^ ON THE FUNCTION OF DIGESTION; ITS DISOKDERS, AND THEIR TREATMENT. 4SI81 A TREATISE FUNCTION OF DIGESTION: ITS DISORDERS, AND THEIR TEEATMENT, F. W. PAVY, M.D., F.R.S., FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS ; SENIOR ASSISTANT-PHYSICIAN TO, AND LECTURER ON PHYSIOLOGY AT, GUY'S HOSPITAL. From the Second London Edition, PHILADELPHIA: HENRY C. LEA. 18 6 9. CAXTON PRESS OF SHKRMAN & CO. PREFACE TO THE SECOND EDITION. But little more than a year had elapsed from the first appearance of this work when I received an in- timation from my i^ublishers that a second edition was required. I was then occupied in preparing a second edition of my work on Diabetes, and I pur- posed as soon as this should be completed, writing an article on Food, to be added to the contents of the present volume. Finding, however, upon mapping out what I designed undertaking, that from recent discoveries so vast a field for discussion was thrown open, and that what would have to be said would carry me far beyond the space I had originally al- lotted, besides entailing an undesirable delay in the reappearance of this work, I resolved upon reissuing it as it stood, and bringing out my remarks on Food in the form of a separate work, in w^liich I propose to treat the subject in detail under both a theoreti- cal and practical point of view. 85 Grosvexor Street, Grosvenor Square, February, 1869. 62104S CONTENTS. PAGE General Kemarks on Digestion and Indigestion, . . 17 Prehension and Ingestion, 25 Mastication, 26 Insalivation, 31 Deglutition, 41 Difficulty of Swallowing, or Dysphagia, .... 48 Gastric Digestion, 57 Vomiting, 106 Eructation. — Kumination, ........ 127 Perverted Appetite, 135 Pain and other Morbid Sensations connected with the Stomach, 137 Flatulence, 144 Heartburn, 148 Water-brash, 150 Acidity, 157 Intestinal Digestion, 161 Colic. — Enteralgia, 213 Intestinal Flatulence. — Tympanites, 217 Diarrhcea, 220 Constipation, 229 On Artificial Digestion as a Means of Dissolving Meat FOR Producing an x\rticle of ^N'ourishment for the Invalid, 242 GENERAL REMARKS ox DIGESTION AND INDIGESTION, The purport of digestion is the preparation of food for absorption; and its performance as one of the functions of life is called for by the circumstance, that the fluid state forms a necessary condition for the accomplishment of absorption. In organisms belong- ing to the vegetable kingdom, an absence of a diges- tive system is to be remarked, because their food, con- sisting, as it does, of inorganic principles diffused through the atmosphere and dissolved in the moist- ure percolating the earth, is already in a fit state for absorption by the leaves and roots — the absorbing organs of the plant. In some few animal organisms, also, for a similar reason, there is an absence of di- gestive apparatus. In the generality of animal be- ings, however, the food is of a nature to require prep- aration before it is susceptible of absorption. Hence the demand for digestion as one of the functions of animal life. Digestion, in a limited sense, may be taken as sig- nifying the phenomena that occur in the stomach and intestine immediately antecedent to absorption; but 2 18 GENERAL REMARKS ON looked at comprehensively, the light under which it will be regarded in the following pages, the various operations accessory to this final act are also included as 23arts of the process. Now, the first step to be taken towards the accom- plishment of digestion are prehension and ingestion. Food must be secured and introduced into the mouth before it can be eaten and digested. In the cavity of the mouth two operations are per- formed — MASTICATION and INSALIVATION : the one con- sisting of a mechanical reduction of the food to a more or less minute state of subdivision ; the other, its incorporation with a secretion poured out by a set of glands specially provided for the purpose. Thus much accomplished, the food is formed at the back of the mouth into a bolus, and then propelled, by the process of deglutition, along a canal formed by the pharynx above and gullet below, into the stomach. Arrived in the stomach, one of the chief acts of the digestive process is performed, viz., chymification, or GASTRIC DIGESTION. The food is brought in contact with a fluid — the product of secretion of the organ — which is endowed with a strikingly energetic solvent power over certain of the alimentary principles. By the agency of this secretion a semifluid material is formed, called chyme, which constitutes the product of gastric digestion. Having reached the state of chyme, the food passes from the stomach into the small intestines, where it becomes incorporated with various secretions, the general effect of which is to cause the transformation DIGESTION AND INDIGESTION. 19 of the watery-looking chyme into a rich cream-like magma. This constitutes chylification or intestinal DIGESTION. The term chylification, however, signify- ing the production of a chyle-like magma, as repre- senting the effect of intestinal digestion, may have suited the older physiologists ; but with the knowl- edge that is now possessed it conveys a very imper- fect notion, as will be subsequently seen in the fol- lowing pages, of what is in reality accomplished. With intestinal digestion is completed the actual digestive process. The resulting phenomena are two, absokption and defecation. As the digested aliment is slowly propelled along the small intestine by its peristaltic movement, the villi, or little absorbing organs with which its surface is so thickly studded, pick out the nutritive elements and discharge them into the lac teals, by which set of vessels they are con- ducted into the circulatory system, to replenish its contents or compensate for the constant extraction that is going on for the growth and maintenance of the body. Those portions of the ingesta that escape digestion and remain unabsorbed are gradually urged along towards the outlet of the alimentary tract, and thence expelled as useless matter from the economy. As long as a healthy state of the digestive organs exists, and the process of digestion is naturally performed, we have no knowledge from our feelings that anything is going on. We ought not indeed to be cognizant by any feeling experienced of having a digestive apparatus or a function of digestion to per- form. Beyond a sense of comfort and satisfaction, there ought to be no sensation produced by the inges- 20 GENERAL REMARKS ON tion of a meal at its appropriate time. Such in a perfect state of health also^ applies to all the func- tional operations of tlie body. Each and every one of them should be performed without our being made specially aware that either of them is being carried on. If, instead of a sense of comfort and satisfaction, a state of uneasiness follows the ingestion of a meal, it may be taken either that the amount of food con- sumed has been beyond the natural limit — beyond what the natural digestive powers are equal to di- gesting; or that the digestive organs are not perform- ing their work in a natural way. Indigestion, or dyspepsia, is said to exist when digestion fails to be performed in a healthy manner. The deviation from health may amount only to a slight sense of oppres- sion, weight, or distension ; or it may consist of one or more of the various manifestations of deranged action treated of in the following pages. Digestion, as has been mentioned, consists of a series of operations, some of which constitute only accessory, whilst the others form the essential parts of the process. Now, it is only to deranged action having reference to the latter that the terms indiges- tion and dyspepsia appl}^ There may be a defective performance of an accessory operation which may- lead to indigestion, but such defect does not in itself fall within the range of meaning of the term. Defec- tive mastication, for example, may lead to indiges- tion, but no one looks upon imperfect mastication as constituting a form of indigestion. So in defective deglutition, there is a deranged performance of one of the operations of the digestive process — a derange- DIGESTION AND INDIGESTION. 21 ment whereby the accomplishment of digestion may be more or less frustrated ; but no one classifies dys- phagia under the head of indigestion. Looking at indigestion, then, which is thus limited to derangements connected with the accomplishment of the ultimate operations of the digestive process — in other words, to derangements connected with the performance of gastric and intestinal digestion — the symptoms that may be observed are numerous and diverse. They fall, however, under three categories, being all referable either to (1) perverted sensibility, (2) perverted muscular action, or (3) perverted secre- tion. The divers symptoms belonging to indigestion may be encountered, either singly or variously combined, in different cases. Sometimes they occur under such a form as to appear more like individual affections than symptoms of a general disorder. The symptoms, also, produced by indigestion are not confined to symptoms of derangement of the digestive function only. The disordered state exist- ing maj^, through reflex influence, affect other parts, and so lead to the occurrence of deranged actions elsewhere. And such is the range of sympathy that exists between the digestive organs and other parts, that the functional disturbances forming occasional concomitants of dyspepsia are almost as multifarious as those belonging to hysteria. The brain, heart, lungs, liver, kidneys, and skin, all, may betoken sympathy with a deranged state of the digestive organs; and so closely do the sympathetic disturb- ances produced sometimes simulate the phenomena 22 GENERAL REMARKS ON of primary disease in the part affected, that close attention is often required to discriminate the differ- ence. There is no comphaint that the physician is so fre- quently called upon to treat, in one shape or another, as that of indigestion; and this arises from the nature of the position the digestive organs occupy. As with other maladies, indigestion may be due to an in- herited weakness of the organs, or to some other internal cause; but in by far the majority of instances it is by an influence of an external nature that the complaint is brought on. Errors in eating and drink- ing form undoubtedly the most fruitful source of the complaint ; and looking at the quantitj^ and quality of the articles that are often put into the stomach — looking at the unnatural mode of living so common around us — the wonder is that the digestive organs escape being morbidly influenced by the unnatural circumstances to which they are exposed as freely as they do. ^y overtaxing the digestive powers a dis- ordered state of the digestive organs may be brought about, just in the same manner, as is well known, disordered states of the brain and vocal apparatus are brought about by over-mental application and over-exercise of the voice. It has been mentioned that, besides hereditary dis- position, there are other internal conditions to which dyspepsia may be attributable. As various functional disturbances arise from derangement of the digestive organs, so a disturbance of the function of digestion is produced by derangements existing elsew^here. Digestion is the result of the exercise of a power DIGESTION AND INDIGESTION. 23 dependent upon the action of certain secretions. Now, the production of these secretions is a vital operation, and is subject, therefore, to the general state, as to health and vigor, that may happen to exist. Under a seriously deranged state of the sys- tem, with the functions of life generally disturbed, it is hardly to be expected that the secreting action of the digestive organs should continue unimpaired. The secreting power being at fault, defective digestion and its various concurrent phenomena follow as a consequence. Pathology has not thrown much light upon the subject of dyspepsia. It is true, structural change in the organs is often met with to account for the mani- festations of deranged action that have been observed; but cases frequently happen where strongly marked symptoms of dyspepsia have been remarked during life without there being, even under microscopic ex- amination, any appreciable textural alteration dis- coverable after death. There is nothing, hoAvever, that should excite astonishment in this; for we might just as reasonably expect to find structural change in the muscles in every case of disordered muscular action as structural change in the digestive apparatus in every case of disordered digestion. Whilst the several manifestations of deranged di- gestion separately considered in the present work call for their special measures of treatment, the fact that they form symptoms of a general disorder must, never- theless, not be lost sight of. The case, in other words, requires to be looked at in its entirety — requires to be viewed comprehensively, instead of wholly confining 24 GENERAL REMARKS ON DIGESTION, ETC. the attention to this or that phenomenon which may happen to form the prominent symptom of complaint. In the treatment of all cases of deranged digestion it is of the first importance to pay strict attention to the diet. One of the great objects in medical prac- tice generally is to lighten, as far as can be done, the work of any part of the system that may show signs of impairment ; and, upon this principle, the diet in disordered digestion should be such as to keep the work to be performed within the range of power that happens to exist for adequately performing it. The quality and quantity of the food, as well as the periods at which it is taken, must be properly regulated. Without this, other measures will be useless, and the treatment defeated. PREHENSION AND INGESTION. To secure our food and introduce it into the mouth form the first steps that must needs be taken towards the performance of digestion. On looking through the animal kingdom, various are the devices that are observed for adapting different organs to the dis- charge of these offices, according to the special cir- cumstances that exist. In man, the hands and lips form the instruments respectively designed by nature for the operations of prehension and ingestion. The hand, it may be observed, is susceptible of applica- tion, under the direction of man's intellect, to a mul- tiplicity of purposes besides that of prehension; but that prehension is its fundamental intention may be inferred from its constituting the primary use to which it is applied in the child. Before there is mental de- velopment or intelligence sufficient to prompt it to the execution of any other designed movement, an object placed within reach of the hand is almost sure to be grasped and carried to the mouth. The existence of disease about the mouth may in- terfere with the accomplishment of ingestion, and so frustrate the due performance of digestion. As re- gards prehension, however, our social state renders it scarcely likely, although such may occur amongst the lower animals, for digestion to be defeated through physical defect implicating the performance of this part of the process. MASTICATION. Mastication is directed towards the reduction of our food to a minutelj^ divided state, so that it may more readil}^ yield to the digestive influence of the secretions with wdiich it is subsequently brought into contact. Its purport is the same as the process of pounding in a mortar, to which the chemist subjects a solid substance that he desires to place in a favora- ble state for solution. A preparatory act to digestion, this comminution of food is in most animals effected in the mouth, or what may be styled the ante-chamber to the digestive passages ; the teeth constituting the organs by means of which the process is accomplished. In many, how- ever, as in the wdiole of the bird tribe, and some other animals besides, no comminuting apparatus is met with in the mouth, but in its stead an organ, the gizzard, is found, which is carried some distance down along the digestive tract, and placed in the abdominal cavity. Different varieties of teeth are provided for the dif- ferent purposes to be fulfilled, and throughout the animal series a beautiful harmony can be traced be- tween the general character they present and the nature of the food destined to be consumed. The principal varieties are the incisors, or cutting teeth ; MASTICATION. 27 the canines, or tearing teeth ; and the molars, or grind- ing teeth. The incisors are phaced in the front of the mouth, and are met with in their highest state of develop- ment in the mammalian group of rodents, comprising animals such as the squirrel, rabbit, rat, mouse, etc. They here constitute true chisel-like instruments, and, in their construction and mode of growth, pro- vision is made for the constant retention of a sharp, chisel-like edge. The canines are situated just behind the incisors. They are pointed in form, and adapted for enabling secure hold to be taken of an object that has been grasped by the mouth. They are seen in their most characteristic state in the mouth of the lion, tiger, and other members of the carnivorous order. The molars are encountered at the back of the mouth. They present an expanded surface, adapt- ing them for their office of pounding or crushing the food. It is in the herbivorous animal — as the ele- phant, horse, sheep, etc. — where this kind of tooth attains its most perfect grade of development ; and here, unlike as with our own molars, the three com- ponent structures of the tooth — enamel, dentine, and crusta petrosa — which differ considerably in degree of hardness from each other, are arranged under the form of consecutive vertical plates, repeated series after series throughout the tooth. By such a plan of construction, the wear is rendered unequal, and the retention of a permanently uneven surface — a condition required for the process of reduction or grinding to be effectively performed — is secured. 28 MASTICATION. Corresponding with the phites of the softest material there exist depressions on the surface, as these yield the most readilj^ to the effects of wear. For a con- verse reason, the hardest plates stand out as promi- nent lines or ridges. Thus, so perfect are nature's arrangements, instead of this compound molar tooth of the herbivorous animal grinding down to an even surface, and thereby becoming a less effective instru- ment by use, its actual wear maintains it in a con- stant state of efficiency. The above varieties of teeth are all of them present in man, each being found in a moderate state of de- velopment. . The condition of man's dentition, as regards development of the several varieties of teeth, thus occupies an intermediate position, and furnishes one of the arguments to be adduced in favor of a mixed diet forming that which is designed by nature for his support. We are provided with two sets of teeth during the course of life. The first or deciduous teeth are twenty in number, and in size and strength are adapted to the mouth and power of the muscles be- longing to early years. As childhood is emerged from, these teeth are gradually shed, and replaced by a larger, stronger, and more numerous set. The permanent teeth are thirty-two instead of twenty in number; and in their general characters they con- form to the increased size of the jaws and strength of the masticatory muscles belonging to later years. An interval elapses between birth and the evolu- tion of the first set of teeth; and for this period of life it happens that the sustenance provided for us MASTICATION. 