II E T 



RET 



the anatomical word retina, applied to the nervous network 

 of the eye. This genus was founded, by the above author, 

 on a fruit given him by profeffor Hermann, and faid to be- 

 long to a climbing fhrub of the Mauritius. So nearly do 

 Gaertner's plate and defcription approach to the fruit of 

 Gouania domingenfu, that we have no doubt of their be- 

 longing to fome fpecies of the fame genus ; probably to one 

 that we have defenbed in our article GouANIA, though, 

 pofleffing none but the domlngenfu in fruit, we cannot exactly 

 appropriate Gartner's fynonym. He lcems not to have 

 been acquainted with the fruit of a Gouania. 



RETINAS PH A LTUM, in Mineralegy, a name given 

 to an inflammable kind of refinous fubftance, accompanying 

 Bovey coal. It has a pale brown ochre-yellow colour, is 

 very brittle, and breaks with a vitreous fratture. Its fpe- 

 citic gravity is 1.135. When held in the hand for fome time, 

 it emits a (lightly refinous fmell, but when burned it has a 

 fragrant odour ; at lail the fmell is bituminous. On the firft 

 application of heat it melts and fmokes, and then burns 

 with a bright flame. When the melted mafs is cooled, it is 

 black and brittle, and breaks with a glaffy frafture. It is 

 not afted on by water, but is partly diffolved by alcohol, 

 potafh, and nitric acid ; the diffolved portions having the 

 properties of a refin ; the undiffolved of afphaltum. It was 

 analyfed by Mr. Hatchett, and is compofed of 

 55 Refin, 

 41 Afphaltum, 

 3 Earths. 



A fimilar fubftance occurs in the wood coal at Cologne, 

 and was alfo recently difcovered in making the excavation for 

 the Tunnel at Highgatre. It may be doubted, however, 

 whether thefe fubilances are more entitled to be ranked 

 among minerals than the other vegetable matters found in 

 alluvial ground. 



RETINUE, Retinentia, the attendants or followers 

 of a prince, or perfon of quality, chiefly in a journey. 



In Laiv, thofe perfons are properly faid to be of a noble- 

 man's retinue, who belong to him in quality either of fer- 

 vants or retainers. 



RETIRADE, in Fortification, a kind of retrenchment 

 made in the body of a bailion, or other work, which is to 

 be difputed inch by inch, after the firft defences are dif- 

 mantled. It ufually confifts of two faces, which make a 

 re-entering angle. When a breach is made in a baftion, the 

 enemy may alto make a retirade, or a new fortification be- 

 hind it. 



RETIRED Flank. See Flank. 



Retired Lift, a lift on the marine eftablifliment, on 

 which fuperannuated officers are placed. 



In the Eaft India fervice, the company have refolved that 

 a military officer, after 20 years' aftual fervice in India, 

 who comes to Europe upon leave, may be allowed to retire 

 on the pay of his rank, .provided he fignifies his intention of 

 fo doing, within 20 months after his arrival. Officers on 

 leave who are defirousof retiring, and who declare their in- 

 tention to that effeft, within 12 months from their arrival, 

 will be permitted to retire on the pay of the rank to which 

 they may be intitled at that period. An officer having com- 

 pleted 22 years' refidence in India will be allowed to retire 

 on the full pay of his rank, direftly on his leaving India. 



RETMANDORF, or Radoyelza, in Geography, a 

 town of the duchy ot Carniola, on the Save ; 52 miles W. 

 ef Cilley. N. lat. 46 22'. E. long. 14 5', 



RETONVILLER, a town of France, in the department 

 of theSomme; four miles N.E. of Roye. 



RETORBIO, a town of Italy, in the Pavefe ; 14 miles 

 S. of Pavia, 



RETORNO Falfo Brevium, in Law. See Falso. 



Retorno Habendo, &c. See Returxo habendo, and Re- 

 plevin. 



RETORT, Retorta, in Chemiftry, a kind of crooked 

 matrafs, or a round bellied veffel, made of earth, glafs, or 

 metal, with a flender crooked beak or neck, to which the 

 recipient is to be fattened. 



From this form this veffel has been probably called a re- 

 tort. The moll capacious part is called the belly ; its upper 

 part the arch or roof of the retort ; and the bent part, 

 which makes with the belly an angle of about fixty degrees, 

 is the neck ; and the paflage from the belly to the neck 

 fhould be free and wide, and gradually diminifhing to the 

 extremity of the neck or mouth of the retort. Retorts 

 differ in form and materials; their bellies are generally round; 

 fome of them are oblong, and fhaped like a cucurbit, and 

 thefe are called Englifh retorts. They are preferable for the 

 diilillation of matters which are fubject to fwell, and to pafs 

 into the receiver before they be decompofed. 



A retort, which has a little hole pierced in its roof, is 

 called a tubulated retort. This hole muft be capable of 

 being exactly clofed with a ftopper of proper materials. 

 Retorts of this kind are employed in diftillations, where 

 fome matter muft be introduced into the retort after the 

 receiver is joined to it, as in the diilillation of fmoking 

 marine acid, and in the operations for procuring the feveral 

 kinds of clyflus. 



When the retort is of glafs, it is ufually covered with a 

 lute of loam, Sec. an inch thick, to enable it to bear the 

 fire the better ; and it is ufed for all operations which re- 

 quire a lefs heat than is fufneient for its fufion. Earthen 

 retorts are neceflary when great heat is requifite, as in the 

 preparation of phofphorus. 



The retort feems to draw fpirits and oil from woods, 

 gums, minerals, earths, and other matters which require a 

 llrong fire. 



The retort is a kind of compendium or improvement or* 

 the cucurbit and bolt-head ; anfwering all the purpofes of 

 both, without the affiftance of a capital or head, which 

 the other require. 



The quantity of air arifing from fome fubilances is apt 

 to burll glades in diftilling ; Dr. Browne Langrifh has, 

 therefore, given us a new contrivance of applying receivers 

 to retorts, by which fuch accidents may be prevented. To 

 his firft receiver he adapts a fecond, inferted into an opening 

 at the top of the firft, in order to give more room to the 

 rarefied and new generated air. To an opening at the 

 bottom of each of thefe receivers, he fixes a bottle, tied on 

 clofe by means of a bladder, fo that they may be removed 

 at any time, and another inftantly placed in their room ; by 

 which means very little of the iteam will efcape. He alfo 

 ties on a bladder to an opening, or upper neck of the fecond 

 recipient ; and this bladder being much thinner and weaker 

 than any of the glafles, will always give way firll, and pre- 

 vent their burlling. And even when there is the greatell 

 danger of this accident, the fmalleft pin-hole made through 

 the top of the bladder, as foon as the fumes begin to rife, 

 will be fufficient to let out the air as fall as it is generated. 

 See Philof. Tranfaft. N° 475. feft. 3. where we have a 

 figure of the whole apparatus. For a farther account of 

 the retort, and the ufes to which it is applied ; fee Distil- 

 lation and Laboratory. 



RETORTION, in Political Economy. When a fovereign 

 is not fatisfied with the manner in which his fubjedls are 

 treated by the laws and cuftoms of another nation, he is at 

 liberty to declare, that he will treat the fubjefts of that 

 nation in the fame manner as his are treated. This is what 



