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Show Expo/meals dcmonstmiiizg that red Veins do not absorb. Ea‘fit‘rimm/s drinms/ra/iz/g l/M/ I‘m] I'd/Is (/0 not alum [u bodies, have given me manyopportunities of seeing these vessels inflamed, from an irritating matter they had absorbed from such wound. Now, as I they do not absorb these poisons, or irritating matter; and if they do not blood, propelled it not only through the spunge, but into the veins. Dr. Fordycc says, there must be something else in the structure of these parts, not yet understood ; and rejects not only the solution I have given, of the passage ofblood into veins, but denies the possibility of venous absorption absorb on the intestines, nor on the surface ofthe body, nor from wounds, any where, on the principles of hydrostatics, independant of the other ar- 28 never, on stich occasion, found the veins inllamed, it is reasonable to infer that tht ' absorb no where else. the yen As patients are frequently infected with ‘al virus, without its liming previously inflamed any lymphatic gland, this circumstance may be considered by some as a proof of venous absorption; but it is not: all that it proves is that the poison sometimes is not able to inflame the glands, or that they are sometimes less irritable, and not easily inflamed. That veins absorb in the placenta, because lym~ phatics hax e not yet been found there, is no good argument. Lymphatics have been found in parts formerly suspected to have none; and in whole classes of animals, where it was said they did not exist: and the analogy is on the side of their being there; for if the Author of Nature found the lym- phatics necessary in all other parts, and if we are daily discoverinn niore ) then it is most probable that they exist in the placenta too, thou:h tl IC/V have not yet been found. D . When I ,said that there might be lymphatics in the placenta it ‘a th‘ ‘ ) ' child's portion; that ; I alluded to. Dr. Hunter believed that lymphatic " S sL existed here, similar to those Lister asserted he saw in the intestines and inesentery of birds, " dc aiihus fatetur Listerus brevia esse et in i'tlias finirl "-Haller. I know there are lymphatics in the mothei's iart~ but there the veins also arise by open months, out ofeclls and the i blood I ) contained inThh these cells enters ‘ these months .d4 _ , and minglcs' With the circulating; blood. ‘ ., aceoi mg to some, is clearly venous absorption: the b‘l‘lIC- lure of the corp ora cavernosa, penis, and clitoris, seems a good deal L to itscnifble that ofthc mothtr‘s part ofthe placenta ; and the veins appinir to arise rotn ‘ ' the, blood gets into V cells ther\e too. '{hat ' these vet' i fl't‘llltl‘. it :" ‘ , I, no not cells, . doubt; ' but I used to ex} )lain this, as t. circulation o f the U‘ L ‘ } blood not absorption, in the way Ilar\cv conceiv ed it to he in the otht‘rparts of' i > ' I t tnc body, nearly,- that is, he conceiv ed tl to blood to , be thrown from the .arteries f- . , ' in to aparen , V , oi_ spungy ehyma, ' tex titre, interposed betw ‘en the ends o aittries and beginning; of veins; and that the vis a tcrgo, in the arterial blood, guments I have given. 29 Supposing, says he, an opening made in a vein, there is a pressure equal to the force ofthc circulation in the veins, to force the blood out at this opening ; it would therefore flow out, and remain out, unless there was a force superior to this pressure to throw it in again : but we know of'no such force existing in the veins of the common structure. Nor is it possible that the vis a tcrgo, alleged by Harvey, can produce the supposed clfeets; for the cells of the supposed parenehyma, of the placenta, arid corpora eavernosa, mentioned, are not tense at the time of the. venous absorption, as it has been Called. \Ve know of no force in cavities capa« ble of overcoming the pressure ofthe venous blood on the sides of the ves- sels, and of propelling fluids into their supposed open extremities; though wc can easily conceive the muscular force of the lymphatics overcoming this pressure, in the angles between the jugulars and subclavians, for rea- sons whiclm ill be mentioned afterwards. But the supporters of venous absorption will perhaps still contend that I have concluded too hastily, respecting the impossibility of its existence; and that there are, after all, arguments in its favour, which are unanswerable. From the history of the human body, it will appear, say they, that more {luids have been absorbed in a given time, from the unity of the ins testines, than the lacteals could be supposed capable of taking up, or the thoracic duct, consistent \tith its diameter, or any probable v: lot'itv of the absorbed fluids, could possibly transmit. The diameter of the thoracic duct, in the middle of the back, says Haller, is not more than a line, or the tenth part of an inch; and it transmits not only the ehylc, but all the lymph of the lower extremities, of the contents of the pelvis, and of the cavity and parietcs of the abdomen. .\'o\\' Bocrhaave mentions a man who drank sixteen pints of wine daily; Haller ives examples of patients thinking 200 ounces of mineral waters in a few hours; but almost the \iholc of these fluids were soon after returncd by urine, \thich they could not have b en, |