29 by nature does not call for any performance of masti- cation. Thus the production of a liquid support by the female parent for the sustenance of her offspring, during the earliest period of independent existence, is in harmony with the edentulous condition of the mouth existing at this time. As teeth make their appearance, the mouth becomes fitted for the reduc- tion of solid food. The evolution, therefore, of these organs may be taken as affording a sort of physio- logical indication of the age at which the child should be weaned from its maternal support, and be supplied with solid matter as food. By the tenth to the twelfth month, from eight to twelve teeth have usually made their appearance in the mouth; and these would be perfectly meaningless with a continued subsistence upon a fluid diet. It may now be considered that some light kind of solid food is intended to be taken, because organs for its reduction have made their appearance, and are fxirly progressing, in respect of the first or temporary set, towards completion. From the belief — and it is a belief which certainly in the case of many cannot be pronounced as un- founded — that childbearing is held in check during the continuance of suckling, it is not uncommon amongst the poorer classes to meet with instances in which weaning is delayed till a much later period than the tenth or twelfth month. The impairment of health in the mother, and frequently in both mother and child, that such prolonged lactation is so often found to entail, shows that the dictates of nature upon this matter cannot be fearlessly disregarded. Some pretend to be ignorant of there being anything 30 MASTICATION. likely to be hurtful, or anything unnatural in the course adopted. Having ascertained from them that a fair number of teeth exist in their infant's mouth, the question may be put, by ^yRy of argument to bring home to them their mistake, whether it is thought that these teeth were placed there by nature for nothing, as nothing is required of them under sustenance upon the food Avhich is being given. Defective mastication, arising either from a habit of too hastily eating — or bolting the food, or from a faulty condition of the masticatory organs, forms a frequent source of imperfect digestion. The more minute the state of subdivision to which the food is reduced in the mouth, the greater will be the facility with which it subsequent^ yields to the solvent in- fluence of the secretions with which it is brought in contact. Food swallowed in solid portions may, by the resistance offered to digestion, act as a source of irritation, and occasion a deranged state of the diges- tive organs. All persons, but especially those of a dyspeptic habit — those possessing weak digestive powers — should deliberately masticate or thoroughly comminute their food in the mill that nature has provided for the purpose, before it is swallowed. The state of perfection to which modern dentistry has risen leaves no room for complaint of inability to properly perform the function of mastication through the existence of a faulty condition of the machinery for the purpose. Whatever the imperfections and de- ficiencies that may arise to nature's dental apparatus, the resources of art are nowadays found equal to meet the case. INSALIVATION. A FLUID known as saliva is poured into the mouth, and incorporated with the food whilst it is being re- duced by the process of mastication. This fluid is derived from certain large glandular organs lodged in the neighboring locality, and a multitude of little glandular masses scattered beneath the mucous mem- brane surrounding the cavity of the mouth. The large glands exist in pairs, respectively symmetrical on the two sides. They form the two parotid, two sub- maxillary, and two sublingual glands. The secretion of the parotid reaches the mouth through a duct, which perforates the mucous mem- brane of the cheek, and terminates opposite the second upper molar tooth. The secretion of the submaxillary is poured into the mouth through a duct the termination of which may be recognized in the living subject upon the sum- mit of a papilla to be seen by the side of the frcenum Uncpice, just behind the incisor teeth of the lower jaw. The sublingual gland is provided with several small ducts, some of wdiich open into the submaxillary duct, whilst the others directly pierce the mucous mem- brane lying over the gland along a ridge-like eleva- tion which marks its position in the floor of the mouth underneath the tongue. 2 INSALIYATION. The scattered glands, each of which is provided with its own little duct opening upon the surface ahove, are named from their jDOsition: the labial, buccal, palatine, and lingual glands. In ultimate structure, all these glands resemble each other. Each consists of a branched duct termi- natins: in a series of vesicular dilatations formed of a homogeneous layer called memhrana irropria^ or base- ment membrane. Within this vesicular extension of basement membrane is a lining composed of epithelial cells; and, on the other side of it, a vascular expan- sion consisting of capillary bloodvessels. The only difference between the glands is as to external form and size. In the larger glandular structures the lob- ules are aggregated around a common duct so as to form a compact circumscribed mass. In the others, the lobules are spread out over an extended surface, each forming an isolated mass, provided with an in- dependent little duct, through which the secretion is discharged directly into the mouth. The view entertained with regard to the manner in which the process of secretion, in these, as in glands generall3^, is effected, is that from the plasma which escapes from the capiUaries around the vesicular ex- tremities of the duct, the epithelial cells within select certain materials — their appropriate elements of growth, which they afterwards give up, by rupture or solution of their cell-wall, to pass down through the duct, and form the product of secretion, that flows from the gland. The varietj' existing in the compo- sition of the different secretions depends upon the selective property of the cell, it being the province of INSALIYATION. 33 the cell of one gland to select or appropriate certain materials ; and of the cell of another gland, other materials for its growth. The cells, also, besides their selective endowment, must possess the 23ower of ex- ercising a transformative influence over some of their contents : organic principles being met with in the secretions that do not exist in the blood. Mixed saliva, or the salivary secretion obtained from the mouth, presents itself as an opalescent, color- less or faintly bluish-white, tasteless, inodorous, and somewhat turbid and viscid liquid. Its sp. gr. is but little above that of water, usually ranging from 1004 to 1006. Its natural reaction has formed a subject of dispute amongst physiologists. The usual reaction encountered is that of alkalinity, but the test paper may show the existence of a neutral or even an acid state. This want of uniformity seems to have been made out to depend upon the relative amount of actual saliva, and of mucous secretion that may hap- pen to be present in the mouth at the time. The product of secretion of the salivary glands in a state of health is invariably alkaline, whilst the mucus, or product of secretion of the mucous membrane of the mouth, is on the other hand acid. Hence, if the mouth be examined at a period, as during a state of activity, when saliva is flowing from the salivary glands, an alkaline behavior is the one that will be discovered. Taken, however, at a period of inac- tivity, no saliva happening to be present, the mucous secretion may cause ^n acid reaction to be encoun- tered. The origin of a neutral state, after what has 3 34 INSALIYATION. been said, follows without requiring any special ex- planation. The pure secretions obtained direct from the sali- vary glands are perfectly transparent instead of ojDal- escent liked mixed saliva. Although agreeing with each other in this respect, they strikingly differ as regards fluidity. Whilst, for instance, the secretion from the parotid is almost as thin as water, and that from the sublingual viscid in the extreme, that from the submaxillary is of an intermediate character. Ptyaline is the name that has been given to the nitrogenized principle which forms the special organic constituent of saliva. Like diastase of the vegetable kingdom, this principle enjoys the property of acting as a ferment upon starch, and converting it into sugar. Amongst the saline ingredients of saliva is one, the sulphocyanide of potassium, which cannot be looked upon as otherwise than a strange chemical compound to be present in a normal product of the animal econ- omy. It is easily recognized by its behavior with a persalt of iron, and has not been encountered any- where else in the system. Eberle has suggested that the presence of a sulpho- cyanide in saliva is connected, like the morbid condi- tion of the saliva in hydrophobia, with the existence of a particular state of the nervous system. To pro- cure pure saliva, he says, it is necessary to collect it fasting. The following is an account of the plan he adopted upon himself: After rising in the morning, coughing, spitting, and rinsing his mouth out with water to cleanse the mucous surface, he took a walk to put himself in a good humor. Returning home. INSALIVATION. 35 he sat down and placed a basin in his lap, over which he held his head, allowing his saliva to flow into it as it was secreted, whilst he thought of something agreeable, particularly of some kind of food that he relished. The saliva thus secreted was, according to Eberle, perfectly normal, and devoid of sulphocya- nide. If, now, whilst it was thus being collected, he happened to think of anything disagreeable, particu- larly of his enemies, it immediately changed in char- acter, and became charged with sulphocyanide. No physiologists, comments Bernard on this statement, besides Eberle, has had imagination enough to pro- cure a like result. From about fifteen to twenty ounces is the estima- ted average quantity of saliva secreted in man in the twenty-four hours. The determination, however, is a difficult matter to effect, and it cannot be considered that anything of a reliable nature is known upon this point. The amount of secretion produced will vary with the quantity and quality of the food ingested. When the mouth is in a state of quiescence, there is little or no saliva being poured into its cavity. Im- mediately, however, that food is ingested and masti- cation commenced, a stimulus is furnished which ex- cites an abundant flow of secretion from the salivary glands. The drier the nature of the food, the longer is it delayed in the mouth, and the larger is the quan- tity of saliva required to convert it into a pulpy mass fit for being swallowed. The facilities offered by the salivary glands for the performance of experiments upon the subject of secre- tion have been lately taken advantage of by Bernard, 6 IXSALIYATION. and much light has thereby been thrown by this physiologist upon the matter. His investigations have shown that the flow of secretion from a gland is as much a phenomenon under the control of ner- vous action as muscular contraction. In the case of the submaxillary gland particularly, he has not only established in the most conclusive manner that the flow of its secretion takes place as the result of reflex nervous action, but has demonstrated the line of ner- vous continuit3^ through which the effect is produced. The saliva fulfils a variety of purposes in connec- tion with the digestive process. In the first place, by its presence in the mouth it aids the reduction of food b}^ mastication. By its moistening action, also, it further facilitates degluti- tion, the food being converted into a soft, pulpy mass in the mouth, which can be subsequently propelled with ease through the throat and gullet into the stomach. The assistance afforded by the saliva to both mastication and deglutition may be realized by picturing to the mind the condition that would exist, with dry food in the mouth, and no fluid secretion poured out to moisten it. The food having been thoroughly incorporated with a fluid before its arrival in the stomach, will be much more easily impregnated and attacked by the solvent secretion produced by this organ. Thus, insalivation in an evident manner aids gastric digestion. To gustation, insalivation contributes assistance by furnishing the means for fulfilling one of the essen- tial conditions required for the exercise of the sense. This special sense, of which the tongue forms the INSALIYATION. 37 seat, informs us of the sapid qualities of bodies re- ceived into the mouth, and so guides us in the selec- tion of food. For its exercise, contact and a state of solution form indispensable conditions. It is not only necessary that the substance to be tasted should be brought in contact with the surface endowed with sensibility, but that it should be in a state of solution, so that it may penetrate and reach the gustatory nerves. Now, the saliva contributes towards gusta- tion by supplying a medium for dissolving substances that are not already in a state of solution when intro- duced into the mouth; and should the substance hap- pen to be of such a nature as to resist solution, it will, as a consequence, be totally devoid of sapid properties. It is the opinion of Bernard, that the parotids are specially associated with the function of mastication; the submaxillary glands with that of gustation ; and the sublingual with that of deglutition. In support of this view, the parotid secretion is dis- tinguishable for its character of fluidity — a quality which specially fits it for the purpose suggested. It is also poured into the mouth in the neighborhood of the grinding teeth, or just where grinding action is carried on ; and, as shown by experiment upon the lower animals, and observation upon the human sub- ject in cases of salivary fistula — or where, as the re- sult of injury or disease, the parotid secretion finds an escape from its duct externally on to the cheek — its flow accompanies the process of mastication. In de- velopment, also, in the animal series, the parotids bear a relation to the state of perfection of the masti- catory apparatus. 38 INSALIVATION. It has been stated above that the flow of secretion from the parotid glands is observed to bear a relation to, or to take place contemporaneously with, the per- formance of mastication. The submaxillary glands respond, without any concurrence of mastication, to the simple application of a stimulus to the interior of the mouth. The impression derived from the con- tact of a stimulating agent with the surface of the tongue has been found, by experiment, to instantane- ously excite, through the medium of reflex nervous action, a flow of secretion from the submaxillary gland. The sight or even the idea of food, particu- larly in a hungry person, is sufficient to "make the mouth water;" and if attention be paid to the situa- tion where the fluid enters the mouth, it will be found to correspond with the point of termination of the submaxillary ducts, viz., underneath the anterior part of the tongue. The sublingual secretion, on account of its viscid consistence, is certainly well suited for besmearing the bolus of food about to be swallowed, with the view of facilitating its passage from the mouth to the stomach. As deglutition, also, is the finishing act of what is accomplished in the mouth, so the sublingual secretion has been experimentally found to be the last to make its appearance in respondence to a stim- ulus conveyed from the mouth. It is difficult, how- ever, to conceive how a secretion escaping in the position the sublingual does, can be specially applied to the exterior of the food at the back of the mouth as it is about to be swallowed. The actions that have been hitherto referred to INSALIVATION. 39 are of a physical nature; it may now be inquired whether the saliva exerts any chemical or digestive influence over either of the constituents of our food. The nitrogenized, oleaginous, and saccharine prin- ciples give no signs of being acted upon by it. Starch, however, is rapidly transformed, at least by our own saliva, into sugar. Using a decoction of starch, and supplying a temperature equal to that of the living body, the effect is so rapidly produced that a few moments only are required for sugar in quantity to make its appearance. Such is the nature of the transformative power with which both mixed saliva and the pure secretions from the salivary glands are endowed in the case of the human subject. The saliva of all animals, however, does not possess a simihar capacity. Neither the pure secretions from the different salivary glands, nor the admixture of these, in the case of the horse and dog, it may be mentioned, enjoy the power, when fresh, of transforming starch into sugar. It is true, after they have been kept a few days, that they enjoy it; but in this there is nothing special, the property being one that is common to organic fluids in general in a state of change. The mixed saliva of these animals, how- ever, that has been derived from the cavity of the mouth, is found to possess a transformative power, although of nothing like so strong a nature as that enjoyed by our own. The presence of an acid interferes with the opera- tion of the transformative endowment that has been just referred to, and the existence of a very small quantity is sufficient for the purpose. It follows, 40 INSALIYATION. therefore, that directly the food reaches the stomach and is brought in contact with its acid secretion, all action of saliva upon starch must cease. Now, such being the case, and the food being delayed so short a time as it is in the mouth, it is questionable if the attribute under consideration can be looked upon as being of any real physiological import. There are other secretions, as will be subsequently seen, belong- ing to the digestive apparatus, which enjoy in an energetic manner the power of digesting starch, or converting it into sugar; and with these other secre- tions, unlike as with saliva, the surrounding con- ditions happen to be in a high degree favorable to- wards the exercise of their power. DEGLUTITION. Deglutition constitutes the mechanical act by which the propulsion of the ingesta from the mouth into the stomach is effected. A canal exists for this purpose, consisting anatomically of two parts — the pharynx above, and the oesophagus, or gullet below. Deglutition is hence spoken of as pharyngeal and oesophageal, according to the part in operation. The pharynx, at least, the alimentary portion of it, forms a funnel-like cavity which receives the food from the mouth. It gradually tapers as it extends down to its junction with the oesophagus. It is lined with mucous membrane, and provided with muscular fibres so grouped and arranged as to have the effect, when in action, of urging what has been received from the mouth down into the oesophagus. The oesophagus forms a long, uniform, straight tube, which, beginning in the neck where the pharynx ends, passes just in front of the vertebral column down through the chest, to terminate in the abdomen by becoming continuous with the stomach. Its mu- cous coat is thrown into a number of longitudinal folds — an arrangement evidently intended to allow of distension of the canal during the passage of food. In this mucous coat are a quantity of little glands, • that pour out a secretion for the purpose of lubrica- 42 DEGLUTITION. ting the surface, and facilitating the accomj)lishment of deglutition. By muscular fibres arranged in two layers, one of which consists of a longitudinal, the other of a circular set, the tube is endowed with the power of performing a vermicular kind of movement, having the effect of exerting a propelling action to- wards the stomach. Although a canal of only moderate dimensions, the oesophagus is susceptible of dilatation, so as to allow surprisingly large bodies to pass through it. A Mr. Alexander Wood gave to one of the Dr. Munro's, of Edinburgh, a glass ball, three inches in circumference, which had been swallowed by a child two years old. It passed, it is said, through the alimentary canal in two days, and did not give rise to a bad symptom. Substances, however, sometimes get fixed in the oeso- phagus, and may call for surgical aid to push them on, or, may be, to effect their removal by the opera- tion of oesophagotomy. Pain, anxiety, and a sense of suffocation, are the symptoms produced by the lodg- ment of bodies in the oesophagus. The danger of ac- tual suffocation may render operative measures im- mediately necessary. Should this not be so, a little time may suffice, especially in the case of ordinary food, with the aid of the softening influence of the secretions poured out, to enable nature's unaided efforts to accomplish all that is required. False teeth form objects that sometimes get accidentally swal- lowed, and, from their complicated form, they may become so entangled in the throat as to render it ex- ceedingly difficult for the surgeon to effect their re- moval. DEGLUTITION. 