Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/687

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we have fome general theorems for the exterminating unknown quantities in given equations.

EXTERNUS (Cycl. ) — Externus Duverni, a name given by Douglafs to one of the mufcles of the ear, called by Cow- per and others obliquus auris, and by Albinus Externus mallei.

Externus Mallei, in anatomy, a name given by Albinus to one of the mufcles of the ear, called by others obliquus auris and mufculus Externus auris.

EXTINGUISHING of Fires.— The world has long been in an opinion, that a more ready way than that in general ufe, might be found for extinguijbing fires in buildings, and it has teen generally attempted upon the doctrine of explofion. Zachary Greyl was the firft pcrfon who put this plan into execution with any tolerable degree of fuccefs. He contrived curtain engines eafily manageable, which he proved before fome perfons of the firft rank, to be of fufficicnt efficacy, and offered to difcover the fecret by which they were contrived, for a large premium given either from the crown or raifed by a fub- fcription of private perfons. But this fcheme meeting with no better fuccefs than things of this nature Ufually do, he died without making the difcovery : Two years after this the peo- ple who had his papers found the method, and it was fhewn before the king of Poland and a great concourfc of nobility at Drefden, and the fecret purchafed at a very confiderable price. After this the fame perfon carried the invention to Paris and many other places, and pradtifed it every where with fuccefs.

The fecret was this. A wooden vefTel was provided holding a very confiderable quantity of water, in the center of this there was fixt a cafe made of iron plates and filled with gun- powder ; from this vefTel to the head of the larger vefTel con- taining tire water, there was conveyed a tube or pipe, which might convey the fire very readily thro' the water to the gun- powder contained in the inner vefTel. This tube was filled with a preparation eafily taking fire and quickly burning away ; and the manner of ufing the thing was to convey it into the room or building where the fire was, with the powder in the tube lighted. The confequence of this was, that the powder in the inner cafe foon took fire, and with a great explofion burft the vefTel to pieces and difperfed the water every way ; thus was the fire put out in an inftaut, tho' the room was flaming before in all parts at once. The advantage of this invention was that at a fmall expence and with the help of a few people, a fire in its beginning might be extinguifhed ; but the thing was not fo general as it was at firft expected that it would prove, for tho' of certain efficacy in a cham- ber or clofe building, where a fire had but newly begun, yet when the mifchief had encreafed fo far that the houfc was fallen in, or the top open, the machine had n® effect. This was the thing firft difcovered by Greyl, and from which our chemift Godfrey took the hint of the machine, which he called the water-bomb, and would fain have brought into ufe in England. Aft. Eruditor. Ann. 1721. p. 183. See the ar- ticle WATER-Bomb.

EXTINGUISHMENT^/.;— Extinguishment «/Gw«- mon, in law. By purchafing of lands wherein a pcrfon hath common appendant, the common is exthiguijhed. Cro. El. 504. A relcafe of common in one acre, is an Extinguijhnunt of the whole common. Shower's, Rep. 350. And where a perfon hath common of Vicinage, if lie inclofes any part of the land, all the common is extinct. 1 Brownl. 174. If a man hath a high-way appendant to land, and afterwards purchafeth the land wherein the high-way is, the way is ex- tinct.

Extinguishment of Liberties, inlaw. If liberties and fran- chifes granted by the king, come again to the crown, they ' Ihail not be exttnguijhed; but it is otherwifc in the king's grants of felon's goods,- waifs, ftrays, wrecks, C3V. 9 Rep. 25.

EXTIRPATIONE, in law, a judicial writ, either before or after judgment, chat lies againft a perfon, who when a ver- dict is found againft him for kind, isfc. doth malicioufly over- throw any houfe, or extirpate any trees upon it. Reg. jud, 13. p. 56.

EXTRACT (Cycl.)— Mr. Gcoffroy who well knew the va- lue of this form of medicine, attempted to improve upon the common method of making Extracts, and fucceeded greatly to his wifiSes j the- confequence of which was his prefenting to the academy of fciences atParishis method of doing it. The hint was taken from a method ufed by the Count La- garais, to make what he called his eflential falts of plants ; which were only dry extracts, prepared by powdering the fubftance, and then keeping it in continual motion for fix or feven hours in fome common water, by means of a chocolate mill turned by a large horizontal wheel ; after the matter

■ had fubfided for an hour, the remaining liquor was poured off and evaporated over a balneum marue, or in the fun, and a valuable dry Extracl prepared. The method of this procek made it impracticable in large quanticics of medicines, and Mr. Gcoffroy removed the great difficulties that attended it by proving from repeated experiments, that boiling or infufing the fubftances in hot water, extracted from them all that was got out by the long motion of the mill; as was mltanccd in the moft familiar manner, in the common way of making tea and coffee, which were found to impregnate water with

as much of their virtue by the methods of infufion. and tic- cbetioh, as by ever fo long an operation in the' Count's me- thod. The expence of making. Extracts of this kind, can- hot but be greater than that of managing the fa.'iie me- dicines any cither Way ; but the eafe of taking, and the fiiin.Il dofe, cannot but fufKciently recommend them ; and according to Mr. Geoffroy's method, the fick may prepare them for himfelf. Mr. Gebfitoy gives forrie examples of his fuccefs in thefe preparations.

