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CHAPTER XXVI. 



OF ABSORPTION. EXAMPLES. ANATOMY AND DISTRIBUTION OF THE 



ABSORBENT VESSELS AND GLANDS. ORIGIN OF THE ABSORBENTS. 



PROOFS OF ABSORPTION. CONTENTS OF THE ABSORBENTS. 



ANALYSIS OF CHYLE AND LYMPH. THEIR QUANTITY. MECHAN- 

 ISM OF THE ABSORBENT PROCESS. THE INFLUENCE OF THE 



QUALITIES OF THE FLUIDS. OF THE POROUS SOLIDS. OF PRES- 

 SURE. - OF MOTION OF THE FLUID WITHIN THE VESSELS. CON- 

 CLUDING OBSERVATIONS ON THE FUNCTION OF THE ABSORBENTS. 



THE function of absorption is universal in organized bodies, as 

 they all live and grow by absorbing suitable material from without, 

 and making it a part of themselves. All the tissues are more or 

 less porous, and capable of absorbing fluids brought into contact 

 with them. The cuticle of the hands soaked in water becomes soft 

 and swollen from the imbibition of that fluid, and if a soluble salt 

 be added to the water, this salt may, ere long, be detected in 

 distant parts of the body by its appropriate tests ; shewing that 

 the foreign substance has penetrated within the cuticle so as to 

 reach vessels capable of diffusing it throughout the frame.* In 

 the same way soluble substances taken into the mouth, and brought 

 into contact with the alimentary mucous membrane, are rapidly 

 absorbed, either immediately, or after having been first changed 

 and adapted for absorption by the processes described in the 

 preceding chapters. In a similar way gases or fluids effused or 



* Mr.Erichsen took advantage of a case of extroversion of the bladder to ex- 

 periment on the rapidity of absorption under different circumstances, as indi- 

 cated by the presence in the urine of the absorbed substances. The following are 

 some of his results. Prussiate of potass taken into the stomach, after a fast of 

 eleven hours, may be apparent in the urine in one minute ; but if immediately 

 after a meal, not till thirty-nine minutes. Vegetable infusions required more 

 time for passage through the system. Galls, uva ursi, madder, rhubarb, log- 

 wood, &c., passed in from sixteen to thirty-six minutes, according to the time 

 after a meal. Citrates and tartrates of potass and soda rendered the urine 

 alkaline in from thirty-six to forty-eight minutes. When the feet were im- 

 mersed in a pail of water containing three ounces of acetate of potass in solution, 

 the urine became alkaline in sixty-seven minutes ; but no effect seemed to be 

 produced when a solution of citrate, tartrate, or prussiate of potass was em- 

 ployed (see Med. Gazette, June, 1845). 