43 A crossing of the food and air-passages takes place at the back of the mouth, which complicates the me- chanism belonging to the process of swallowing, on account of provision having to be made against the passage of food and fluids to the lungs instead of to the stomach. Advantages, however, of a more than commensurate nature are gained by the arrangement. In the first place, from the arrangement that exists, the expired column of air can be driven through the mouth and made subservient to the faculty of speech ; and in the next, odorous emanations can find their way from the mouth into the nostrils, so that the or- gan of smell may act conjointly with that of taste in producing an impression upon the sensorium. A large number of impressions, indeed, which are com- monly attributed to taste, are in reality chiefly due to smell — a fact that is rendered evident by chewing a piece of cinnamon, or some such aromatic substance, whilst the nose is held so as to prevent the passage of air into it from the mouth. The plan adopted by the nurse of holding the child's nose whilst nauseous medicine is being taken is evidently founded upon this circumstance. Common observation also suffi- ciently attests how much the sense of taste, as it is commonly understood, is blunted by the nasal mucous membrane being morbidly affected, as during the ex- istence of a cold. The means for preventing what is intended to reach the stomach from getting into the air-passages are very simple, and yet at the same time very effective. The act of swallowing, in itself, secures the protection of the air-passages. The material to be swallowed is 44 DEGLUTITION. first forced by the tongue to the back of the mouth. Here it excites, by reflex action, and, therefore, whe- ther the person is willing or not, the contraction of the muscles concerned in the accomplishment of the act. The tongue is carried backwards with what is to be swallowed resting upon its surface, whilst the larynx is raised close up underneath. By this the epiglottis is folded over the upper opening of the larynx, and the entrance to the air-passages thereby closed. The material is then shifted from the tongue directly down into the pharynx, behind and clear of the larynx. The epiglottis is doubtless specially provided for covering and protecting the opening of the larynx in the manner that has been described ; but Magendie's and Longet's experiments on its extirpation in the lower animals, and the cases that have been met with of its destruction by ulcerative disease in the human subject, show that its presence is not absolutely neces- sary, and that deglutition can be performed without it, without anything occurring particularly amiss. The tongue, in fact, being carried backwards, and folded as it is over the larynx, and this, at the same time, being raised close up underneath, affords the required protection. In the animals experimented on, it was only with the swallowing of liquids that any incon- venience arose. This excited a convulsive cough, which may be accounted for by a little fluid, that would have been intercepted by the presence of the epiglottis, trickling along from the surface of the tongue into the larjaix. A couple of membrano-muscular folds — the pos- DEGLUTITION. 45 terior pillars of the fauces — are provided at the back of the mouth for the purpose of preventing what is swallowed being forced up towards the nose. They stretch from the soft palate obliquely downwards and backwards, and can be drawn together like a couple of curtains^ so as to meet in the median line, and form a septum or partition between the upper — or nasal, and the lower — or alimentary part of the pharynx. As might be imagined, a loss of structural integrity in these parts, arising, for instance, from ulcerative disease — a state that forms a frequent concomitant of secondary syphilis — entails a defect in the power of preventing the passage of food and drink upwards into the nose. Persons so affected complain that, unless they swallow slowly and with the greatest care, such an event is very prone to occur. The act of pharyngeal deglutition forms a reflex- spinal phenomenon, and therefore requires no effort of the will to bring about its performance. Sub- stances reaching the back of the mouth, or arriving within the range of distribution of the incident nerves belonging to deglutition, produce an impression which acts upon the associated nervous centre — the medulla oblongata — and draws forth an impulse having the effect of throwing the muscles concerned into that state of action which results in the performance of the process. When the will is in abeyance, as during sleep, etc., deglutition is as effectively performed, on the requisite stimulus being supplied, as when consci- ousness and voluntary power exists ; and when the will is even operating in an adverse manner, if any- 46 DEGLUTITION. tiling can be made to reach the back of the mouth, it must, nolens volens, be swallowed. Although essentially a reflex-spinal act, and there- fore taking j)lace without the agency of, and even may be, as just remarked, in opposition to the will, yet the will has power, within certain limits, of ex- citing its performance. We are all conscious of pos- sessing the power, by an exercise of the will, of per- forming the act of swallowing without there being any food or drink in the mouth to swallow, and with- out even, it will be found, if attention be given to the point, using our saliva instead for furnishing a physi- cal stimulus to the parts. A few repetitions of the act, if continued in rapid succession, is, however, all that can be effected through the exercise of the will ; the parts becoming then fatigued and refusing to re- spond to the call that may be made upon them. With the stimulus of foreign matter, on the other hand, to act, as in swallowing in the ordinary way, degluti- tion may be rapidly repeated over and over again without the slightest difficulty or sense of fatigue be- ing experienced. Every-day experience shows that when all the parts belonging to deglutition are in a state of structural and functional integrity, the security our air-passages enjoy from the intrusion of foreign matter is exceed- ingly complete; and it is well for our safety that it is so. It is true, it has sometimes happened, through the parts being taken as it were by surprise, that foreign bodies, as pieces of coin and so on, have dropped down towards the lungs ; and the most seri- ous consequences have in some cases arisen there- DEGLUTITION. 47 from. The convulsive paroxysm of coughing which is sometimes brought on at the meal-table by '^ some- thing going the wrong way," is usually, if not almost invariably, attributable to an attempt of laughing, coughing, or talking being made whilst there is food or fluid in the mouth. By the effort at inspiration, a small portion of food (a light crumb of bread is a particularly favorable substance for the purpose), or a little fluid shall happen to be drawn into the air- passages, or against the laryngeal surface of the epi- glottis; and, although it may be immediately after- w^ards expelled, an urgent state of temporary discom- posure is the result, on account of the exquisite sen- sibility with which the surface touched is endowed. Should the energy of the nervous system have be- come blunted, as it is observed to do under approach- ing death, an impression upon the fauces may fail to excite that quick and perfect respondence of the mus- cles of deglutition which is required for the insurance of our personal safety. Thus, a portion of what has been introduced into the mouth may chance to get into the respiratory passages, and excite a fit of chok- ing which is sufficient to extinguish the flickering spark of life. Persons, it should be remembered, in a dying state swallow but imperfectly; and, therefore, the utmost caution is required in giving them medi- cine and drink, lest a sudden issue be brought about by something that is being administered passing the wrong way. DIFFICULTY OF SWALLOWING, OR DYSPHAGIA. Although the object attained by the process of de- glutition is an exceedingly simple one — namely, the transit of our food and drink from the mouth to the stomach — yet difficulties connected with its perform- ance are not of uncommon occurrence, and these dif- ficulties in some cases give rise to the most urgent and serious consequences. Dysphagia is the term applied to difficult deglutition ; aphagia, when the condition amounts to an impossibility of swallowing. The seat of complaint may be located in the mouth, fauces, pharynx, or oesophagus ; and the obstruction may be either partial or complete, and temporary or permanent. A permanent and complete obstruction cannot be long before it leads to death by inanition, unless, by operative means, an opening can be estab- lished direct into the stomach through which the sus- tenance required can be received. A variety of causes contribute to the production of dysphagia. They may be divided into mechanical and dynamic. The mechanical causes are such as congenital malformations of the mouth, throat, and oesophagus ; inflammation of or structural changes in the tongue, fauces, pharynx, larynx, and epiglottis, and oesopha- gus ; obstruction of the passage by the projection of a DYSPHAGIA. 49 tumor, or the presence of a foreign body within ; and its occhision by pressure from without, as from the existence of a tumor, abscess, or aneurism in the neighborhood. Malignant disease, and the contraction following inflammatory action, produced by swallowing a cor- rosive material, constitute, it may be said, the most common causes of mechanical dysphagia. A remarkable case of obstruction of the passage by a growth projecting within is mentioned by Monro.^ A polypoid excrescence grew from the upper part of the oesophagus, and extended down within the canal to the orifice of the stomach. On vomiting being ex- cited, this growth was thrown up into the mouth, and reached as far as the front teeth ; but it could hardly be retained for half a minute in this position, on ac- count of the opening of the larynx being covered by it, and the breathing thereby stopped. In the dynamic form of dj^sphagia, a perverted ac- tion — spasm or paralysis — of some portion or other of the muscular apparatus belonging to deglutition, constitutes the immediate source of the disorder. The perverted action, however, is dependent on a variety of pathological states, which may be either local or remote, as will be seen from what follows. Difficulty of swallowing is one of the phenomena of hydrophobia and tetanus. Here the dysphagia de- pends upon a morbid functional condition of the ner- vous apparatus. Such a state of irritability exists. ^ " The Morbid Anatomy of the Human Gullet, Stomach, and In- testmes," by Alex. Monro, M.D., Edinburgh, 1811. 4 50 DYSPHAGIA. that an impression, which, under natural circum- stances, would have led to an ordinary performance of the act of swallowing, throws the muscles, instead, into a violent and continued state of spasmodic con- traction. In structural disease of the medulla oblongata, the centre presiding over deglutition, as well as in struc- tural disease of the neighboring parts — whether con- sisting of central nervous matter, the enveloping membranes, or bone — more or less irregularity in the performance of swallowing may be looked for as a concomitant ; and the occurrence of this symptom, in conjunction with other evidence of such disease existing, must be regarded as in the highest degree ominous of danger. Besides other modes of unfavor- able termination, a patient so affected is under daily risk of being choked by a morsel of food becoming impacted in the throat from the imperfect manner in which deglutition is performed. A patient, for in- stance — to give a sketch from an actual case — shall be complaining of symptoms suggestive of disease about the base of the brain. An occasional difficulty in the proper performance of swallowing, an altera- tion of the voice, and some disturbance of the breath- ing, lead to the presumption that the medulla oblon- gata is in some way or other implicated. The pa- tient is sitting at dinner, and is all of a sudden seized with a fit of suffocation, and dies before there is time for professional aid to be procured. At the post-mor- tem examination, a piece of meat is found lodged in the entrance to the larynx, and this by stopping the breathing has been the immediate cause of death. DYSPHAGIA. 51 Cerebral disease is also found sufficient to account for the phenomena that transpired. In a case that not long since fell under my obser- vation, a paralyzed condition of the muscles of the fauces, apparently resulting from cold, formed the cause of a temporary defect in the power of properly performing the act of swallowing. The patient spoke in a guttural manner, and complained that when he swallowed liquids, unless he exercised great care in swallowing slowly, a portion got into and partly re- turned through his nose, thereby occasioning him great inconvenience. The case at first sight ap- peared like one of structural loss of the soft palate from ulcerative disease. On looking into the mouth, all the parts were found in a state of structural integ- rity; but the soft palate hung down from the roof in a flaccid manner, floating to and fro with the breath. Under a tonic treatment, a week or two's time suf- ficed to restore both voice and deglutition to their natural state. Dysphagia from a paralyzed state of the muscles of the fauces and pharj^nx sometimes comes on as one of the sequelre of diphtheria. After a variable period of temporary convalescence from the primary affection, the patient begins to experience difficulty in swallowing, accompanied with an alteration of the voice. These phenomena are associated with loss of sensibility in the soft palate, and are followed by manifestations of unpaired nervous power elsewhere. It has been suggested that these symptoms of paraly- sis consequent upon diphtheria are due to a peripheral alteration of the nerves of the primarily aflected part. 52 DYSPHAGIA. the effect of wliicli is propagated to the spinal centre in the same sort of way as happens in the case of a wound that produces tetanus, and thence occasions by a reflected influence the train of phenomena that are observed. The oesophagus may form the seat of affection in dysphagia arising from both spasm and paralysis. Dr. Monro^ records a striking and well-authenticated case of dysphagia arising from spasmodic stricture of the oesophagus. The patient, a man 45 years of age, had been the subject of occasional fits of dyspepsia. At first he only experienced an occasional slight diffi- culty in swallowing, attended with pain about the middle of the sternum. At breakfast one day he observed, on attempting to swallow some bread with his tea, that it stopped in his gullet for a few seconds. A rumbling noise, as if from the discharge of wind, was then heard, and immediately afterwards the food passed on into the stomach. A probang being in- troduced, its progress was stopped when about half- way down the oesophagus, and with a large bougie a stricture was distinctly felt. Relief was obtained; but after an attack of quinsy, which subsequently arose from exposure to cold, the dysphagia returned, and it was found impossible to introduce even the smallest instrument. His symptoms, however, in the course of a few days, remitted, and the probang passed as before. Evidence of gastric disease then showed itself, and in a few months' time the patient died. Ulcerative disease was found in the stomach, ]jut its ' Op. cit. DYSPHAGIA. 53 cardiac orifice was perfectly free, and not the slightest sign of structural mischief was to be discovered in any part of the oesophagus. Dysphagia from spasm of the oesophagus is distin- guished from dysphagia, the result of organic disease, by its mode of accession, which is more or less sudden, and by the remissions which frequently occur. In dysphagia from organic constriction, the invasion is slow, and the diliiculty steadily increases. Still, it must be borne in mind that the existence of organic disease often excites more or less spasmodic contrac- tion, and thus partial remissions may be observed in the case. When the spasm affects the upper part of the tube, attempts at swallowing are quite or nearly quite in- effectual, the substances taken being at once rejected. When, on the other hand, it occurs in the lower part, swalloAving may be apparently accomplished by the upper part yielding, and retaining for a while what has been taken. Under such circumstances, however, great distress is experienced until the substance has either passed on or been rejected. A case quoted by Monro shows the extent of yielding in the upper part of the oesophagus that may thus take place from con- striction of the passages below. The case Avas one of organic constriction, and therefore the obstruction was of a constant or permanent nature. The capacity for yielding became such, that the patient could re- tain nearly a pint of nutritious liquid, consisting of eggs, milk, and sugar, for ten minutes, conversing with his friends during the while. The form of dysphagia now under consideration is 54 DYSPHAGIA. attended with pain behind the sternum, which is very much aggravated by attempts at swallowing. The sensation complained of may be that of soreness or a sense of cord-like tightness behind the sternum or be- tween the scapula, a dull pain referred to the course of the oesophagus, or of an impression as of a foreign substance lodged within it. It is especially in the hysterical and hypochondriacal dispositions that this spasmodic affection occurs, and various are the excit- ing causes that lead to its development. In the globus liystericus which forms so frequent a concomitant of hysteria, a reversed spasmodic action of the oesopha- gus may be looked upon as constituting the cause of what is felt. Instead of spasm, dysphagia may result from para- lysis of the oesophagus. The distinguishing features belonging to this form of dysphagia are, that small cjuantities of a substance may be swallowed with greater facility than large, and that the probang can be passed without obstruction into the stomach. Paralysis of the oesophagus constitutes one of the phenomena produced by division of the pneumogastric nerves in the neck. In one of my own experiments, where this operation had been performed upon a dog in connection with another object, I was surprised to find that a quantity of bread and milk placed before it was afterwards devoured, and seemed to be prop- erly swallowed. On examining the animal, however, after the destruction of life a few hours afterwards, a large swelling was found at the back of the chest, which consisted of the oesophagus distended with the bread and milk. The division had not been high DYSPHAGIA. 