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furnished with those curious vessels, or rather the openmouthed commencement of them, which are called lacteals. These are endowed with a remarkable power both of selection and of transmission; of selecting the chyliferous from the feculent portion of the digested aliment, and of transmitting it through the glands of the mesentery, for still further change, on to the circulation. And now, having thus traced the assimilating material from its reception by the mouth to its reception by the blood vessels, it falls in order that we should allude to the connexion that obtains between the digestive and other functions.
For this purpose it will be necessary to complete our anatomical and physiological sketch of the stomach and its appendages, by pointing out in a very general manner, the mode in which the digestive organization is supplied with nerves and blood vessels ; a particular to which we find none of our authors advert in the manner which might have been expected.
The nerves, which are more immediately derived from or connected with the brain, are principally those which supply the organs of sense. But there is one pair, the eighth, and two others, the fifth and sixth, which, besides supplying these organs, send branches down to form extensive communications with that part of the nervous organization which, under the denomination of the great sympathetic, supplies the stomach, the heart, the liver, and in fine, all the viscera of the chest and abdomen; so that an intimate association of parts and functions obtains, in such sort that integrity in the action of one organ goes far towards effecting a general harmony ; while, on the other hand, a disordered state of one part must necessarily, in a greater or a minor degree, interfere with this harmony. Then again, see how the stomach is connected in its blood vessels with other parts of the organization. Almost directly as the large descending blood-vessel from the heart emerges through the diaphragm, the large artery called the cæliac comes off, branches of which supply at once the stomach, the upper part of the intestines, and all the contiguous viscera. And there is one particular especially observable in reference to this head, viz. that the spleen, an organ which we have not hitherto named, seems to serve as a reservoir to the blood-vessels of the stomach, and to supply this last organ with a greater or smaller quantity of the vital Áuid according to the necessities of the case.
The spleen is a soft spungy substance, exceedingly vascular in its structure, and of a purplish hue. Its size and shape are different in different subjects; it is most generally, however,
of an oval form, and about five or six inches in length; lying just under the left extremity of the stomach, to which and to the pancreas it is fixed by means of blood vessels. This organ is, in fact, a collection of blood vessels, absorbents, and nerves, intermixed with cellular texture; and as it has no excretory duct, like the liver or the pancreas, it is natural to inquire for what purpose it is intended.
From the cæliac artery of which we have just spoken, a large branch, called the splenic, runs on to this organ; but, as it proceeds to its destination, branches are sent off from it to the pancreas, and to a portion of the stomach. So that, in reference to the structure and economy of the spleen, two circum• stances are especially worthy of remark; first, that its bloodvessels are among the largest of the body in proportion to the organ they supply; and secondly, that its blood vessels have very intimate union with those of the pancreas and stomach.
Now the time at which the stomach is most distended with food, is precisely the time in which a greater than ordinary supply of blood is demanded for the organ; and the stomach is so situated in reference to the spleen, that its distension by aliment, pressing upon the splenic artery, and thus causing an impediment to its current, directs more through those vessels which go to the pancreas and to the stomach itself. Thus, as we have seen that more bile is prepared and transmitted in proportion as more chyme is awaiting its influence, so, more blood is directed to the stomach by the very circumstance which creates the larger want. On this beautiful portion of the assimilating economy, we should have expected that writers on digestion would dilate more largely than we find the authors before us have done. There have been, indeed, some objections started respecting the absolute correctness of the principles now propounded ; but, in the main, we believe the inferences that have been deduced, will be found borne out by an examination of all the particulars connected with the chyliferous process. It strikes us, indeed, that the secretion of bile itself, as regulated by the demands of the stomach, may be greatly dependent upon the arrangement of blood vessels now alluded to; since the hepatic artery, which is a branch of the cæliac, has necessarily a considerable relation with the other ramifications from the same source. We are aware, that it is chiefly from the portal vein, and not from the hepatic artery, that the bile is thought to be derived ; but the more or less vigorous action of the liver, and consequently the kind and quantity of bile that is formed, cannot fail of having considerable reference to the degree of force with which even the arterial blood is transmitted to the organ. But we must not pursue this very curious path of research, lest it lead us too far beyond the prescribed limits of the present discussion.
If, then, the process of digestion has to do, both immediately and remotely, both mechanically and sympathetically, with other functions, how interesting is it to trace the sympathies and connexions of the stomach, by taking a general and combined view of the whole organization !
• All my philosophy,' says some author, with which I ' had been so deeply interested in the forenoon, appears non
sense and confusion to me after I have dined.' Why is it so? Partly because both nervous energy and circulating impetus are directed from the brain to the stomach and its immediate dependencies. And this, by the way, may account for that chilliness which weakly individuals are sensible of after meals ; which is vulgarly deemed a sign of health, but which ought rather to be put down in proof that the digestive process is going on regularly. And, in this sense, it is a signal of health; but then it is the most feeble who are the most sensible of this vicarious action of one part of the frame for another, upon principles that are sufficiently obvious.
