OCR Text |
Show ii INTRODUCTION. INTRODUCTION. in assertions were vague, unaccompanied with experiments, and unsupported by any firong arguments. Some of the more eminent anatomists suspected this doctrine, and asserted, that the lymphatics also absorbed fluids from surfaces, The late Dr. Hunter, particularly, taught this doctrine, and urged the following arguments in its favourz-The lacteals arise from the surfaces of the intestines, pass through the conglobate glands, terminate in the thoracic duct, and are, beyond dispute, absorbents. The lymphatics resemble the lactcals in a number ofcircumstancesz-Their Coats are equally thin and transparent; they are equally crowded with valves, for which no good reason can be given, supposing them to be continued, as has been imagined, from the arteries; they also pass through conglobate glands; they also, like the lacteals, appear to have no connexion with arteries, for they cannot be injected from them, as the red veins can; they also termi~ natc, at last, in the same common trunk with the lacteals, the thoracic duct; andlaftly, they too, appear to rise from surfaces; for ifthe venereal poison is applied to the surface of an ulcer, and passes into the blood, it passes through the lymphatic vessels, it sometitncs inilames their coats, and makes @9144:th , It H them, in consequence of this, appear in the form ofred lilies; it frequently inflames the glands through which they pass, and, some time after, shews itselfin the constitution, by symptoms peculiar to itself: on the contrary, ifsuch inflamed glands are. presently extirpated, the poison is removed with them, and the constitution will be prevented from beinginfectcd. He far- ther observed, that when injections thrown into the arteries or veins, were cxtravasated, from rupture ofthe vessels, they got into the cellular mem- brane, and very Commonly from thence into the lymphatic vessels; or if a tube loaded with quicksilver, was pushed, at random, into the cellular substance ofa gland (the testicle, for example) the quicksilver would frequently pass into the lymphatics of that part. The venereal and other poia sons passing into the lymphatics from the skin, proved their origin front surfaces; and the extravasatcd injections passing into the same vessels, from the cellular membrane, proved, in his opinion, their origin from cells. Thus, a grand system for absorption, in men and quadrupeds , was formed, and the laeteals and lymphatics were blended , under the common name of absorbc/r/s. Dr. Hunter enjoye d the honour of this discovery for many VCR l'S. u», , amt my qfiuwnum~;m.~ .7.: M "3m , years. At first professor Monro was his only rival. The medical world were not alwavs certain to which of these gentlemen the credit was due; but there were no doubts that one of the two was certainly entitled to it. Dr. Hunter, in his Medical Commentaries, supported his claim so well, that the greater part of those who were entitled to hold any opinion on the subject, were on his side. Lately, attempts have been made to wrest this discoverv from Dr. Hunter, and to give it to others. The same fate hapIened to Harvey, and happens to discoverers in general. When Harvey discovered the circulation of the blood, his opponents first attempted to prove that he was mistaken; but finding this ground untenable, they then asserted that it was known long before; Servetus, Columbus, and Ccsal- pinus, all knew it: and when they were informed, that if these gentlemen did know any thing Ofthc matter, the world at large. were totally ignorant of the fact, and likely to have continued so, except for Harvey, they once more shifted their ground, and said the discovery was of no use. Harvey, however, at present remains infull possession of his discovery; nor is there the smallest probability of his ever losing his title-Objections were made, and still are made to Dr. Hunter's theory. It was said, that the lacteals and lymphatics cannot form the absorbent system. In the first place, Hippocrates and Galen have asserted the absorption by red veins, and their au- thority has been deservedly respected. 2. Experiments tirade on purpose, by the moderns, are alleged, in confirmation ofthis absorption by red veins: they have imagined that they have proved that the veins arise from surfaces, by open months; for which structure no good reason can be given, unless they are absorbents. 3. Chyle has been supposed to have been actually seen in the. veins of the intestines: it could not be there unless they had absorbed it: and if \'Cll ' absorb on the mesentery, they must absorb every where else. 4. It is alleged, that there are parts of the human body, where no lymphatics are to be found. 5. The lymphatics which have been found, are not sufficiently numerous to be capable of performing so im- portant an ofiice as absorption. 6. It was also said, that there were no lymphatics in amphibious animals, in birds, and in fishes; absorption, therefore, in them, must be performed by the red veins: but ifrcd veins absorb in any of the classes of animals, it is more than probable they also 13 2 aborb |