65 enough up to affect the pharyngeal muscles, and so pharyngeal deglutition could be performed. The paralyzed oesophagus had yielded, as the successive portions reached it, like a flaccid bag. In the treatment of dysphagia, the practitioner must be guided by the nature of the cause upon which the affection depends. Dysphagia arising from organic constriction is of the gravest possible import, and leaves but little room for hope. In the spasmodic variety, attention should be given to the removal of any extraneous source of irritation or debilitating influence that may be discovered. Sir B. Brodie relieved a female, who for three years had been subject to dysphagia to an extent that prevented her from being able to swallow solids, and liquids only with great difiiculty, by the removal of some internal hoemorrhoidal tumors, which, from to time, had caused considerable hemorrhage. The general means to be tried consist of cathartic, sedative, and antispasmodic enem^ata; and mild aperients, seda- tives, and antispasmodics administered by the mouth; combined with or followed by a course of tonics. Swallowing cold or iced fluids slowly will sometimes overcome spasm. Should these measures fail, the occasional passage of a bougie should receive a trial. In the paralytic variety, cases are recorded by Monro in which relief was obtained by the use of electricity. Should the employment of the probang or bougie be resorted to, whether as a measure of treatment or of diagnosis, the utmost caution requires to be exer- 56 DYSPnAGIA. cised in the process of introduction. Abercrombie mentions a case that was related to him in which the passage of a probang for dysphagia, under the idea of its being caused by stricture of the oesopha- gus, caused the rupture of an aneurism and ahiiost instantaneous death. In another case, also men- tioned by him, the probang ruptured an abscess, and led to the escape of an immense quantity of matter, which afforded immediate and permanent relief. The nature of the case in this complaint may be such, that, for sustaining the patient, nutrient en- emata require to be had recourse to. Where organic constriction is the cause of the dysphagia, and espe- cially when the disease is of a non-malignant charac- ter, as particularly in the constriction resulting from the swallowing of a corrosive agent, the question of making an artificial opening into the stomach for the introduction of food may be entertained and put before the patient, all other measures having failed in affording relief, and death from starvation being the onlj^ prospect without the operation. GASTRIC DIGESTION. The stomach constitutes that part of the digestive apparatus in which the food undergoes the most marked change that occurs throughout the digestive process. The effect of gastric digestion is to dissolve and chemically transform certain principles of our aliment, and to reduce the mass of food to a semi- liquid condition, it being when so reduced spoken of as constituting chyme. The organ in which this process takes place is an elongated pouch-like receptacle formed by a dilata- tion of the alimentary tract immediately below the oesophagus. It is placed in the upper part of the abdominal cavity, and extends across from the left side, at which the oesophagus enters it, to the right, where it terminates in the duodenum, or first portion of the small intestine. A constricted orifice, sur- rounded by a band of sphincter fibres — the pyloric valve — separates the two, and, under natural circum- stances, allows only digested or semi-fluid matter to pass. A few sphincter fibres also exist around the other or cardiac orifice of the stomach, and serve by their contraction, whilst chymification is going on, to prevent the* reflux of food into the gullet. Belonging to the coats of the stomach is a layer of muscular fibres of the simple or unstriped kind, 58 GASTRIC DIGESTION. which spread in certain different directions over the organ. The action of these muscular fibres is, by a slow vermicular kind of movement, to produce an orderly circulation of the food in the cavity of the stomach. The muscular coat thus aids in the reduction of food by promoting its admixture with the solvent secretion poured out from the glandular follicles be- longing to the mucous coat. Through the friction also to Avhicli the fragments of food are subjected by the movement performed, their superficial portion is removed as fast as it is softened by digestion, and so the portion below is progressively exposed until a disappearance of the fragment results. The circular fibres towards the pyloric extremity of the stomach, which form the most developed por- tion of the muscular coat, and constitute a layer of very great thickness in the stomach of the pig, may be regarded, it seems to me, as specially intended for exerting a compressing action that shall have the ef- fect of squeezing out from the digesting mass its fluid or digested part, this being permitted to pass through the pylorus, whilst the solid or non-digested portion continues to be returned till the process is complete. The innermost or mucous coat is the most import- ant of all the tunics of the stomach ; for it is to this that the characteristic attribute of the stomach is owing, it being here that the glandular apparatus is situated which gives to the organ the solvent power it enjoys. When the stomach is empy, the mucous membrane, which is then in a loose state, is thrown into a number of rugose folds, that are observed to take more or less of a londtudinal course. These THE STOMACH. 59 are the rugae of the stomach, and, being only inflec- tions caused by the contraction of the muscular coat, they become entirely obliterated when the organ is in a distended state. The mucous membrane forms a thickish layer of a soft though compact consistence. Its color varies according as the organ is in a state of functional quiescence or activity. In the former it is of a pale pink, whilst in the latter it deepens to a bright reddish hue from the increased vascularity that exists. The mucous membrane of the stomach, like other mucous membranes, structurally consists of a super- ficial epithelial layer, the cells of which are of the columnar-shaped variety, and a deeper part called chorion, which is made up of two layers — a layer of basement membrane above supporting the epithelium, and fibro-vascular tissue beneath. It is in the sub- stance of the chorion that the glandular apparatus belonging to the stomach is placed. It has been somewhat recently discovered that some muscular element enters into the composition of the deeper stratum of the mucous membrane. This is quite independent of the layer of muscular fibres forming one of the tunics of the organ. The use suggested that the muscular element fulfils in this situation is to empty the glandular tubules of their secretion. The apparatus for the production of the gastric juice consists of a multitude of little simple glandular tubes, called the gastric follicles. They dip doAvn vertically into the mucous membrane, and are packed closely together side by side. When the free surface GO GASTRIC DIGESTION. of the mucous membrane immersed under water is examined with a low magnifying power by reflected lidit, it is seen to be everywhere marked with more or less circular openings. These are the orifices of the gastric follicles. They give to the surface a sieve-like appearance. The intervening ridges con- tain a rich plexus of capillary bloodvessels, which in an injected specimen are found to map out the surface in a very orderly manner. Towards the pyloric end of the stomach, these ridges send up little projecting processes, that may almost be compared in appear- ance to rudimentary villi. The gastric follicles consist of simple tubular invo- lutions of basement membrane lined with epithelium. The leno'th of the tubes is on an average about the 2^5 th part of an inch; their diameter about the sioth of an inch. Their length and breadth are greater at the pyloric than at the cardiac end of the organ. Below, they terminate in rounded and slightly en- larged closed extremities. It is difficult, however, to say if all the tubules present this simple termination. There is often a pouch-like disposition observable at the lower extremity of a tube ; or, sometimes an ap- pearance of a tube subdividing into two or three ter- minal extremities. It is possible that these appear- ances may be illusory, and in reality due to the effect of manipulation or chance superposition of tubules. The gastric follicles are imbedded in a matrix of areolar tissue and the muscular element referred to, and are closely surrounded by bloodvessels, which form a plexus around them, in coursing upwards be- tween them to the capillaries at the surface. THE STOMACH. 61 Towards the free extremity, the gastric tubule is lined with the same kind of epithelium as that which covers the surface of the stomach, viz., the columnar- shaped variety. Lower down, the epithelium is of the glandular kind, the cells being more or less round or spheroidal in sliape. These follicles, looked at individually, may from their minuteness appear insignificant; but directly the immense number of them that exists is taken into account, a proper idea of their significance is obtained. By counting the number of orifices existing in a given space, and reckoning for the whole extent of surfirce presented by the mucous lining of the stomach, it has been computed by Sappey that there are upwards of five millions of follicles in an average-sized human stomach. The anatomical arrangement that has been de- scribed is the one which recent observation has dis- closed as belonging to the human stomach. It does not agree, however, with the description that used to be given, which was drawn from the condition exist- ing in the dog, where the internal surface is marked all over with irregularly hexagonal-shaped pits or depressions known by the name of the gastric alveoli. These gastric alveoli met with in the dog are lined, like the surface of the stomach, with columnar epi- thelium, and are usually found filled with mucus. It is into the bottom of them that the gastric follicles open, there being clusters of about four or five be- longing to each. Besides the open glandular tubules that have been referred to, closed sacs, corresponding in character, 62 GASTRIC DIGESTION. situation, and contents with tlie solitary glands of the intestine, are frequently to be recognized. It ap- pears that the}^ are not invariably present; at all events, it is not always possible to find them. When present, they are scattered more or less completely throughout the stomach, but are most numerous at its pyloric end. They are more frequently to be found in the stomachs of infants and children than in those of grown-up persons. Nothing is known wath regard to the purpose fulfilled by their presence. The stomach is an exceedingly vascular organ. One of the three divisions of the coeliac axis is spe- cially set apart for distribution to it, and a further supply of blood is given to it from each of the other two divisions. The capillaries of the mucous membrane are de- rived from the ramifications into which the arteries split up in the submucous tunic, or the layer of areo- lar tissue existing between the mucous and muscular coats. Capillaries proceeding from these ramifica- tions enter the mucous membrane below, and run up between the secreting tubules, around Avhich they form a plexus, towards its free surface. Arrived at the surface, these intertubular capillaries, instead of at once throwing themselves into veins, give origin to the much closer and more capacious set of superfi- cial capillaries which map out and surround the ori- fices of the gastric tubules. From this latter set, veins arise and pass down between the tubules. This disposition of the intertubular and superficial sets of capillaries of the stomach I believe to contribute to- wards the security of the organ from self-digestion, in NATURE OF THE PROCESS. 63 a manner that I shall subsequently point out when referring to the means by which I consider the stom- ach is enabled to resist undergoing digestion itself during the progress of digestion in its interior. The veins which collect the blood that has trav- ersed the stomach form a part of the portal system. The blood, therefore, returning from the stomach, is transmitted to and passes through the liver before it reaches the systemic veins. A nervous supply is given to the stomach from both the cerebro-spinal and sympathetic systems. Branches are distributed to it from the pneumogas- trics ; and filaments derived from the large ganglia situated in front of the vertebral column, forming the sympathetic centre connected with the chylopoietic organs, reach it by coursing in an intricate plexiform manner along its arteries. Experiment shows that the muscular coat is un- questionably susceptible of being influenced by im- pressions travelling along the pneumogastrics. Sec- tion of these nerves provokes vomiting, if food is contained in the stomach at the time of the opera- tion ; and their galvanic irritation in the recently killed animal visibly throws the stomach into an excited state of movement. It has formed a debated point, whether or not sec- tion of the pneumogastrics stops the secretion of gastric juice. It seems that at first the process of secretion is interfered with ; but it is evident, beyond all dispute, that gastric juice must be afterwards se- creted ; for it has been found that digestion can be 64 CxASTRIC DIGESTIOX. subsequently carried on, although, it is true, with less energy than under natural circumstances. Little or nothing of a positive nature has been as- certained about the influence exerted by the sympa- thetic upon digestion and the stomach ; but it may be premised that it is in an important manner con- nected with the process of secretion. The most erroneous ideas formerly prevailed about the nature of gastric digestion. Reaumur and Spallan- zani were the first to show that the reduction of food in the stomach is due to the influence of a solvent fluid poured out from the walls of the organ. These experimentalists caused animals to swallow perforated metal tubes and balls containing food, and found that the food, notwithstanding its position, underwent di- gestion and was removed. They also introduced pieces of sponge in their perforated tubes and balls ; and on withdrawing them, after they had been in the stomach a little while, by means of a string attached, they obtained some of the gastric secretion. This they experimented with, and found that they could get digestion performed outside the stomach. Spallan- zani further experimented upon himself. Swallow- ing some small perforated wooden tubes containing food, he afterwards excited vomiting, and was enabled to observe the effects that had been produced by his own gastric juice. By these experiments, the prevalent notion of the day — namel}^, that digestion depended upon a com- pressing action exerted by the muscular fibres of the stomach — was dispersed. The reduction of food in .the stomach has been hitherto looked upon as effected NATURE OF THE PROCESS. 65 by a process analogous to that by which reduction is accomplished in the gizzard of the bird. The gizzard, however, is not the homologue of a stomach : it is simply a triturating and not a digesting organ, and occupies in reality the place of the masticating appa- ratus of the mammal. For much of the information we possess regarding the precise phenomena of digestion, we are indebted originally to the advantage that was taken of a rare opportunity that presented itself of watching what occurred in the interior of the living stomach of an individual who had met with a gunshot accident that left a permanent opening leading direct from the sur- face into the cavity of the organ. Since the occur- rence of this case, an artificial opening has been made into the stomachs of the lower animals, and experi- ments tliereby performed which have confirmed and extended the knowledge previously obtained. Alexis St. Martin is the name of the person re- ferred to, whose case furnished the opportunity, which was taken advantage of by Dr. Beaumont, a surgeon in the United States Army, for conducting the re- searches from which issued the first complete account of the process of gastric digestion. In June, 1822, Alexis St. Martin, a Canadian by birth, and at the time about eighteen years of age, received a charge of duck-shot in his left side, from the accidental discharge of a gun, the muzzle of which was not more than a yard off. The charge entered his side from behind, and passed in an oblique direc- tion forwards and inwards, — "literally," it is stated, " blovvdng off integuments and muscles of the size of 6G GASTRIC DIGESTION. a man's hand, fracturing and carrying away the ante- rior half of the sixth rib, fracturing the fifth, lacera- ting the lower portion of the left lobe of the lungs and the diaphragm, and perforating the stomach." From this extensive injury the young Canadian, miraculously enough, soon became restored to a per- fect state of health. The wound healed, with the ex- ception of tlie opening made into the stomach, which resisted every measure to close it. A compress and bandage had at first to be applied to retain the food in the stomach ; but afterwards a fold of mucous membrane came down into the opening, which, in a valvular manner, closed it from above, so as to dis- pense with the necessity of any external appliance to prevent the escape of what had been taken. " This valvular formation," says Beaumont, "adapted itself to the accidental orifice so as completely to prevent the efflux of the gastric contents when the stomach was full, but was easily depressed with the finger." Such was the case upon which Dr. Beaumont's ex- periments and observations on digestion were per- formed. Commencing in 1825, his investigations were continued, with intervals of interruption, till the publication of his work, "On the Gastric Juice and the Physiology of Digestion," in 1833. To obtain gastric juice. Dr. Beaumont introduced a gum-elastic catheter for a distance of Rve or six inches into tlie empty stomach. The presence of the catheter excited a flow of secretion from the glandular follicles, and soon it began to escape through the catheter. At first it issued in drops, but afterwards in an inter- rupted, or sometimes a continuous, stream. Moving NATURE OF THE PROCESS. 