1. They contain phosphoric acid; and 2. they have the power of coagulating milk, and the serum in the blood. What the coagulating substance is, has not been discovered, but it is supposed to be not very soluble in water, since the inside of a calf's stomach, after being steeped in water six hours, and then well washed, still furnishes a liquor, on infusion, which coagulates milk. GASTROBRANCHUS, in natural his. tory, a genus of fishes, of the order Cartilaginei. Generic character: mouth beneath, furnished with pectinal teeth, in a double row on each side : body eelshaped, carinate beneath by a soft fin, two ventral spiracles. G. caecus, or the hag-fish, is about five inches in length, in the European seas, but, in those of India, attains the length of a common eel. Its appearance is very similar to that of the lamprey. It is characterized by the circumstance of exhibiting no traces of the existence of such an organ as the eye. It is reported by naturalists, that the hag-fish will often enter the mouths of fishes fixed on the hook of the angler, and gnaw a passage through their bodies, devouring all but the bones and skin. Its substance is so highly glutinous, that a large vessel of sea water

will, in a short time after the living coecus

is placed in it, become of the consistence of jelly. GATE, in architecture, a large door, leading, or giving entrance into, a city, town, castle, palace, or other considerable building : or a place giving passage to persons, horses, coaches, or wagons, &c. GAVELKIND, a tenure or custom belonging to lands in the county of Kent, by which the lands of the father are, at his death, equally divided among all his sons; or the land of a deceased brother, in case he leaves no issue, al...ong all the brethren. This is by some calleti

ancient soccage-tenure: the custom came from our Saxon ancestors, among whom the inheritance of lands did not descend to the eldest, but to all the sons alike : and the reason why it was retained in Kent is, because the Kentish men were not conquered by the Normans in the time of William I. The particular customs attending this tenure are, that the heir, at the age of fifteen, may give or sell his lands in gavelkind; and though the father is attainted of treason and felony, and suffers death, the son shall inherit. A wife shall be endowed of a moiety of the avelkind-lands of which her husband ied seised, during her widowhood. Likewise a husband may be tenant by courtesy of half his wife's lands, without having any issue by her; but if he marries again, not having issue, he forfeits his tenancy. GAUGE-POINT, of a solid measure, the diameter of a circle, whose area is equal to the solid content of the same measure. Thus, the solidity of a winegallon being 231 cubic inches, if you conceive a circle to contain so many inches, the diameter of it will be 17.15; and that will be the gauge-point of wine-measure. And an ale-gallon, containing 282 cubic inches, by the same rule, the gauge-point for ale measure will be found to be 19.15. After the same manner may the gaugepoint of any foreign measure be obtained; and from hence may be drawn this consequence, that when the diameter of a cylinder, in inches, is equal to the gauge-point of any measure, given likewise in inches, every inch in length thereof will contain an integer of the same measure, e. gr. in a cylinder whose diameter is 17.15 inches, every inch in height contains one entire gallon in wine measure ; and in another, whose diameter is 18.95 inches, every inch in length contains one ale gallon. GAUGER, a king's officer, who is appointed to examine all tuns, pipes, hogsheads, and barrels, of wine, beer, ale, oil, honey, &c. and give them a mark of allowance, before they are sold in any place within the extent of his of. fice. GAUGING, is the art of ascertaining the contents of casks, vats, and other regularly formed vessels, either in wine measure, which has 231 cubic inches to the gallon; in ale measure, which has 282 to the gallon; or in corn measure, which has 2150.42 cubic inches to the bushel. To find the contents of a vessel of a rec

tilinear form, you must ascertain the number of square inches on its surface, which being divided by the foregoing numbers (according as you use wine, ale, or corn measure,) will give the contents in gallons. But in this we suppose the vessel to be only one inch in depth ; if more, the number of inches from the surface to the bottom must become a second agent in the calculation. Thus, ifa cooler be a parallelogram of 250 inches long, and 84.5 broad, these measurements being multiplied together, will give an area of 21.125 inches, which being divided by 282, the number of inches in an ale gallon, the result will be 74.9 gallons: or if the product had been divided by .003546, the quotient would have been 74.90925, which is much the same. We have in this case supposed the area to have perpendicular sides, only one inch in depth. If the sides be six inches deep, the foregoing result, viz. 74.9, should be multiplied by 6; which would then give 449.4 gallons to be the measurement of the cooler. Where the sides shelve in, as in most tubs, or project out as in bell casks, regularly increasing or decreasing from the top to the bottom, the whole length at top and the whole length at bottom must be added together, and be halved, so as to give the medium length; and the same to find a medium of the two breadths at top and bottom. These mediums being multiplied together will give an area, which, being multiplied by the depth in inches, will shew the true contents, in either wine, ale, or corn measure, according to the divisor used. When the bottom shelves equally, the measurement at the centre will be a true medium; but if the bottom is uneven and irregular, you must take various measurements in different parts; then add the whole together, and divide by the number of measure. ments, or dips, and the quotient will, in general, be a fair medium. If the vessel is triangular, pentagonal, or anywise polyangular, the area must be ascertained by the ordinary rules in GeoMETRY, which See.

