Copy 1, Volume 1

The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good].

  • John Mason Good
Date:
1834
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Licence: Public Domain Mark

Credit: The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good]. Source: Wellcome Collection.

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    the liver, serious and fatal consequences would arise. The facts, on which this reasoning is founded, are highly interesting. Sir Everard Home formerly entertained a particular theory, that fluids passed from the stomach directly into the spleen. Though his observations disagree very much with those of Magendie, they corroborate one point maintained by the latter physiologist, namely, that fluids pass from the alimentary canal into the circulation by some other channel, than that of the chyliferous vessels. Strong arguments against Sir Everard Home’s particular theory are de- ducible from the fact, that, if it were true, animals certainly could not exist, or even enjoy good health, without a spleen. Sometimes the spleen is wanting in man*; and sometimes it has been removed from animals, which recovered and lived very well.+ The hypo- thesis also appears to be scarcely consistent with what happens in the horse, whose stomach, which is small in proportion to the size of the animal, could not contain the immense quantity of hay, grass, oats, and water, often consumed in a very short time; and from which organ, as was stated by Mr. Green, in his lectures at the College of Surgeons.in 1828, Professor Coleman had ascertained by experiments, that the passage of drink along the intestines was sometimes equal to the rate of ten feet in a minute. ] Chymificae | The means by which the food is broken down into pulp, after - tion. being received into the stomach, are various. In-the first place, the muscular tunic of the stomach acts upon it by a slight con- traction of its fibres; and, in connection with a certain degree of pressure, derived from the surrounding organs, produces, so far as this cause operates, a mechanical resolution. Secondly, the high _ temperature in the stomach produces a concoctive resolution. And, thirdly, the stomach itself secretes and pours forth from the mouths of its minute arteries a very powerful solvent, which is by far the chief agent in the process, and thus effects a chemical — resolution. In this manner, the moistened and masticated food is Chylifica- converted into chyme. It then passes into the duodenum, and tion. becomes mixed with the secretions poured into this organ from the pancreas, the liver, and the duodenum itself, and subject to their- -~ action; and hence its conversion into chyle. The whole process of digestion, therefore, as it occurs in the human body, to which the description now given chiefly applies, consists of three acts; mastication or chewing. chymification, and chylification. Indigest- Many substances are so hard and intractable as to sustain the ible sub- _ action of the digestive organs without any other change, than that ee of being softened or otherwise partially affected, instead of being | entirely subacted, and reduced to chyme or chyle. Such especially are the seeds of plants: and it is well worth observing, that, while birds or other animals derive from this kind of food a valuable © nutriment, notwithstanding its passing through them without being completely digested, the seeds themselves, that are thus acted upon, derive also a reciprocal benefit in many instances; and are — hereby rendered more easily capable of expanding in the soil, into which they are afterwards thrown as by accident, and have their * Lieutaud, tom. i. p. 234. + Th. Bartholini Anat., p.155. Lugd. Bat. 1686. Mayo’s Outlines of Phy- siology, p. 142. &
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