67 the catheter about in the stomach increased the ra- pidity of the flow. The quantity of gastric juice or- dinarily obtained at the time was from four drachms to one and a half or two ounces. Its extraction was generally accompanied with the peculiar sensation known as sinking at the pit of the stomach, and with some degree of faintness, which rendered it necessary to stop the operation. That the stomach and health of Alexis St. Martin did not suffer under the experi- ments performed, is shown by the statement that the last series was continued for four months; and that, although different objects, such as food, drinks, gas- tric juice, chyme, elastic catheters, thermometer tubes, etc., were being introduced or taken out almost daily, and sometimes hourly, he continued during the time unusually plethoric and robust. Another case of a similar description to that of St. Martin has since occurred, and been made the sub- ject of research by Bidder and Schmidt. Their ex- periments were continued for a period of about eight weeks. The subject of this case was a woman, in good health, who had had the unnatural opening in the stomach for about three years. The case of Alexis St. Martin, and the fruitful ac- count to which it was turned by Dr. Beaumont, doubt- less suggested to physiologists the designed production of gastric fistula in the lower animals. Bassow, in Russia, and Blondlot, in France, applied themselves about the same time, and evidently independently of, or unknowingly to each other, to the subject, and succeeded in establishing a gastric fistula in the dog. The operation has since been successfully repeated 68 GASTRIC DIGESTION. by various pbj'siologists. I have myself taken avail of the means afforded by it for personally verifying what is about to be said regarding the phenomena of gastric digestion. It may now, then, be definitely asserted that gas- tric digestion is effected by the solvent agency of a secretion poured out by the glandular follicles that exist in the walls of the stomach. To the properties of this secretion I will first proceed to direct attention. Gastric j uice, separated from the mucus with which it is mixed, as obtained from the stomach, is a lim- pid, transparent, and almost colorless liquid. It pos- sesses a strongly acid with a slightly saline taste, and a faint peculiar odor which varies in character in different animals. Its specific gravity is very little above that of water. When pure, it occupies a re- markable position as an animal fluid in its power of resisting putrefactive decomposition. It may also be kept for a great length of time without losing its characteristic physiological properties. Not only does it resist decomposition itself, but it further acts as an antiseptic agent upon other bodies, checking the pu- trefactive process, when this has commenced, in sub- stances submitted to its influence. Its special physi- ological attribute is the power it possesses of dissolv- ing the nitrogenized principles of our food ; and for the enjoyment of this power investigation has shown that two ingredients, an acid and the organic princi- ple called pepsin, form the agents essentially re- quired. Neither of these will act alone ; but, com- bined, they supply all that is wanted for the produc- tion of a solvent or digestive menstruum. PEPSIN. 69 Pepsin constitutes a peculiar nitrogenized organic principle, yielded only by the mucous membrane of the stomach. It is soluble in water, but insoluble in spirit. Its aqueous solution, unlike one of albu- men, is not coagulated by heat ; but by exposure to a temperature above 140° the active properties of pepsin are destroyed, and it is reduced to a com- pletely inert substance. It possesses by itself the power of curdling milk — a power that is enjoyed by no other neutral organic principle. This property is turned to practical account in the uses to which runnet — an article procured from the fourth stomach of the calf, and owing its virtue to pepsin — is applied. It is to be noted that pepsin is always present in the mucous membrane of the stomach ; not only, therefore, whilst digestion is going on, but during fasting, and even under the severest forms of disease. I have found it apparently as abundant and effective in the stomach of the dog after seventy-two hours' fast- ing, as at a period of digestion. I have also found that the acidulated infusion of the mucous membrane of stomachs taken from the post-mortem room of Guy's Hospital, and derived from persons who had died from protracted disease, has possessed energetic digestive properties. With the stomachs that were examined, the following, for example, were the causes of death : Typhoid fever, phthisis, apoplexy, larda- ceous disease, lithotomy, ovarian disease, and heart disease with typhoid symptoms. Pepsin procured from the stomach of the calf and pig has an extensive sale as a medicinal agent, being administered in dyspepsia and some other complaints. 70 GASTRIC DIGESTION. with the view of contributing assistance towards the performance of digestion. Seeing that pepsin hap- pens to be always present in the mucous layer at the surface of the stomach, doubts may not unreasonably be entertained regarding the utility of, or the reality of any assistance to be derived from its administra- tion. It may be admitted, however, as possible that in some cases the pepsin in the stomach may be de- ficient in quantity or defective in quality, and that service may be derived from its administration with the food; but for this to be the case, it stands to rea- son that the pepsin employed must be in an effective condition. Now, speaking from the examination of several specimens of pepsin procured from some of the largest pharmaceutical establishments in London, the bulk of that which is sold is totally devoid of any active property. Whether this arises from too much heat having been employed in its preparation, or from whatever cause, the fact remains that the chief por- tion of the pepsin sold and administered, being per- fectly inert as a digestive principle, is destitute of any real value as an agent for affording assistance towards the performance of digestion.^ Whatever benefit, therefore, has seemed to accrue from the em- ployment of such a preparation, must have arisen from its influence on the mind rather than on the process of digestion. One of the most striking characters of the gastric juice is its strong acidity. The nature of the acid ' In the " Gulstonian Lectures," vide "Lancet," April 25th, 1863, I mentioned the sources from whence I obtained the specimens of pepsin referred to. It is but justice to state that Messrs. Bullock & Keynolds's pig pepsin was found to possess very active properties. THE GASTRIC JUICE. 71 has been variously stated by different authorities. Dr. Prout, who was the first to investigate the sub- ject, arrived at the conclusion that the gastric juice contained a considerable quantity of free hydrochloric acid. Blondlot objected to Prout's method of anal- ysis, and himself contended that the acidity is due, not to the existence of a free acid, but to an acid phosphate of lime. Tiedemann and Gmelin say that they have encountered the acetic and butyric acids. Some modern authorities have assigned the acidity to the presence of lactic acid. It is not im- possible that these discordant statements may owe their origin to the gastric juice of different animals having been taken for examination. Altogether, the weight of opinion is in favor of the hydrochloric as being the acid which belongs to the gastric juice of the human subject. To account, however, for certain traits of behavior that have been noticed, it has been suggested that the acid does not exist in a free state, but in combination with pepsin, which modifies its properties, and makes it in fact a new acid, to which the name of hydrochloro-pepsic acid has been given. Mean composition, from nine analyses, of gastric juice from the dog, free from admixture with saliva (Schmidt). Water, 973.062 Organic matter. 17.127 Free hydrochloric acid, . 3.050 Chloride of potassium, 1.125 Chloride of sodium, . 2.507 Chloride of calcium, 0.624 Hydrochlorate of ammonia. 0.468 Phosphate of lime, . . . . 1.729 Phosphate of magnesia, . 0.226 Phosphate of iron, . 0.082 1000.000 72 GASTRIC DIGESTION. It is onl}^ at the period when gastric juice is re- quired in the stomach, namely, whilst food is present to be digested, that it flows from the glandular fol- licles. During the empty state of the organ, its sur- face is besmeared with a transparent viscid mucus, which, with some frothy saliva that has descended from the mouth, constitutes its only contents. Test- paper applied may indicate a neutral or even an alkaline reaction. Immediately, however, that food is ingested, or any foreign body introduced, a stimulus is supplied which causes the mucous membrane to become turgid, and more or less reddened from in- creased vascularity. Little limpid drops of fluid then exude from the surface like drops of perspiration from the skin. These limpid drops constitute the product of secretion of the glandular follicles. On being tested, they are invariably found to present a stronalv acid reaction. Formerly, the gastric juice was described as being sometimes acid, sometimes alkaline. It is evident, however, that the mucus which the stomach contains during its quiescent state must have been mistaken for the special gastric secretion which is present only when digestion is going on, and which, as mentioned above, is invariably very strongly acid. Observation has shown that the substance intro- duced into the stomach need not necessarily form an alimentary material to excite a flow of gastric juice from the follicles. The contact of a foreign substance of any description with the mucous surface, aiFords the requisite stimulus for exciting secretion. The presence of the gum-elastic catheter in Dr. Beaumont's THE GASTRIC JUICE. 73 experiments formed a sufficient stimulus, and enabled him to draw off, as he did, pure gastric juice from Alexis St. Martin's stomach. The quantity of gastric juice secreted cannot be looked upon as having been as yet even approxi- matively determined, but there is no doubt that it is large. According to Tiedemann and Gmelin, it varies with the stimulating character and digestibility of the articles of food ingested. The more difficult of digestion an alimentary substance, the larger the quantity of gastric juice that is poured out. Liquid food does not exert the same stimulating effect upon secretion as solid. It is said that alkaline materials excite in a special manner the flow of gastric juice; and that it seems, on the other hand, to be diminished by acids. According to Corvisart, ice, very cold water, moderately strong alcoholic liquids, wines (especially Sherry and Bordeaux), strong coffee, and various aro- matic and bitter vegetable infusions, excite with more or less energy the secretion of a liquid possessing a high degree of digestive power. In a febrile state of the system, as ascertained by Dr. Beaumont upon Alexis St. Martin, the secre- tion of gastric juice becomes greatly diminished or entirely suppressed. To quote Dr. Beaumont's words, "Drinks received are immediately absorbed, or otherwise disposed of, none remaining in the stomach ten minutes after being swallowed. Food taken in this condition of the stomach remains undigested for twenty-four or forty-eight hours, or more, increasing the derangement of the whole alimentary canal, and aggravating the general symptoms of disease." Such, 74 GASTRIC DIGESTION". it is well known, harmonizes with the dictates afforded by the inclinations experienced, there being in the febrile state a repugnance for solid food, with a strong craving after liquids. The mistake of administering solid food in such a state is apparent. Should it, in- deed, be taken, and vomiting, which is generally ex- cited as a consequence, not happen to follow, it will remain as a load upon the stomach, and so form a source of irritation to the system. Eberle was the first to obtain the clue that led to the discovery of the acting principles belonging to the gastric juice. Having ascertained that neither an acid nor an infusion of the mucous membrane of the stomach possessed any digestive power, he placed the two together, and immediately obtained a digestive or solvent menstruum. It is only the mucous mem- brane of the stomach that will yield the organic matter required, but any acid — mineral or organic — will serve for giving to the proper infusion digestive properties. Gastric juice may thus be artificially prepared, all that is requisite being to combine the special organic principle belonging to the mucous membrane of the stomach — pepsin — with an acid. For making arti- ficial gastric juice, either prepared pepsin or the fresh or dried stomach may be used. If the prepared pep- sin of the shops be employed, attention must be given to its being in an effective state ; for, as already men- tioned, the bulk of the pepsin sold is a perfectly inert and worthless material. Of good pepsin, ten grains to the ounce of water forms a sufiicient quantity to 23roduce an energetic digestive solution with the re- ARTIFICIAL DIGESTION. 75 quisite addition of acid. If the fresh stomach be taken, the pulp scraped off from the mucous surface, or the mucous membrane itself cut off in pieces, must be infused in cold or tepid water for from twelve to twenty-four hours. The strained infusion is then to be treated with the acid, and an artificial digestive liquid is obtained. The properly dried mucous membrane answers just as well for making the infusion as that of the recent stomach, and it has the advantage of keeping, so as to be ready for use at any time. I am in the habit of preserving and employing it for experimental illus- tration in my course of physiological lectures, and the following is the way in which it is prepared : The stomach of the pig, as soon as possible after re- moval, is laid open and rinsed. The mucous mem- brane is then dissected off from the other coats, stretched out upon a light wooden frame, and dried before the fire, care being taken that it is placed suf- ficiently far off to secure its not being exposed to more than a moderate degree of warmth. In the course of a few hours it becomes thoroughly dried, and may be afterwards hung up and kept in any dry place. When required for use, it is cut into shreds and infused in water. The dried membrane may also be ground to powder, and kept, and used in this form. In my experiments on artificial digestion, I am in the habit of employing twenty drops of strong hydro- chloric acid to the ounce for acidifying the infusion. This makes a very powerful digestive solution. Its efiects are well exemplified by suspending in it the hind lesfs of a froo: for three or four hours at a tem- 76 GASTRIC DIGESTION. perature of about 100°. The immersed portion will be found at the end of the time to be very strongly acted upon, if not completely dissolved. The frog having been killed, the hind parts are detached by division across the spine. The legs are then sus- pended in the liquid by a piece of thread. They form the best medium I know of for displaying the possession or non-possession of digestive power: being easy of digestion and readily showing the slightest action that takes place. Used as a test, if there is no solution of the skin, or softening and separation of the muscles, after four or six hours' exposure to a temperature of about 100°, it may be concluded that the liquid operated on is devoid of digestive power. Temperature influences materially the rate of di- gestion. The higher the temperature short of about 140°, the point at which the virtue of the nitrogen- ized organic principle — pepsin — is destroyed, the more rapid or eijergetic is the gastric juice in its ac- tion. At the ordinary temperature of the atmos- phere, the effect is almost 7iil. A temperature of about 100°, or a little over, is that which in experi- menting it is desirable to employ, thus imitating as near as possible the condition under which digestion is performed during life. Dr. Beaumont found, from numerous observations, that the temperature of Alexis St. Martin's stomach ranged between 98° and 102° when empty, and 99° and 103° when digestion was proceeding. For gastric digestion, then, it may be said that a liquid containing the special organic principle deriv- able from the mucous membrane of the stomach in MODE OF ACTION OF GASTRIC JUICE. 77 combination with an acid, and the existence of a suit- able temperature, form the essential conditions that are needed. If these conditions are supplied, it mat- ters not, as far as the result is concerned, whether the process is carried on inside or outside the living body. Gastric digestion in itself is a purely chemi- cal process. The only part that is dependent on vi- tal action is the production of the organic principle, without which it cannot proceed. It is true, how- ever, that the movements of the stomach afford a mechanical aid, and place natural under more favor- able circumstances than artificial digestion. Different theories have been propounded to ac- count for the modus operandi of the gastric juice. By some it has been suggested that the gastric juice ex- erts its solvent action by what is called catalysis — to give a parallel — that it acts like spongy platinum in the acetification of alcohol. In opposition to this view, it is to be remarked that in changes produced by catalysis the catalytic agent itself undergoes no alteration, and does not become exhausted ; whilst with the gastric juice, observation shows that a given quantity can only dissolve a certain amount of nitro- genized matter. Others have suggested that it acts as a ferment like yeast — that in its organic principle (pepsin) we have a changeable body, which is capa- ble under the presence of an acid of inducing a state of change in the nitrogenized constituents of our food, resulting in solution. Another suggestion is, that the pepsin is in combination with the acid of the gastric juice, so as to form a compound or conjugated acid which possesses solvent properties not enjoyed 78 GASTRIC DIGESTION. by the simple or any other acid. In the case of the human gastric juice, it would be the hydrochloric acid with which the pepsin is combined, the com- pound being styled the hydrochloro-pepsic acid. Bone and metallic substances suffer attack by the gastric juice. For the animal part of bone, the or- ganic principle and acid are required in combination; but the acid alone suffices for the solution of the earthy part. A neat experiment was performed by Sir Astley Cooper, showing the digestibility of bone, and the specimen resulting therefrom is preserved in the Guy's Hospital Museum. One side of a flat slip of bone was varnished over by him with a layer of sealing-wax, upon which he scratched out his name. Upon the other side he wrote his name in sealing- wax, leaving the surface otherwise free. The seal- ing-wax, a non-digestible material, was intended to protect the surface of bone lying underneath it. A dog was then made to swallow the slip of bone with a string attached to it, so that it could be afterwards recovered. After being allowed to remain in the stomach for some hours, it was withdrawn. Upon one side the specimen shows the name engraved, whilst upon the others the letters are seen standing out in relief. Some remarkable specimens that are contained in the Museum of Guy's Hospital, and which were de- rived from the performances of a real knife-eater, who died in the hospital from the effects of his exploits, the early part of the present century, show in a striking manner how strongly metallic substances are attacked by the digestive secretion. The history be- MODE OF ACTION OF GASTRIC JUICE. 