conveyance of my notions and I have added fome particular rules and cautions relating to cathartics, for the fake of young phyficians chiefly; who are often difpofed too rafhly to attempt, and too eagerly to embrace every novelty in practice, especially when handed down to them from perfons of whom they have a high opinion. For nothing can be fo univerfally ufeful, as not to be liable to fome exception; and it is fometimes as great a mark of found judgment, not to da milchief, as to do good *. Wherefore, not only in this cafe, but in all others within the compafs of our art, the physician ought conftantly to remember that of the poet t, Nothing does good, but what may also hurt. When I had finished this fall work, I thought it might be no lefs agreeable than ufeful to the gentlemen of the faculty, if to it I annexed Rhazes's treatife of the finall-pox and meafles, faithfully tranflated from the original Arabic into Latin: as it contains an ample detail of many things relating to the nature and cure of thefe difeafes, which, making proper allowances for time and place, coincide pretty much with the doctrines I have laid down. And indeed, it has given me no fmall pleasure, to fee my fentiments confirmed by the greatest physician of the age he lived in. But I have often wondered how it came to pass, that this book had never before been published either in Arabic, or in Latin from the Arabic. Robert Stephens was the first who published it in Greek, at the end of his edition of Alexander Trallian's work in the Hippocrates in his firft book of epidemics. † Ovid. trift. lib. ii. ver. z66.. year year 1548*. The Greek copy has been tranflated into Latin by three feveral perfons; the first of whom was Georgius Valla of Placentia, whofe verfion was published at Venice, A. D. 1498, and went through feveral editions. This was followed by a fecond, done by Johannes Guinterius of Andernac, printed at Strasbourg in 1 549 and Nicolaus Macchellus, a phyfician of Modena, put forth a third, printed at Venice, in 1555, and again, in 1586 +. Now, the Greek copy was not tranflated directly from the Arabic, but from a Syriac verfion, which latter feems to have been done for the ufe of the common people; and upon comparing the Greek with this Latin tranf lation from the Arabic, which I now publifh, it will appear very inaccurate, by the entire omiffion of fome things, and faulty rendering of others; whether through the infufficiency, or negligence of the Syriac or Greek tranflator, I fhall not determine. But the manner how I acquired my copy is this. After having caufed a diligent fearch to be made in our public libraries for an Arabic copy of this treatise to no purpose, I wrote to my good friend the celebrated Dr Boerhaave, profeffor of phyfic in the university of Leyden, entreating him to inform me, if fuch an one could be found in the public library there, which I knew to be very rich in Arabic manuscripts. A copy was accordingly found, which he got tranfcribed by the Arabic profeffor, and kindly fent it over to me; but it proved to be full of faults. This, however, I gave at two separate times to two gentlemen of character, to put it into Latin. One was So *The Greek title is, 'Pag λoyos megi doimixñs. + Vid. Fabricii bibl. Græc. vol. xii. p. 692. lomon lomon Negri, a native of Damafcus, extremely well verfed in all the oriental tongues; the other John Gagnier, Arabic reader at Oxford: and they both performed the task with great diligence. But upon comparing the two verfions I obferved that they differed in feveral places, not in the diction only, but even in the fenfe: wherefore, as I have no knowledge of the Arabic tongue, I could not determine which of the two to prefer. This uncertainty made me apply to my worthy friend, the Reverend Dr Thomas Hunt, for feveral years past Arabic profeffor in the university of Oxford, and lately made Hebrew profes‐ for likewise, who, among his many eminent qualities, is univerfally esteemed a great master of the eastern languages. This gentleman, at my request, generously undertook the province of strictly collating the two Latin verfions above mentioned with the Arabic copy, in my prefence; and out of them he compiled this, which I now give to the public; and doubtless he would have made it much better, had the Arabic copy been more correct, London, Sept. 29. 1747. A DISCOURSE on the SMALL B POX and MEASLES. CHA P. I. Of the origin of the fmall-pox. Efore I enter on the medical part of my fubject, I fhall briefly inquire into the origin of the fmall-pox, and the manner of its propagation from thofe countries where it firft appeared, almost over the whole face of the earth, as far as I can trace it in history for thefe points once fettled will throw a confiderable light on the nature of the diftemper, and the methods of cure, which I shall propofe in the féquel of the difcourfe. That this is a modern difeafe, whereby I mean, that it was not known to the ancient Greek and Roman phyficians, is to me a matter beyond all doubt. For I think they are widely mistaken who endeavour to prove, that the anthrax, epinyctis, and fuch like eruptions on the fkin, were our small pox: because it is more than probable, that the ancient phyficians, who were extremely diligent in the defcription and distinctive characteristics of all difeafes, would not have been content with barely mentioning this, which is fo contagious, and makes fuch dreadful havock among mankind; but would have minutely defcribed it, had they been acquainted with it. Wherefore we must have recourte to the writings of the Arabian physicians for the firft notices of this disease. The chief of thefe was Rhazes, who lived about about the year of Chrift 900. We have a large vo lume of this great man, published under the title of his Continent, a treasure of phyfic, which feems to have been compiled from his common-place book. In this he informs us, that a physician, whose name was Aaron, (who wrote thirty books of phyfic), had treated of the diagnostics, the various kinds, and the method of cure of the fmall-pox *. Now, this Aaron was born at Alexandria, and in the reign of Mohammed practifed about the year 622 †. Whence the learned Dr Freind conjectured, that poffibly the fmall-pox took its rife in Egypt 1. But the origin of the difeafe is carried farther back than the time of this Aaron, by Dr John James Reifke, who fays that he read the following words in an old Arabic manufcript of the public library at Leyden: "This year, in fine, the fmall pox and measles made their first appearance in Ara"bia." By this year he means that of the birth of Mohammed, which was the year of Chrift 572. Now, upon mature confideration of the whole affair, I am inclined to think that there are certain difeases, which are originally engendered and propagated in certain countries, as in their native foil. These by Hippocrates are called diseases of the country ; and fome of them, fprung up in various parts of Europe and Afia, from peculiar defects in the air, foil, and waters, he has moft accurately defcribed but the more modern Greeks call them endemic difeafes +. *Contin. 419. 2. † Vid. Abulpharajii hift. dynaft. p. 99. ↑ Oper. p. 330. || Hoc demum anno comparuerunt primum in terris Arabum variolæ & morbilli, Difp. inaug. Lug. Bat. 1746. + Νεσήματα ἐπιχώρια. + Lib. de aëre, aquis, & locis. ++'Evdness. Vid. Galen, com. i. in epidem. Hip. VOL. II. Р Thefe, |