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ELEMENTS OF MATERIA MEDICA.

be detected in the chyle, but some were found in the blood and urine.The odorous substances used were—camphor, musk, spirits of wine, oilof turpentine, Uippel’s oil, asafoetida, and garlic : they were for the mostpart detected in the blood and urine, but none were found in the chyle.The saline substances tried were—acetate of lead, acetate and cyanuretof mercury, chloruret and sulphate of iron, chloruret of barium, and ferro-cyanuret and sulplio-cyanuret of potassium. A few of these were detectedin the chyle, and most of them in the venous blood and urine. Fromthese experiments we may conclude, that although saline substancesoccasionally pass into the chyle, odorous and colouring matters do not;all the three classes of substances, however, are found in the venousblood. These results, observe Tiedemann and Gmelin, are opposed tothose of Lister, Musgrave, J. Hunter, Haller, Viridet, and Mattei, butagree with those of Halle, Dumas, Magendie , and Flandrin.

b. Magendie s experiment. —Magendie andDelille (Elem.Comp.Physiol.)performed a striking experiment, with the view of settling, if possible, thequestion of venous or lymphatic absorption of medicines and poisons. Theydivided all the parts of one of the posterior extremities of a dog, exceptthe artery and vein, the former being left entire, for the purpose of preserv-ing the life of the limb. A portion of the Upas Tieute was then appliedto a wound in the foot: in the short space of four minutes the effectsof the poison were evident, and in ten minutes death took place. To theinferences drawn from this experiment, however, several objections havebeen stated: first, the exhibition of opium, to diminish the pain of theoperation, has been said to vitiate the whole of the experiment; secondly,the coats of the arteries and veins contain lymphatics, by which absorp-tion might be carried on ; and thirdly, as the poison was introduced intoa wound, the poison might have combined with the blood, and haverendered it deleterious, without the process of absorption taking place.The first two of these objections have been obviated. In a second expe-riment, Magendie severed the artery and the vein, and reconnected themby quills, so as to preclude the possibility of absorption taking place bythe lymphatics of these vessels: the effects were the same. Some yearssince I assisted my friend Mr. Lloyd, assistant-surgeon of St. Bartholo-mew’s Hospital, in performing an analogous experiment, using Strychniainstead of Upas Tieute, and without administering opium: death tookplace in twelve minutes.

c. Lacteals tied: effects of poisons still produced. —Magendie says thatsymptoms of poisoning were observed in six minutes, when nux vomicawas applied to the intestine, though the lacteals had been tied.

d. Blood-vessels tied: poisons do not act. —Segalas tied the veins of aportion of intestine, and applied poison, but no effects were produced.Emmert observed, that when the abdominal aorta was tied, hydrocyanicacid was applied to the foot without producing any effect, but when theligature was removed, symptoms of poisoning came on. (Muller.)

e. Rapidity of absorption. —Mayer found that ferrocyanuret of potas-sium could be detected in the blood, in from two to five minutes after itsinjection into the lungs. The rapidity with which this salt enters theblood, says Miiller, is too great for it to be explained by means of theslow circulation of the lymph.

These circumstances appear to me to establish the fact of venousabsorption.