79 longing to this man's case is of an interesting nature, and runs shortly as follows : John Cummings, an American sailor, whilst on shore with some of his shipmates in France, saw a mountebank entertaining an audience by pretending to swallow clasp-knives. After returning to the ship, and whilst under the influence of grog, Cummings boasted that he could swallow knives as well as the Frenchman. He swallowed his own knife first; and his shipmates not being satisfied, he afterwards swal- lowed three others. Three out of the four knives were passed by him during the following two days: the other he never saw, nor did he ever experience any inconvenience. Six years later, Avhilst drinking with a party of sailors, he was tempted to boast of his former exploit, adding that he was the same man still. During the course of the evening he swallowed six knives, and on the following day eight more. This time vomiting and severe pain in the stomach ensued, and he was taken to the Charleston Hos- pital, where, according to his own nautical way of expressing it, '^le got safely delivered of his cargo." Nme months afterwards, boasting again of his former exploits, he was driven into repeating his perform- ance. He now paid dearly, however, for his folly, and ultimately became an inmate of Guy's Hospital, where he remained lingering for some time in a dis- tressing state till he died. Whilst in the hospital, he wrote a narrative of his life, w^iich, in his own handwriting, is preserved in the hospital museum. Altogether, the number of knives swallowed by him upon various occasions amounted to at least thirty- 80 GASTRIC DIGESTION. five. Several portions of blades, springs, and handles of knives Avere found in a liighly corroded state in his stomach after death. These, with some speci- mens discharged from him whilst alive, and likewise the stomach, which is in a contracted and corrugated state from the diseased condition that was set up. are deposited amongst the preparations of the museum. The time required for food to be digested in the stomach varies wdth the nature and quantity of the material taken, as well as with the state of the organ as to health. In the observations of Dr. Beaumont upon Alexis St. Martin, a moderate meal of meat, bread, etc., was ordinarily found to undergo digestion, and to disappear from the stomach in from three to three and a half hours' time. As regards rate of di- gestion, however, a good deal depends on the state of subdivision in which the food happens to be on ar- riving in the stomach. In one experiment. Dr. Beau- mont introduced through the fistulous opening into the stomach of his subject two ounces of underdone roast beef, tied to a piece of string to enable it to be withdrawn ; and in four hours' time about half of it only was found to be digested and removed. In dogs, where the food is hastily bolted, and a considerable quantity at a time devoured, I have found undigested remains in the stomach, at the end of twenty-four hours, and even a longer period than this, after they have been fed upon a meal of tripe. With a solid mass, it is only at the surface that digestion can proceed ; whereas with food reduced to a comminuted state, its intimate incorporation with gastric juice is throughout permitted, and so a more thorough INFLUENCING CIRCUMSTANCES. 81 exposure to the digestive influence is brought about. It is not difficult to understand how minuteness of subdivision contributes towards expediting the pro- cess of digestion. " From numerous trials," says Dr. Beaumont, " I am persuaded that moderate exercise conduces con- siderably to healthy and rapid digestion. The dis- covery was the result of accident, and contrary to preconceived opinions. I account for it in the fol- lowing way. Gentle exercise increases the circula- tion of the system, and the temperature of the stom- ach. This increase of temperature is generally about li° Severe and fatiguing exercise, on the contrary, retards digestion. Two reasons present themselves for this : the debility which follows hard labor, of which the stomach partakes \ and the de- pressed temperature of the system consequent upon perspiration and evaporation from the surface." The influence that temperature exerts upon the process of digestion has been already alluded to. In the summary drawn from a large number of observa- tions upon the temperature of Alexis St. Martin's stomach in different states as regards emptiness and repletion, and at different seasons of the year and periods of the day. Dr. Beaumont shows that the temperature is higher during digestion than fasting, and in both these states higher during exercise than repose. For example, with the stomach empty and the body in a state of repose, the temperature ranged between 98° and 1001°, whilst during exercise it ranged between 100° and 102° ; with the stomach full, the range of temperature observed was between 6 82 GASTRIC DIGESTION 99° and 102° during repose, and during exercise be- tween 100J° and 103°. The practice now so common in luxurious life of eating ice-puddings at dinner and ices at dessert is not in harmony, hoAvever agreeable at the time it may be, with physiological principles. From well-ascertained facts, it may be positively asserted that lowering the temperature of the interior of the stomach whilst di- gestion is o'oino: on cannot fail to interfere with and retard the completion of the process. Drinking copi- ously of cold fluids must also exert the same effect as partaking of ice-puddings and ices. Upon one occa- sion, with the thermometer introduced into St. Mar- tin's stomach whilst in an empty state, Dr. Beaumont noticed that the effect of drinking a quarter of a pint of water at a temperature of 55° was to occasion an immediate fall from 99i° to 70°. The temperature stood at this point for a minute and a half to two minutes, and then began very slowly to rise ; but it was not until after half an hour had elapsed that it had risen again to 99°. Alcohol is destructive of the power of the gastric juice by throwing down its pepsin in an insoluble state. It is easily shown by means of experiment outside the body, that the effect of the presence of a certain amount of alcohol is to prevent the process of digestion from being carried out. Now, the same must hold good with regard to digestion in the inte- rior of the stomach; and thus is accounted for the vomiting that constitutes so common a consequence of a debauch, and also the fact that the food which has been taken is found to be rejected in an undi- INFLUENCING CIRCUMSTANCES. 83 gested state. The "petit verre" that is frequently taken after a heavy dinner, or to follow an indigesti- ble article of food, is taken with the view of its afford- ing assistance to digestion; and notwithstanding what has been said, it is not incompatible that it should do so. It is quite consistent that a small quantity of spirit taken into the stomach may expedite digestion by its stimulating effect upon the glandular follicles, leading to an increased flow of secretion ; whilst a larger quantity, by virtue of its chemical action on the secretion produced — by precipitating as it does its active organic principle, should exert exactly the opposite influence on the result. The physical effect produced by gastric digestion upon the food is to transform it into a homogeneous semi-fluid material, which is spoken of as constituting chyme. In color this product of gastric digestion — or chyme, varies according to the nature of the food from which it has been derived. It invariably pre- sents a strongly acid reaction. As it is formed, it gradually passes through the pyloric orifice of the stomach into the duodenum. With this physical change, a chemical action is exerted upon some of the constituents of the food: the nitrogenized group of alimentary principles forming the materials that yield to the chemical influence of the gastric juice. These the gastric juice converts, one and all, into a substance that has received the name of "peptone" from Lehmann, and "albuminose" from Mialhe. In their transformation into peptone or albuminose, the nitrogenized principles lose com- pletely the original distinctive properties they pos- 84 GASTRIC DIGESTION. sessed. The newly formed material, no matter from what source or from what nitrogenized principle it has been derived, presents the same chemical proper- ties. It is soluble in acid, alkaline, and neutral solu- tions, and is not precipitable by heat. Besides the possession of this marked quality of solubility, it is further characterized by being endowed wdth great diflfusibility — a property of the highest physiological importance for it to enjoy, enabling, as it does, to pass by the simple physical principle of osmosis from the aliment ar}^ canal into the circulatory sj-stem. Upon reaching the circulatory system, this peptone or albu- minose doubtless constitutes the pabulum or source from wdiich the nitrogenized proximate principles of the blood are derived. In respect of fibrin and gluten, it may simply be said that they are gradually dissolved by the agency of the gastric juice, the resulting solution containing albuminose. Albumen in a state of solution is not, as is some- times asserted, coagulated like casein. Without any visible change, the albumen undergoes a themical transformation, the solution losing the property of being coagulable hy heat and nitric acid. Coagulated albumen, before being dissolved, becomes pellucid and softened. With a square fragment of hard-boiled white of egg, for instance, submitted to artificial di- gestion, it is observed that the angles and edges first of all lose their opacity. The albumen at the surface becomes converted into a transparent, soft, jelly-like substance, which is afterwards removed by solution. This action being continued, the whole fragment ultimately disappears. I CHEMICAL ACTION EXERTED. 85 Casein is in the first instance precipitated, but afterwards re-dissolved. It is for this reason that milk is invariably curdled in a very short time after being received into the stomach. When re-solution has taken place, the casein is found to have disap- peared, the liquid being no longer precipitable by the addition of an acid. Gelatin in the solid state is dissolved and trans- formed. In solution there is no physical change to be seen, but the property of gelatinizing on cooling is destroyed. Although the special province of the stomach may be said to be the digestion of the nitrogenized group of alimentary principles, yet the non-nitrogenized group do not probably wholly escape undergoing some amount of change in the organ. With the saccharine element, which belongs to this group, no digestion whatever is required to be j)er- formed. Being of a soluble and diffusible nature, the saccharine princple is ready, without requiring to pass through any process of preparation, for absorption. Starch must be acted upon and transformed before it can be absorbed. The stomach is certainly not the organ functionally designed for effecting this transformation. Nevertheless, as suggested by Dr. Bence Jones, the acid of the gastric juice may occa- sion some transformation of starch* into sugar. Fatty matters are emulsified or rendered fit for absorption in the small intestine. According to Dr. Marcet, however, the neutral fats are acidified in the stomach, and thereby placed in a fit condition for being acted upon by the bile, which has the power of 86 GASTRIC DIGESTION. emulsifying the acid, but not the neutral fats. When the fat of meat is eaten, the membranous element belonging to it is dissolved by the gastric juice, and the fat, liquefied by the heat of the body, escapes and diffuses itself in a free state amongst the contents of the stomach. The presence of oily matter intimately mcorpor- ated with or diffused through a substance, renders it difficult of penetration by the gastric juice — and thereby, of digestion in the stomach. Almonds and nuts, and such-like oily articles, owe their well-known indigestibility to this cause. Unless they have been very finely pulverized or comminuted {hy which their indigestible character is removed), before being re- ceived into the stomach, obstruction, as may be readily understood, is offered to their penetration by the watery secretion that is to dissolve them, and so their difficult digestibility is accounted for. Taking the various articles of food that are con- sumed, ordinary experience suffices to teach us that they yield with varying degrees facility to the pro- cess of digestion. Dr. Beaumont, however, conducted an elaborate series of observations upon this matter, and framed a table from which the following extract has been taken. Through the position in which Dr. Beaumont was placed, he was afforded the opportu- nity of noting exactly at w4iat period the digestion of an article was completed ; but it must be borne in mind that his observations were all conducted upon one individual ; and it is possible, if a more extended field of observation had presented itself to him — if he had been enabled to conduct his observations upon DIGESTIBILITY OF FOOD. 87 several individuals instead of only one, some modifi- cations would have occurred in the table that he has produced : at all events, there are points in which the table given certainly does not conform with the notions derivable from general experience. Extract from Dr. BeaumonVs Table, showing the mean time in which various articles of food underwent digestion in the stomach of Alexis St. Martin. Rice, boiled, Milk, boiled, . Do., unboiled. Pig's feet, boiled. Tripe, boiled, . Yenison steak, broiled, Turkey, roasted. Do., boiled. Goose, wild, roasted. Pig, sucking, roasted. Liver, broiled, . Lamb, broiled. Chicken, fricasseed. Eggs, hard-boiled, . Do., soft-boiled, Do., fried. Do., raw. Custard, baked. Cod-fish, cured and dry, boiled Salmon trout, fresh, boiled, Salmon, salted, boiled. Oysters, raw, . Do., roasted. Do., stewed, Beef, fresh and lean, roasted. Beefsteak, broiled, . Beef, hard, salted, boiled. Pork, fat and lean, roasted. Do., recently salted, boiled. Mutton, roasted. Do., boiled. Hrs Mins. 1 00 2 00 2 15 1 00 1 00 1 35 2 30 2 25 2 30 2 30 2 00 2 30 2 45 3 30 3 00 3 30 2 00 2 45 2 00 1 30 4 00 2 55 3 15 3 30 3 00 3 00' 4 15 5 15 4 00 3 15 3 00 88 GASTRIC DIGESTION. Yeal, broiled, . Do., fried. Fowl, boiled, . Do., roasted, . Duck, roasted, . Do., wild, roasted, Beef suet, boiled. Mutton suet, boiled. Cheese, old, strong, Soup from beef, with vegetables Do., barley, Do., mutton, . Do., oyster. Hash (meat and vegetables). Sausage, broiled, Heart, fried, Bread, wheaten and fresh, Sponge-cake, . Apple-dumpling, Apples, sour and hard, . Do. , sour and mellow. Do., sweet and mellow. Parsnips, boiled, Carrots, boiled. Turnips, boiled, Potatoes, boiled. Do., baked. Cabbage, boiled. and bread. Hrs. Mins. 4 00 4 30 4 00 4 00 4 00 4 30 5 30 4 30 3 30 4 00 1 30 3 30 3 30 2 30 3 20 4 00 3 30 2 30 3 00 2 50 2 00 1 30 2 30 3 15 3 50 3 30 2 30 4 30 Seeing that the stomach acts upon and dissolves substances identical with itself, it becomes a question of paramount interest to us, to know how it is that it escapes being itself digested whilst digestion is pro- ceeding in its interior. The position occupied by the stomach amounts in reality to this : a vessel composed say of marble is used as a receptacle in which the process of dissolving fragments of marble is carried on by means of an acid : the fragments are found to dis- ESCAPE OF STOMACH FKOM SELF-DIGESTION. 89 appear, whilst the vessel itself remains intact. The question proposed is one that concerns us at every meal we consume ; for did the stomach yield to the solvent influence of its secretion, like its contents, solution resulting in perforation could not fail to take place^ and must inevitably lead to the destruction of life. John Hunter was the first to direct attention to this point. In a communication published in the " Philosophical Transactions " for 1772, entitled '' On the Digestion of the Stomach after Death," Hunter remarks that in occasional instances, especially in persons who have died of sudden and violent deaths, on making an inspection of the body, the great ex- tremity of the stomach is found so dissolved as to have alloAved of the escape of its contents into the abdominal cavity. He further states, that although a perforation of the stomach may not be observed, yet there are very few dead bodies in which the stomach is not at its greater end in some degree di- gested, this partial digestion being indicated by a thinness and transparency of the membranes, and by the blood which the vessels contain passing out at their digested ends when pressure is made from the larger towards the smaller branches, and appearing like drops on the inner surface. The greatest extent of solution having been ob- served by Hunter, in cases where the individual has been in the enjoyment of perfect health up to the moment of death, he inferred that the phenomenon could not have arisen from disease during life, but 90 GASTRIC DIGESTION. must have been owing to an action exerted by the diirestive fluid after the occurrence of death. The stomach being thus presumed to be susceptible of yielding to the digestive influence of its own secre- tion after death, it became necessary to account for its not yielding in a similar manner during life. Ac- cording to Hunter, it was the "living principle" that aflbrded the required protection to the living organ. "The stomach," he said, "which at one instant — that is, while possessed of the living principle — was capa- ble of resisting the digestive powers which it con- tained, the next moment — namely, when deprived of the living principle — is itself capable of being di- gested, either by the digestive powers of other stom- achs, or by the remains of that power which it had of digesting other things." He further, in illustra- tion, continues: "If it were possible for a man's hand to be introduced into the stomach of a living animal, and kept there for some considerable time, it would be found that the dissolvent powers of the stomach could have no effect upon it; but if the same hand were separated from the body, and introduced into the same stomach, we should then find that the stomach would immediately act upon it." No question can be raised about the fact that the stomach is often found in a more or less digested state after death. Post-mortem examinations supply frequently recurring examples of the gastric solution that Ilimter has described. By artificial means, how- ever, the phenomena may at any time be made mani- fest, and to an extent far more striking than that corresponding with the description that Hunter has ESCAPE OF STOMACH FROM SELF-DIGESTION. 91 given. A rabbit, for instance, being killed whilst the process of digestion is going on, and the warmth of its body being afterwards artificially maintained, an opportunity is given for the occurrence of digestive action after death, and so a truly astonishing result may be occasioned. With a rabbit killed in the evening, and its body exposed during the night to a temperature of about 100° Fahr., I have before now found that, besides the stomach being dissolved away, its contents, escaping into the abdominal cavity, have produced the most extensive ravages upon the sur- rounding parts, the effects reaching as far as the skin upon the side on which the animal has been laid, and to which the gastric juice would gravitate. There can be no question, then, that the secretion of the stomach acts upon and dissolves the organ itself after death, like any other substance subjected to its influence. The reason that more extensive evidence of its action upon the stomach, than a softening of the mucous membrane, is not ordinarily found in post- mortem examinations, is because it often happens that there is no gastric juice in the interior of the organ at the time of death, and because the fall of temperature which the body undergoes after death exercises so great an influence in diminishing the energy of digestive action. Owing to the latter cir- cumstance, the greatest extent of solution is most likely to be encountered during the hot weather of summer, when the fall of temperature after death takes place with the least rapidity. Upon one occasion I procured and experimented upon a stomach filled with contents which had been 92 GASTRIC DIGESTION. removed from a pig that had been killed a few hours after having been fed. Whilst exposed to the ordi- nary temperature of the atmosphere, it remained in- tact, as far as from external appearances could be seen. It was now placed in a situation where it was exposed to a temperature of about 100° ; and in the course of a short time it was found that the contents had acted upon it so as to have caused an extensive perforation, through which they had made their es- cape. Hunter's theory, it has been found, fails to stand when subjected to the test of experiment. An inge- nious experiment, performed by Bernard, of Paris, has shown that the "living principle " does not afford protection, as alleged by Hunter, from the solvent in- fluence of the digesting stomach. Through an arti- ficial opening into the stomach of a dog, Bernard in- troduced the hind legs of a living frog, whilst the process of digestion was being carried on. The legs, he found, were digested and dissolved away, notwith- standing that the frog itself continued alive. I have repeated the experiment, and obtained a confirma- tory result. The above experiment unquestionably proves, in opposition to Hunter's view, that the stomach has the power of dissolving living substances, and, therefore, that the "living principle" does not afford the pro- tective influence that was alleged. As an argument, however, against the "living principle" constituting the source of protection to the stomach from self-di- gestion during life, it appeared to me that it could scarcely be looked upon as conclusive ; for it might ESCAPE OF STOMACH FROM SELF-DIGESTION. 