He took a dram of fcria in rjowdcr, and pouring on it a quantity of hot water he left it in infufion twenty- four hours, then filtering the infufibft he evaporated the liquor in -a bal- neum mariae, to the thicknefs of a thin iyrup; and fprcading this over the bottoms of two or thfee broad earthen plates he evaporated the remaining humidity over the fame balneum, and procured twenty-four grains of a dry Extrafl, wholly re- fembling Count Lagarais's falts, and operating in the fame manner and with the fame virtue as a dram of feria ; whether taken in powder, or bolus, or diflblved in an^ fluids, in any of which forms it had nothing of the naufeous taftc of fena. The reafon of fpreading the remainder of the firft evaporation Ort earthen plates is, that unlefs it be thus extended in a thin eruftitwill notdryregularly. The leaves of gratiola, which are a ftrong purge, being treated in the fame manner, gave the fame quantity of a dry Extracl, which proved a good purge in a dofe of eight, ten, or twelve grains. Other purgative medicines fucceeded on trial in the fame man- ner ; and every one muff be fenfible of the value of thefe pre- parationsj which will operate gently, yet fufliciently in a fmall dofe and in form of a taftelefs powder; when he cohfiders the neceffity bf giving purges to children ; and the antipathy many people have to the taking large doles of naufeous cathartics. Memoirs Acad. Sclcnc. Par, 1738.

The Peruvian bark, whofe virtues are fufRciently known, is another medicine very formidable from its large dofe. It ufed to be common to take two drams of it at once in powder when it came firft into practice ; but this dofe was found in- f importable, and infufions in wine and in water, and Ext7~a£is made in the common way, were ufed in its ftead : all thefe however ftill required large dofes, and retained the difagreeable taftc of the medicine ; but this is perfectly remedied by this method of making a dry Extracl, which reduces every dofe of the bark to one third of the quantity, and cures as certainly, as when taken in fubftance in the whole, fince the the juices of the Itomach could have extracted no more vir- tue 1 from the powder, than the water in the infufion from which this Extract was made does. The utmoifc care in making an Extracl from a dram of the bark with fpirit as well as water, can procure only twenty-four grains, the re- mainder being an infipid aild ufelefs matter ; it is plain there- fore that the whole virtue of the dram lies in this twenty- four grains, and fince this can be feparated by water and given alone, why fhould the palate be offended, or the Itomach loaded with fuch a quantity of ufelefs matter, as two thirds of every common dofe. It is very plain that the method of preparation of even thefe Extracts is very troublefome, but it is much lefs fo than that of Count Lagarais's falts, as it ipares the bufinefs of the mill ; but the fmallnefs of the dofe arid eafe of taking the medicines ufually moft of all difiiked, when reduced to this form, mult recommend it to thofe who are to give them to nice palates or tender conftitutions.

Extracts of writingsor records, are notes thereof. See Es- treat, Cycl.

EXTRACTA Curiae in our old writers, the ifTues or profits of holding a court, arifing from the cultomary fees, &c, Pe- roch. Antiq. 572.

EXTRACTOR, in midwifry, an inftrument contrived to ex- tract children in cafes of difficult births. We have the def- cription of a forceps for extracting children by the head, when lodged low in the pelvis of the mother, in the Medic. Efl". Edinb. Vol. 3. Art. 20. See alfo the Abridgment of this book Vol. 2. p. 438. where fome alteration is mentioned of this in- ftrument from Giftard's midwifry, and an improvement of it by Mr. Freke.

EXTRAC TUM Catharticum, a form of medicine in the Lon- don Difpcnfatory, intended as an equivalent for the Ex- trailum Rudii, commonly called Rudius's pill : it is made in this manner, take focotrine aloes an ounce and half, pith of coloquintida fix drams, fcammony, and the lefler cardamom feeds hufked, of each half an ounce, proof fpirit a pint ; pour the fpirit on the coloquintida cut fmall, then add the feeds bruifed ; draw a tincture with a gentle heat continued four days, then to the tincture prelTed out, add the aloes and fcam- mony firft feparately reduced to powder, and thefe being dif- folved draw off the fpirit, and reduce the mafs by evaporation to the confiftence of a pill. This is for many reafons a bettor compofition than the Rudius's pill. Pembertorfs, Lond. Dl- fpenf. p. 168.

EXTRAMUNDANE Space is the infinite, empty, void fpace, which is by fome fuppofed to be extended beyond the bounds of the univerfe, and confequently in which there is really no- thing at all.

EXTRA-PAROCHIAL, fignifies tobeoutofanyparifh; thus, where any thing is privileged, and exempt from the duties of

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