In circular vessels you must multiply the square of the diameter by .002785 for ale, or .003399 for wine: divide the former measure by 359,05, the latter by 294.12, and the quotients will be ale or wine gallons respectively.

Where you have an oval vessel to measure, ascertain the transverse or longest diameter, and the cojugate, or shortest diameter; multiply them together and divide as above.

Prismatic vessels are measured according to the first explanation, and frustrated or pyramidical vessels are disposed of in the same manner as those whose side or sides regularly augment, or vice versa. Truncated cones, likewise, come under the same rule; only treating their terminations as circles, instead of computing them as squares, or rectilinear bases. The following very easy mode of ascertaining the contents of a conic frustum is given by the ingenious Newton. Multiply each diameter (i.e. of top and bottom) by itself; then the one by the other, and the aggregate of those products by the altitude; multiply also the last product by 78539, (the superficial content of a circle whose diameter is 1000); a third art of the product is the measure of the rusturn.

Therefore, when vessels have their sides composed of straight ribs, proceeding in right lines from one to the other end of the conic frustum, the measurement is easily made; thus we may, with: out difficulty, ascertain the contents of great coppers, mashing-tubs, corn-binns, and a great variety of similar vessels. But we rarely see casks of any description formed by the union of two frustrated cones; their usual shape is more spheroidal; that is, they have an arched or swelling course from the bung to the chimb or end ; consequently these contain more than such as are truly conical. This occasions the necessity for allowing something for the bulge or swell, and of taking the diameter at the centre, between the bung and the chimb, which diameter will give a true medium. The thickness of the cask may easily be ascertained by aid of calibre compasses applied to the proper part. The length of the cask may be measured internally, by putting a rod or wand in at the tap hole, and the internal diameter may be taken in a similal way at the bung; but such can only be done when the cask is empty, or, at least, opened for the purpose ; whereas casks that are filled and sealed must often be measured ; for this purpose the calibre compasses are extremely useful, since they embrace the outside measure. To correct the computation, we must usually allow an inch and a half in the whole length, and the same in the whole diameters at the bung and chimb, thus exteriorly taken, for the thickness of the cask itself. This deduction being made, we must compute according to the form or swell of the staves. If they be much raised, we multiply the difference between the diameter at the

bung, and at the end, by .7; if less raised, or swelling, we multiply the difference by .65; if nearly straight, by 6, and if rectilinear, or truly conical, by .55; the product added to the diameter at the end, or head, will give a mean diameter. Suppose the diameter within the bung to be 32 inches, at the head 24, and that the length within be 40; the difference between 32 and 24 is 8, which, multiplied by 7, gives 5.6; add therete the diameter at the head, 24, and the medium will be 29.6; multiply by the length 40, and divide by 359.05, and the quotient will be ale gallons 97.4. And thus, with the other multipliers, according to the apparent bulge or swell between the bung and the chimb, and according to wine or ale measure.

To find the ullage, or quantity of liquor deficient in a cask, we have the following rule. Take the diameter at the bung, and ascertain the number of inches and parts that are dry; say that of 29 inches i3 be dry; also that the whole cask measures 80 gallons. Divide the dry inches 13 by 29, the bung diameter; the quotient will be .148; find the two first figures, 44 under W. S. in the annexed table, and its sequent will be .4238, to which add a proportional part for the 8, and the whole sequent will be 4343, which, multiplied by the contents of the cask, will shew a deficiency of 34.664 gallons. This measurement, however, applies to cylinders only ; if the cask be conical, you must find the mean diameter, which should be deducted from that at the bung; and noting half the difference, which is to be deducted from the wet inches, and reserved. Then, as the mean diameter is to 100, so is the reserved difference to a versed line in the table : and if the segment (to be found in the table, be multiplied, as before shown, into the contents, the product will be the quantity of liquor in the cask.

Example. Let the bung-diameter be 32, the mean-diameter 29.6, and the whole measure 97.4 gallons : say there be 19 inches wet :

From 32.0 From 90 deduct 29.6 take 1.2 remain 2.4 remain 17.8 reserved.

its half is 1.2

Now as 29.6 is to 100, so is 17.8 to .60, the versed sine. The segment to 60 is .6265; which, multiplied by 97.4, the whole contents, the product gives 61 gallons of liquor remaining. By working upon the dry inches, you would have found the ullage, or deficiency.

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