93 be urged that the vitality of the tissues of the frog — a cold-blooded reptilian animal — might suflBce to ena- ble them to resist the digestive influence of its own stomach, and yet be insuflicient to afford the required amount of resistance to the more powerfully acting stomach of a warm-blooded animal like the dog. I therefore performed an experiment in which tissues belonging to a warm-blooded animal were submitted to the digestive action of the dog's stomach. The ear of a rabbit was substituted for the hind legs of a frog, and with what result the following account of the ex- periment will disclose : Whilst a dog in which a gastric fistula had been established w^as at a period of full digestion, the tip of one of the ears of a vigorous rabbit was introduced through the canula into the stomach, and held there with the hands, in order to avoid inflicting any me- chanical injury, or obstructing its circulation by com- pression of its bloodvessels. At the end of two hours the ear was withdrawn, and some spots of erosion — one as large as a sixpenny-piece — were observed on its surface ; but nowhere was it eaten completely through. On being replaced for another two hours and a half, the tip, to the extent of rather more than half an inch, was almost completely removed, a small fragment only being left attached by a narrow shred to the remainder of the ear. The gastric juice seemed to act like a strongly corrosive agent, making first some ulcer-like spots upon the surface, and afterwards extending its action to the central parts. A consid- erable escape of blood took place, especially towards the latter part of the experiment. My own fingers 94 GASTRIC DIGESTION. becoming moistened with the gastric juice that es- caped from the stomach by the side of the ear, felt somewhat sore or tender from the skin having been to a shght extent acted upon. The " living principle " being refuted, it was sug- gested by Bernard that the stomach owes its escape from self-digestion and perforation during life to the power it possesses of renewing its epithelial layer. The stomach, he said, is lined with 'a layer of epithe- lium and mucus, which acts as a kind of varnish in affording protection to the deeper parts. Whilst di- gestion is going on, the epithelium and mucus are constantly being dissolved and removed, like the food contained in the stomach ; but a fresh supply being as constantly reproduced, the organ is maintained in- tact. When death has taken place, the power of re- newing the epithelial lining that has been removed no longer existing, the gastric juice would arrive in contact with the deeper parts, and circumstances being favorable to the continuance of digestive action, would successively exert its soh^ent influence upon them, until the phenomenon of perforation resulted. An exaggerated notion has been formed of the thickness of the layer of epithelium and mucus be- longing to the stomach, through the rapid attack made on the mucous membrane by the digestive fluid after death. When the stomach of a rabbit is re- moved and opened immediately after death, the mu- cous membrane is firm, and lifts off cleanly from the mass of food beneath, without giving any appearance of the existence of an intervening layer of mucus. If a short time only, however, should be allowed to ESCAPE OF STOMACH FROM SELF-DIGESTION. 95 elapse before the stomach is examined after death, a more or less thick, pulpy, white layer will be found adhering to the surface of the mass of food, which looks like a layer of mucus, but consists, in reality, of digested mucous membrane, and constitutes, there- fore, a post-mortem production. Experiment shows that the explanation which re- fers the escape of the stomach from destruction by its own secretion during life to a protective influence exerted by its epithelial layer, will no more stand in- vestigation than the " living principle." I have found (^^ On the Immunity enjoyed by the Stomach from being digested by its own Secretion during Life," "Transactions of the Koyal Society," 1863) that the excision of a patch of mucous membrane from the stomach of a living animal is not followed by diges- tion of the subjacent parts, and thence perforation — phenomena that would be looked for if the protection were owing to the epithelial layer. Digestion goes on in such a stomach without the structure opposite the denuded part exhibiting any evidence of attack. The walls here evince no signs whatever of enjoying less security than elsewhere ; and on the animal being allowed to live, I have found that repair by cicatriza- tion has ultimately completely taken place. Independently of the evidence afforded by experi- ment, it may be assumed, upon reflection, that some- thing more constant — some condition presenting less exposure to the chance of being influenced by exter- nal circumstances — than that resting upon the exist- ence of an epithelial covering, is required to account for the remarkable security from destruction by its 96 GASTRIC DIGESTION. own secretion wliicli the stomach is found to enjoy during life. From the position the stomach occupies as a receptacle for everything that may chance to get swallowed, it can hardly escape having its mucous membrane occasionally abraded; and yet its mtegrity is found to be maintained. Ulceration of the stomach, also, is not of uncommon occurrence ; but it does not necessarily lead to perforation as a result. Perfora- tion, it is true, does sometimes occur as a consequence of ulceration ; but the same event is noticeable in the <3ase of other parts of the alimentary tract, and there is no reason to regard it in the stomach, more than elsewhere, as due to anything besides the ordinary progress of the ulcerative process. Th-e question, it must be considered, then, as to how it happens that the stomach, composed as it is of digestible materials, escapes during life being di- gested itself whilst dis^estion is beins: carried on in its interior, still remains, as far as the explanations al- read}^ referred to are concerned, an open one for solution. It is evident, upon consideration, that whatever explanation claiming any pretensions to sufficiency is given, must comprise some broad prin- ciple of action capable of providing against all con- tingencies — capable of affording, in fact,, that unin- terrupted security during life, which, upon looking around us, we observe the stomach to enjoy. The view that I have offered {" Philos. Trans.," 1863), is founded upon the permeation of the walls of the stomach by an alkaline current of blood ; and this agrees with the principle I have laid down as indispensable, for the circulation of the blood forms ESCAPE OF STOMACH FROM SELF-DIGESTION. 97 with US one of the essential conditions of life. It will not be disputed that the existence of acidity constitutes a necessary condition for the accomplish- ment of gastric digestion. Alkalinity is also a con- stant character of the blood. Now, the walls of the stomach being everywhere permeated by a current of alkaline blood, an opposing influence is raised to the occurrence of digestion. The gastric juice, it may be considered, is constantly tending to penetrate and act upon the stomach, as well as upon the food con- tained in its cavity; but attack upon the stomach is prevented by the destruction of solvent power that is induced by the neutralizing influence exerted by the current of alkaline blood w^hich happens to be always flowing through the gastric walls during life. This view will be found to be perfectly reconcilable with the yielding of the stomach to the digestive in- fluence of its secretion that is noticed to occur after death. As death takes place, the circulation is stop- ped, and the protecting influence is lost that is aflbrded during life. There is only the blood that is stagnant in the vessels to exert a neutralizing effect; and should death happen to take place at a period of di- gestion, the neutralizing capacity of this will be al- together inadequate to prevent the gastric juice that is present attacking the stomach as well as its con- tents. Digestion of both stomach and its contents proceeds as long as the temperature is kept up to a suitable degree for the purpose, and the solvent power of the gastric juice remains unexhausted. In the special arrangement of the vascular distri- bution that is found to exist in the mucous membrane 7 98 GASTRIC DIGESTION. of the stomach, security, according to the view I have propounded, seems to have been rendered, as it were, doubly secure by the doubly effective barrier that may be said to have been provided against the prog- ress of digestion. At the surface of the stomach there exists a closely woven plexus of capacious capillaries, which, as has been previously pointed out, derive their blood, not from arteries, but from the capillaries which course upwards between the gastric tubules. Now, it is from the blood circulating in the capil- laries between the tubules that the acid constituent of the gastric juice is drawn; and it follows, there- fore, that in proportion as acid is separated here, the blood circulating in the capillaries at the surface must be correspondingly increased in alkalinity. Thus, it will be remarked, not only is the alkalinity of the blood greatest just where alkalinity is most wanted for its protecting influence — viz., at the surface — but in proportion as acid flows into the stomach and creates a demand for a protecting influence, so is the blood circulating at the surface rendered more alkaline, and thereby more efficacious as a protecting medium. Looking at nature's arrangement, the act creating a demand for the exercise of neutralizing action en- hances the character of the neutralizing capacity provided. Tliere is another point that is well deserving our consideration. I think it may be put down that the acid and the organic constituent of the gastric juice, the admixture of which is required to produce a solvent menstruum, are not secreted together, and only meet each other at the surface of the stomach. ESCAPE OF STOMACH FROM SELF-DIGESTION. 99 The organic constituent, it is known, is always pres- ent in the mucous layer at the surface, and is prob- ably secreted by the superficial epithelial cells belong- ing to the organ. The fluid part of the gastric juice, on the other hand, containing its acid principle, is only secreted intermittingly ; and from its exuding from the surface, as it does, in little drops, when its flow is excited by the stimulus of food or other ex- traneous matter, it may be considered, without much doubt, as coming from the glandular tubules in the substance of the mucous membrane. Now, if this constitutes the manner in which the gastric juice is formed — if the gastric tubules, which are lined with quite a different kind of epithelial cell to that belong- ing to the surface, secrete only an acid fluid — a sol- vent menstruum is not formed until this fluid reaches the surface, and becomes incorporated with the or- ganic principle that, as already mentioned, is con- stantly present there. Thus, the presence of a liquid endowed with solvent properties, like those possessed by the admixture of acid and pepsin, is avoided in the delicate secreting tubules that extend into the substance of the mucous membrane, and it is left to the current of blood at the surface, which happens to be the most efficient for the purpose on account of its alkalinity being harmoniously increased in corres- pondence with the amount of acid poured out into the stomach, to form the barrier of resistance to the digestive influence. In support of my view, I have found by experi- ment (vide ^'Philos. Trans.") that by stopping the circulation through a portion or the whole of the 100 GASTRIC DIGESTION. stomach, digestive solution, wherever the circulation is arrested, is thereby allowed to proceed as in its ordinary course upon food. As the result of ligatur- ing' the vessels of the stomach in a rabbit, I have witnessed digestion of its walls proceed during hfe to the extent of perforation. On pinching up and placing a ligature also around a portion of the walls of the stomach so as to cause a constricted mass to project into the gastric cavity, this ligatured mass, in which the circulation has been arrested, has been found to yield to digestion, to the exclusion of the other parts of the stomach, as though it consisted of a morsel of food. It will naturally be required of me to reconcile the view I have advocated with the action that has been described, as having occurred on the living frog's legs and rabbit's ear when introduced through a fistulous opening into a dog's stomach, and submitted to its digestive influence. If the circulation, through its neutralizing capacity, affords protection to the stom- ach, why, it may be asked, does it not afford equal protection to the tissues of living animals that may be introduced into its cavity? I thus put the ques- tion plainly, because it is one that requires to be, and is susceptible of being, plainly answered. According to the proposition offered, the stomach is protected because the neutralizing power of its cir- culation is sufficient to overcome the acidity of the gastric juice which is tending to penetrate and attack it. This proposition, it will be seen, involves the result in a question of degree of power between two opposing influences. Suppose the neutralizing power ESCAPE OF STOMACH FROM SELF-DIGESTION. 101 of the circulation to be diminished below a certain point, whilst the strength of the digestive liquid is alloAved to remain the same ; theoretically the result should be in favor of digestion instead of protection, and practically this may be regarded as having been the position in the experiments with the frog's legs and the rabbit's ear. Suppose, on the other hand, the neutralizing capacity of the circulation of the stomach to be allowed to remain in its natural state, whilst the strength of the acidity of the digestive liquid is increased so as to become the superior of the two; theoretically, digestion of the stomach should take place, and practically, as will be presently seen, this is precisely what occurs. With regard to the frog's legs and rabbit's ear ex- periments, the following is the explanation that I have to offer: In the case of the frog's legs, it may be fairly taken that in the amount of blood possessed by the animal we have a neutralizing capacity which is totally inadequate to oppose the strength of acidity belonging to the dog's gastric juice; and so, to fur- nish the required means of resistance to its digestive influence. In the case of the rabbit's ear, its degree of vascularity is so very different — so much less, as compared with that of the dog's stomach, that there is nothing irreconcilable in the one yielding to and the other resisting attack. The widest diversity, for instance, exists in the position of the stomach and that of the ear. The stomach is not only in itself an exceedingly vascular organ, but is completely sur- rounded by equally vascular parts. The ear forms a structure that projects in an isolated manner from 102 GASTRIC DIGESTION. the surface; is only supplied with blood from its base; in texture is of an infinitely less vascular nature than the stomach ; and situated as it was in the ex- periment, it must have been completely surrounded by or bathed in gastric juice. Now, two opposing forces are considered to be in operation, and the result to be dependent upon which is the stronger of the two. Because with its high degree of vascularity the stomach is enabled to exert a sufficient amount of neutralizing influence on the acidity of the gastric juice to stay the progress of di- gestion upon itself, it does not follow that other parts, endowed with a lower degree of vascularity, should be able to do the same. Even with the stomach itself the circulation may be rendered, as will now be shown, incapable of affording the required neutraliz- ing power, by increasing beyond a certain point the strength of acidity of its contents. It has been already mentioned that, on arresting the circulation of the stomach whilst digestion is going on, the stomach yields as well as its contents. This yielding I have observed in the case of the rab- bit to proceed to the extent of perforation ; but in the dog it has only amounted to softening and solu- tion of the mucous or internal coat — a circumstance that evidently depends upon the contents of the stomach being less powerfully acid in the dog than they are in the rabbit ; for, on increasing their acid- ity before the circulation is stopped, digestion more actively proceeds, and soon gives rise to the occur- rence of perforation. It is possible that some acid may be generated from the food in the stomach of ESCAPE OF STOMACH FROM SELF-DIGESTION. 103 the rabbit, as well as derived from the process of secretion ; at all events, the strength of acidity of the contents of the stomach is conspicuously great in this animal. It has just been stated that if an acid be intro- duced into the stomach of the dog, and the circulation through its walls be stopped, digestion afterwards ac- tively proceeds, and soon occasions perforation. A moderate amount of acid suffices for producing this result ; and the dilute phosphoric and the citric are the acids I have employed in my experiments, that no corrosive action should be exerted. In other ex- periments, where the same acids, in the same quan- tities, have been introduced into the stomach, and its circulation allowed to remain free, no digestion of its parietes has occurred. On proceeding further, how- ever, but still without introducing a liquid that would act corrosively on the tissues, the stomach yields to solution, notwithstanding its circulation is left free. In an experiment where dilute hydrochloric acid was employed, perforation took place in an hour and forty minutes, and the stomach throughout was in an ad- vanced state of digestion. A considerable amount of blood, it was found, had escaped from its vessels; and it will be remembered that considerable hemorrhage was also remarked from the rabbit's ear as it was undergoing digestion in the dog's stomach. Thus, in one set of experiments, where a certain quantity of acid is introduced into the stomach, and the circulation of the blood through its walls arrested, it is found to yield to digestion, because there is no neutralizing agency in operation to destroy the acidity 104 GASTRIC DIGESTION. — and thereby the activity — of the gastric juice tend- ing to penetrate and act upon its texture. In another set of experiments, of precisely the same kind, except that the circulation is allowed to remain free, the stomach escapes, because the penetration of its walls by gastric juice in an acid and active state is prevented. In a third kind of experiment the circulation is again left free; but the quantity of acid is increased, and the stomach yields, because, as in the case of the rabbit's ear and frog's legs, the neutralizing capacity of the circulation is insufficient to overcome the acid- ity that is opposed to it. I look upon these results as in the highest degree confirmatory of the view that has been propounded. One point yet remains to be referred to before I dismiss the subject under consideration. It is incom- patible with the view proposed that a living organism should be capable of existing in a free or isolated state in an actively digesting stomach, without yielding to attack, unless it should consist of, or be invested and protected by, an indigestible material. Now, it is well known as a veterinary fact, that larvae of the CEstrus (bots) are sometimes met with in large numbers in the stomach of the horse; and it might appear, at first sight, that we have here an instance standing at variance with the proposition that has been laid down. It will be found, however, if attention be given to the point, that these larvae do not live in an unattached state in the stomach. They exist with their mouths firmly attached to and buried in the inner coat; indeed, the inner surface of the stomach ESCAPE OF STOxAIACH FROM SELF-DIGESTION. 