OP ABSORPTION. 37 



3. The fluid* and solutions injected into the lungs are absorbed more or less quick- 

 ly, according to their nature, and their degree of concentration. 



4 U This absorption is in general very great, but is less in young and newly born 

 animals than in adults. 



5. Absorption takes place by the pulmonary veins, for it has occurred in the space 

 of three minutes ; the fluids injected are found in the blood before they are perceived 

 in the chyle ; they are found in the chyle : they are found in the left auricle. Lastly, 

 absorptio'n is carried on even although the thoracic duct be tied. 



6. Absorption is likewise performed by the lymphatic vessels, but more slowly. 



7 Q . The veins of the -stomach and intestines also absorb, but in much smaller quan- 

 tities. 



8. The existence of fluids absorbed by the veins can be demonstrated in the blood. 

 It is easy to discover there the prussiate of potass, the muriate of iron, arsenic, &c. 

 The prussiate of potass injected into the lungs can be traced, first in the arterial blood 

 of the heart and arteries, then, if the injection be continued, in the venous blood. 



9 Q . These substances can be discovered in abundance in the urine in the bladder, 

 and in that in the kidneys. The prussiate of potass can be discovered in it seven mi- 

 nutes after the injection. 



10, The prussiate of potass is likewise deposited, and even in considerable quan- 

 tity, in the serum of the pericardium, of the pleura, of the peritonaeum, in the synovia, 

 under the skin, and in the milk. 



li y , When the prussiate of potass is injected, it can be discovered after some hours, 

 not only in the fluids, but also in many of the solids : several of these, parts then be- 

 come green or blue with the muriate of iron, viz. the cellular tissue uHder the skin, 

 and in the whole body, the fat, the serous and fibrous membranes, the aponerouses of 

 the muscles, tendons, the dura mater, periosteum, &c. 



12. The membranes of the arteries and veins 5 even the valves of the heart can be 

 thus entirely coloured blue by the same agent. 



15. The parenchyma of the liver and spleen cannot be coloured blue, but some- 

 times the cellular tissue around their great vessels. The lungs, the heart, and the kid- 

 neys, can be coloured blue. 



15. The substance of the bones and their marrow, the substance of the muscles 

 and that of the brain, spinal marrow, and nerves, evince no change of colour with 

 the muriate of iron. The nerves of the brain and spinal marrow seem to exert a re- 

 pulsive and exclusive force, on the contact of fluids foreign to their nutrition. It may 

 be concluded from this that the opinions of many physiologists, that poisons act mor- 

 tally, when they are applied to these parts of the nervous system, are not well founded, 

 and are devoid of direct proofs. 



16. These experiments may also throw some light on secretion, the reproduction 

 and nourishment of bodies ; they teach, moreover, the passage of liquids from the mo- 

 ther to the foetus. When the prussiate of potass has been administered to the mother, 

 it can be detected in the water of the amnion, in that of the chorion, and of the um- 

 bilical vesicle, in the liquid of the stomach, in many solid parts of the foetus, for ex- 

 ample, in the kidneys, in the stomach, &c. as also in the placenta. When a foe- 

 tus, to the mother of which prussiate of potass has been given, is placed into a mixture 

 of spirit of wine and muriate of iron, it becomes blue coloured. Thus we acquire a 

 certain proof of the passage of fluids from the mother to the fcetus, a proof that has 

 been vainly sought for until now : the fluids taken into the blood of the mother are 

 deposited in the tissue of the placenta, and are thence absorbed by the veins of the 

 foetus* 



FIL Of the manner in which Absorption in performed; andef Exhalation. M. Magen- 

 die (Journal de Physiol, Experiment. JVo. I.} infers that the chyhferous vessels absorb 

 chyle only, and that the veins possess the faculty of absorption. He has endeavoured 

 to disprove the absorbent power of the lymphatic vessels, but in this lie has not suc- 

 ceeded. He considers also that his experiments justify him in concluding, that, in all 

 cases where artificial or real plethora exists, and the veins consequently are distended, 

 no absorption takes place, or only in a slight degree, and after a greater lengt.li of time, 

 than under ordinary circumstances ; whilst, when the original quantity of blood is di- 

 minished by venesection, absorption follows in one-fourth of the time in which it is 

 found to occur when depletion has not been previously had recourse to. He considers 

 it therefore, to follow, that absorption is influenced by the congestion and caliber of 

 the blood-vessel;}. 



" The further pursuit of these researches led M. Magendie to the conclusion, -that 

 absorption is nothing more than the well-known phenomena of capillary contraction* 

 which takes place vhen tubes Of a smell rnlibre are' immersed in fluids: a pheno- 