Then, again, with regard to the connexion of the respiratory with the digestive function; the derangement of the one occa. sions the derangement of the other. This connexion may be in some degree mechanical, since a distended stomach interferes with the free action of the diaphragm, and consequently with freedom in respiration. But it is partly, and perhaps principally, mediate and sympathetic, since, as Dr. Paris properly remarks, 'the lungs are supplied with a part of the nerve of the eighth pair, and some filaments of the sympathetic, which will account for the sympathies which subsist between the • respiratory and the digestive organs.' To the same source we may attribute that remarkable relationship which is so frequently manifested between irregularity of the beart and deranged state of the stomach. Indeed, there is no organ or part that has not more or less of this dependence upon the state of the stomach : the kidneys and external surface of the body in a very marked manner exemplify this fact. The experiment of Lavoisier and Seguin have ascertained, that the cutaneous transpiration, or, as we call it, perspiration, is at its minimum during chymification, and at its maximum after the completion of that process. And certain kinds of eruptions on the skin are so manifestly dependent upon what has been received into the stomach, that an emetic which shall cause the ejection of its contents, shall immediately occasion the subsidence of the cutaneous disorder.
It has been above remarked, that the nervous and vascular connexions which are thus traceable by the anatomist, furnish a good deal of information to the physiologist in reference to the dependent and relative affections now referred to; but they do not, it must be admitted, explain the whole of the phenomena ; and if ever structure should furnish a satisfactory exposition of all the sympathies and peculiarities of the animate machine, our knowledge of it must be much more accurate than it is at present.
There is one particular connected with the digestive or assimilating process itself, which is still involved in considerable obscurity : we allude to the circumstance of liquids being conveyed from the stomach into the circulation, apparently by a different and less circuitous route than through that of the chyliferous vessels.
• It was long supposed,' says Dr. Paris, that liquids, like solids, passed through the pylorus into the small intestine, and were ab: sorbed together with the chyle, or rejected with the excrement. It is not asserted that this never occurs; but it is evident beyond con tradiction, that there exists another passage by which liquids can be conveyed to the circulation; for it has been proved, that if a ligature be applied round the pyloric orifice, in such a manner as to obstruct the passage into the duodenum, the disappearance of the liquid from the cavity of the stomach is not so much as retarded. It is evident, therefore, that there must exist some other passage, although its nature and direction remain a matter of conjecture.* I am strongly persuaded, that the vena porta (the large vein carrying blood to the liver) constitutes one of the avenues through which liquids enter the circulation; and in my Pharmacologia, I have expressed my belief, and supported it by various arguments, that through this channel, certain medicinal substances find their way into the blood. In order to discover whether drinks are absorbed along with the chyle, M. Majendie made a dog swallow a certain quantity of diluted alcohol during the igestion of his food; in balf an hour afterwards, the chyle was extracted and examined; it exhibited no traces of spirit ; but the blood exhaled a strong odour of it, and by distillation yielded a sensible quantity
* It has been proved by examinations after sudden death from intoxication, that part of the liquid ingesta has been transferred almost instantaneously even to the brain. Mr. Hare gives one or two remarkable instances of this ; and in Dr. Cooke's Treatise on Apoplexy, a case well authenticated is recorded, of a fluid being found in the ventricles of the brain exactly similar to gin, upon the inspection of the body of an individual whose death had been immediately occasioned by that spirit taken in a very large quantity. We assume, in these cases, the circumstance of immediate transference, since it must be effected before the vital spark is extinct.
• When liquids are introduced into the stomach, the changes which they undergo are determined by the nature of their composition.
• When a liquid holding nutritive matter in solution, is introduced into the stomach, it is either coagulated by the gastric juice, or its watery part is absorbed, and the solid matter deposited in the stomach*; in both cases, the product is afterwards chymified in the manner already described. "Milk appears to be the only liquid aliment which nature has prepared for our nourishment; but it seems that she has at the same time provided an agent for rendering it solid; hence, we may conclude that this form is an indispensable condition of bodies which are destined to undergo the process of chymification and chylification ; and that unless some provision had existed for the removal of aqueous fluids from the stomach, the digestive functions could not have been properly performed. When the broth of meat is introduced into the stomach, the watery part is carried off, and the gelatine, albumen, and fat are then converted into chyme. Wine and fermented liquors undergo a similar change; the alcohol which they contain, coagulates a portion of the gastric juices, and this residue, together with the extractive matter, gum, resin, and other principles which the liquid may contain, are then digested. Under certain circumstances, these liquids may observe a different law of decomposition, which will perhaps in some measure explain the different effects which such potations will produce: for example, the spirit may undergo a partial change in the stomach, and be even digested with the solid matter, or, on some occasions, be converted into an acid by a fermentative process. This will be more likely to occur in resinous liquors, which contain ingredients favourable to the production of such a change ; and hence, the less permanent and mischiev. ous effects of wine than of spirits. The liquid termed punch will, cateris paribus, produce a less intoxicating effect than an equivalent quantity of spirit and water; this may be accounted for by supposing that a portion of the alcohol is digested by the stomach into an acid; a process which is determined and accelerated by the presence of a fermentable acid like that of lemon, aided perhaps by the saccharine matter.
Oil, although possessed of the fluid form, does not appear to observe the laws which govern the disposal of these bodies; it is not absorbed, but it is entirely transformed into chyme in the stomach. To effect this, however, it seems essential that the stomach should be in a state of high energy, or it undergoes chemical decomposition and becomes rancid ; nor will the stomach, unless it be educated to it, like those of some northern nations, digest any considerable quan, tity of it; and since it cannot be absorbed, it must find its exit through the alimentary canal, and consequently prove laxative.'
We have presented this long extract from the classical production of Dr. Paris, partly because it clearly and ably explains the fact to which we have above adverted, in reference to the different circumstances under which liquid and solid ingesta eventually become integral portions of the circulating