( 84 ) 



" That absorption takes place through the veins of a limb was shown by Magendie 

 and Delille. Under opium, they severed all the parts save the artery and vein connecting 

 the leg of a dog with the trunk the vessels being isolated for a distance of four centi- 

 metres, and in one case the artery was replaced by a quill. On injecting Antiar upas 

 into the foot, the symptoms of poisoning set in just as soon as if the limb was in full 

 connection with the trunk." (Precis, p. 238, 1816.) J. Hunter tried to show that as 

 regards intestinal absorption, the lymphatics, i.e., the lacteals, were its exclusive agents. 

 (Medical Commentaries, V.) Hunter used hot milk placed in the intestine. 



" To prove that the rootlets of the portal vein were also concerned in absorption 

 various substances were injected into a loop of intestine of the dog. (1) Rhubarb decoction 

 disappeared from the gut, but none was found in the lymph of the thoracic duct. 

 (2) Prussiate of potash similarly injected was within a quarter of an hour found in the 

 urine, none in the lymph. (3) Dilute alcohol alcohol pure kills dogs ; the blood had an 

 odour of alcohol, the lymph none. (4) The thoracic duct ligatured in the neck ; on 

 giving the dog strychnine, it died promptly, as in a normal animal. (5) In a dog with 

 its thoracic duct ligatured, the same poison injected per rectum caused death just as 

 in intact animals. (6) The abdomen of a dog in full digestion was opened, a loop of 

 intestine 4 cm. long ligatured, and all the vessels, lymphatic and vascular, ligatured except 

 a mesenteric artery and vein. One hour after placing nux vomica in the gut, the 

 characteristic symptoms of its action appeared." 



The whole subject is very fully treated in his Plwnom&iie* 

 Physiques de la Vie (1842), and here we have the precursor of the 

 hypodermic method, viz., the "endermic." A blister is first applied 

 to remove part of the epidermis, and the drug applied to the exposed 

 surface (p. 35). Dame Nature had seen to the hypodermic injection 

 long, long ages ago. The groove in the poison fang of a serpent, the 

 embouchure of the channel under the protection of a sharp penetrative 

 point, is the prototype of the modern hypodermic needle. Still further 

 down in certain invertebrates this principle obtains. 



G. Valentin of Berne published in 1867 an important work on a 

 similar subject, Die physikalische Untersuchung d. Geivebe. 



" Tiedemann and Gmelin, of Heidelberg, have performed numerous experiments with 

 colouring matter and salts which are easily recognised or detected by reagents. 

 [Versuch iiber die Wege a. welchen Substanzen a. d. Magen u. Darmkanal ins Blut 

 gelangen, &c. (1820).] On examining the chyle several hours after colouring matters 

 have been given by the mouth, they have never found it tinged, although the colouring 

 substances were recognised in the blood and urine, and had already passed from the 

 stomach into the intestine. In very numerous experiments it was but a few times only 

 that some portion of the salt taken into the stomach could be detected in the chyle ; in a 

 horse to which some sulphate of iron had been given it was detected afterwards in the 

 chyle ; and once in a dog which had taken prussiate of potash, this salt was detectable 

 in the chyle, but in a second experiment this was not the case ; sulphocyanate of potash 

 given to a dog was also detected in the chyle. The objection, that the substances might 

 be already all absorbed, is not tenable ; for the intestine still contained a considerable 

 quantity of them." (Miiller's Phys., trans, by Baly.) 



J. L. POIfSEUILLE'S name remains associated with hsenio- 

 dynamics (1799, Paris-1869). He took his M.D. in Paris in 1828. 

 Three of the four important contributions that bear his name are : 