105 is often to be seen hollowed into a number of cells of a honeycomb nature, into which the larvge, from the telescope-like construction of their bodies, can draw themselves so as almost to be concealed. Living upon the juices of the animal they infest, they also become more or less, as it were, a part and parcel of the stomach's parietes ; and it is further to be re- marked that the principle, chitine, which forms the basis of the external tunic of members of the insect tribe, is of an exceedingly indigestible nature. The indi^'estible character of the investment of these larv^ is shown by the fact that, after they become detached, they pass through the stomach and along the alimentary tract, without suffering loss of life, for they are found to be voided in a living state. Professor Simonds has informed me that he has met ^yiih an entozoon (a species of Filaria) which in- habits the last stomach of the sheep. This parasite, however, like the CEstrus, lives firmly attached to the mucous membrane ; and I have not been able to learn that any example can be brought forward of an isolated digestible organism living in the healthily acting stomach without yielding to digestion. The older physiologists discovered, during their early ex- periments on digestion, that leeches and earthworms inserted into perforated metal spheres, and introduced in a living state into the digesting stomach under- w^ent digestion like morsels of ordinary food. I will now proceed to speak of the morbid phe- nomena connected with the action of the stomach. VOMITING. Vomiting constitutes a form of morbid action con- sisting of the rejection of the contents of the stomach by means of violent invokmtaiy muscuhir efforts. The occurrence of the muscuhir efforts without any ejection taking place from the stomach constitutes what is known as retching. Although the act of vomiting cannot be regarded as forming one of the ordinary or natural events of life, yet, when excited by the presence of irritant or noxious matter in the stomach, it must be looked upon as constituting a most salutary process, leading, as it does, to the rejec- tion of ingesta, which, if retained, would prove hurt- ful to the system. It may be compared in its object to the acts of sneezing and coughing — muscular phe- nomena effecting the expulsion of irritating matter from the respiratory passages. The act of vomiting is usually ushered in by a peculiar sense of uneasiness — a feeling of nausea, as it is termed. This is usually accompanied with more or less giddiness or faintness, coldness of the surface, pallor of the lips and face, dejection of countenance, and smallness, feebleness, and irregularity of pulse. As the act is about to be accomplished, the chest is filled with air by a long-drawn and often sonorous in- spiration. The glottis being now closed, the violent VOMITING. 107 muscular efforts that ensue exert a powerful compress- ing action upon the stomach. The cardiac orifice of the organ is at this time relaxed to permit of the es- cape of its contents, which, by the retrograde action of the oesophagus and pharynx that follow, are raised into the mouth, and thence ejected from the economy. The temperature of the surface now rises, and the pulse becomes frequent and full ; but if the vomiting has been severe, a state of general prostration is in- duced. To prevent the vomited matters passing through the nose as well as the mouth, the posterior pillars of the fauces are drawn together so as to shut off the upper from the lower part of the pharynx, precisely as occurs during the process of deglutition. It not unfrequently happens, however, from the suddenness and violence of the expulsive efforts that occur, that some of the vomited matters are driven toAvards and expelled through the nose — a circumstance that adds considerably to the state of discomfort already ex- isting. With prolonged vomiting or retching, a backward flow of bile takes place, probably from an inverted action of the duodenum, into the stomach ; and this accounts for the appearance of bile in the vomited matters that is observed to occur. The color of the bile ejected varies according to circumstances. At the commencement of vomiting it is j^ellow — at a later period it is green. This is seen in cases of sea-sick- ness, as well as in sickness dependent on other causes. As long as any acid remains in the stomach the bile, in passing through, is rendered yellow. As soon, how- 108 VOMITING. ever, as vomiting has been sufficiently prolonged for all trace of acid to be expelled, the bile discharged is green instead of yellow. The compression to which the liver and gall-bladder are subjected will account for the quantit}^ of bile that may be discharged. Much difference of opinion has prevailed regarding the agency by which the contents of the stomach are expelled, or as to the part played by the stomach and abdominal muscles during the act of vomiting. Ma- gendie instituted and performed a series of experi- ments on the subject, and, from the results he ob- tained, maintained that the stomach was perfectly passive during the process, the act of expulsion being wholl}^ effected by the conjoint contraction of the dia^ phragm and abdominal muscles. Observation, it is true, has shown that attempts at vomiting are ineffectual when the stomach is left, as when extruding from the abdominal cavity, to its unaided efforts to expel its contents. This, how- ever, can by no means be taken as proving that its condition is a passive one during the ordinary per- formance of the act. A case has been recorded,^ in which a man was gored by a bull, and left with his stomach projecting from the abdominal cavity. Whilst the stomach was protruding, the efforts at vomiting, and these were very violent, produced no effect ; and no appearance was to be seen of any con- tractile action of the organ itself taking place. Im- mediately, however, that the stomach was returned into the abdominal cavity the same efforts that were 1 Lepine, "Bulletin de 1' Academic dc M^dccine," 1843-4. VOMITING. 109 before ineiFectual in expelling anything from its cavity brought about an ejection of its contents. Such I find, on reference to the original source, to be the facts of this case, which, as far as it goes, tells against the stomach exerting any contractile action . Strangely enough, as the case is quoted by authorities in gen- eral in this country, it is represented as proving ex- actly the reverse of what it really does, it being made to appear that, whilst protruding, the stomach was to be seen forcibly contracting, and that by its un- aided efforts it effected an expulsion of its contents. The phenomena observed in the above case, as men- tioned by Lepine, exactly correspond with the de- scription given by Magendie of the result obtained when an animal was experimentally placed in a simi- lar position. Referring to my own experience, upon one occasion, whilst conducting an experiment upon an animal under the influence of chloroform, the stom- ach was incidentally forced out, during some efforts at vomiting that occurred, through an opening that had been made in the abdominal parietes. The stom- ach at the time was distended with food ; and I noticed that as long as it protruded from the abdominal cavity the efforts at vomiting were ineffectual in causing any expulsion of its contents ; whilst directly it was re- turned, the eflbrts were accompanied with an ejection of food. Evidence of this kind certainly shows that, without the agency of the compressing action exerted by the abdominal parietes, vomiting fails to be eftectively performed ; but it does not show that the stomach is a passive organ in the act. It would be unreason- 110 VOMITING. able to look for the production of any sharp or im- mediate effect by the contraction of the stomach, such as occurs in the case of the abdominal muscles, because its muscular fibres are of a kind that do not act in this manner. They only undergo a slow pro- cess of contraction in respondence to a stimulus ; and in the absence of direct proof to the contrary, it is fair to assume that, like the analogous fibres belong- ing to the rectum and bladder, which unquestionably aid in the performance of defecation and micturition, they help in expelling the contents of the stomach during the act of vomiting. The contraction of the stomach upon its contents would tend to open the cardiac orifice ; and this, it is evident, must form one of the train of phenomena belonging to vomiting, be- cause the mere compression of the stomach by the abdominal parietes, as during violent straining for ex- am]Dle, does not produce an expulsion of its contents. Dr. Marshall Hall contended that the diaphragm takes no share in the production of the expulsive efibrts that accompany vomiting. He considered it to be only muscles of expiration that were thrown into contraction, and compared the act to a forcible expiratory efibrt allied to that of coughing, in which indeed, he remarked the contents of the stomach are frequently expelled. Now, the diaphragm and the other muscles belonging to the walls of the abdomen — the group of abdominal muscles, as they are called — certainly antagonize each other in their effect upon the cavity of the chest, and therefore are not in simul- taneous action in the process of respiration ; but, as regards tlie cavity of the abdomen, the circumstances VOMITING. Ill are clifierent, and harmony is consistent with their simultaneous contraction. In the act of coughing it is necessary that the diaphragm should be relaxed, to enable the abdominal muscles to produce the sud- den expulsion of air from the chest through the open glottis that occurs. In the act of vomiting, how- ever, where the effect required is the compression of the stomach, if the diaphragm formed a relaxed or floating partition between the chest and abdomen, as suggested by Marshall Hall, the action of the ab- dominal muscles would be thrown as much upon the thoracic as upon the abdominal cavity- and with the glottis closed, as is the case, the lungs would be sub- jected to the full force of the muscular contraction taking place. The expulsive effort of vomiting is al- ways preceded by a deep inspiration, and the dia- phragm remaining contracted would both assist in compressing the stomach and in relieving the lungs, the compression of which is not wanted. It is now, indeed, to be stated, as the result of the experimental inquiry of Dr. Anderson,^ that the diaphragm has been actually found to be in a forcible state of con- traction during the act of vomiting. By an anti-peristaltic movement in the oesophagus, the vomited matters are raised from the stomach up into the mouth. This reversed peristaltic action has been witnessed in the oesophagus after the injection of tartar emetic into the veins, even after its separa- tion from the stomach has been effected. It occurs in eructation and rumination, and is here unaccom- 1 "Lond. and Ed. Monthly Journal," 1844. 112 VOMITING. panicd with the retching efforts that are obsei^ved in vomiting. It effects a return of the food and drink in cases of dysphagia; and in simple retching it occurs without being attended with the passage of anything along the tube. We seem to be conscious of its being about to take place, and have the power by swallow- ing of restraining its occurrence for a little while. Some persons have possessed the faculty of eject- ing the contents of their stomach at w^ill, and two cases of the kind — those of Gosse and Montegre — are on record, in which it was turned to account for investigating the phenomena of digestion. Gosse, of Geneva, ejected the contents of his stomach by a true process of vomiting ; and it was by swallowing a quantity of air that he excited the performance of the act. His observations on the digestibility of different articles of food are given in Sennebier's French trans- lation of '' Spallanzani on Digestion." In Montegre's^ case the ejection from the stomach was effected by a process akin to eructation. Without any apparent effort, or any of the muscular phenomena that are seen in vomiting, he could at any time throw up matters from the stomach into the mouth, just as is done by the ruminant animal. Montegre conducted an extensive series of observations upon himself, but was led into error concernimr the nature of the di- gestive fluid. The fluid raised by him at a period of fasting, which presented the characters of mucus and saliva, was mistaken for the pure gastric juice, the strong acidity of the contents of the stomach during 1 Montegre, "Experiences siir la Digestion." Paris, 1814. VOMITING. 113 digestion being attributed, not to secreting action, but to the generation of an acid from the food. According to accounts given us, the act of vomiting used to be sometimes purposely excited by the an- cients to enable them to prolong the enjoyments of the table. The Romans, it is said sometimes excited vomiting to eject from the stomach what they had eaten in one course, that they might be the more capable of enjoying what was to follow. As Seneca has it, ^^they vomited that they might eat, and ate that they might vomit." They emploj^ed emetics be- fore meals that they might be able to eat the more plentifully, and often concluded a feast with an emetic to j^revent the consequences of gluttony. Vomiting is a reflex nervous act, and may be ex- cited not only by causes acting on the stomach, but also by causes acting on a variety of other parts. The most natural cause — if it may be so termed — of vomiting is a source of irritation acting upon the stomach itself. Vomiting thus produced may be due to the introduction of irritant bodies into the stomach ; to the presence of articles of food that prove refrac- tory to or difficult of digestion — these by their pro- longed sojourn becoming a source of irritation to the healthy stomach ; or, lastlj^, to the presence of ordi- nary articles of food in a morbidly irritable or sensi- tive stomach. Vomiting excited by an impression starting from the stomach may further have its source of origin in some morbid condition of the organ with- out the co-operation of any foreign influence. The vomiting that occurs during the passage of biliary and renal calculi, during pregnancy, in perito- 8 114 VOMITING. iiitis, and from hernia or strangulation of the intes- tine, form examples of vomiting provoked by a peripheral irritation not starting from the stomach. The impression derived from mechanical irritation or titillation of the fauces is well known to have the power of exciting vomiting. The first effect that is here produced consists of anti-peristaltic contractions of the pharynx and oesophagus. These are more or less speedilj' followed by a concerted action of the stomach and abdominal muscles, which results in vomiting. As an illustration of the difference in the reflex phenomena that may be produced by the stim- ulation of parts situated in close proximity to each other, it is found that irritation, applied a little be- yond the fauces, excites peristaltic movements, and the performance of swallowing, instead of anti-peri- staltic movements and the performance of vomiting. Instances, for example, are mentioned by Marshall Hall of patients who, in attempting to excite vomit- ing by tickling the fauces with a feather, caused, in- stead, the feather to be swallowed by applying the irritation too far down. The vomiting so frequently observed as a concomitant of a violent paroxysm of coughing is prolj^iblj' in great part, if not wholly, due to reflex action arising from the source of irritation existing at the pulmonary extremities of the pneumo- gastric nerves. The influence of the physical com- pression to which the stomach is subjected by the powerful contractions of the abdominal muscles, that take place during vomiting, may possibly have some- thing to do with it ; but the main cause is probably the irritation of the pneumogastrics referred to. VOMITING. 115 Certain impressions acting upon the special organs of sense — as, for instance, a repulsive sight or a dis- gusting smell or taste — are capable of exciting the performance of vomiting. Even the thoughts of such sensations, and, therefore, an impression starting from the brain, and originating in a mental operation, may suffice, in a susceptible disposition, to afford the re- quisite stimulus for exciting the accomplishment of the phenomenon. The influence upon the sensorium produced by the motion of the body is probably the cause of the vomiting of sea-sickness. The same also applies to the vomiting that in some persons may be induced by swinging; by a rotatory movement of the body, as in waltzing, &c. ; and by the motion derived from riding in a carriage, particularly wdth the back directed toward the horses. In support of its being through an influence upon the sensorium, that the effect is produced under these circumstances, it is w^ell known that the sight of an object in certain kinds of motion may induce a feeling of giddiness and sick- ness. Irritation of the nervous centre, as the result of disease, forms a not unfrequent source of vomiting. It is with morbid conditions of the brain, how^ever, and not of the spinal cord, that vomiting is thus associated. It constitutes, indeed, one of the symp- toms looked for in cases of injury to or disease of the brain, and especially when the base of the organ forms the seat of affection. The spinal cord rarely bears any etiological relation to vomiting. The brain and stomach sympathize in a very in- timate manner with each other. Not only does 116 VOMITING. vomitinjr form so frequent a concomitant, as has been mentioned, of cerebral disease, but the occurrence of headache in association with stomach derangement is also a matter of daily observation. Where a doubt exists as to tlie cause of the vomiting, the following, according to Romberg's experience,^ are the charac- teristic symptoms which indicate that it arises from a cerebral influence : " 1 . The influence of the posi- tion of the head : the vomiting is arrested in the horizontal, and recurs and is frequently repeated in the erect position. It is also easily induced by move- ments of the head, by swinging, shaking, or stooping, or sudden rising. 2. The prevailing absence of pre- monitory nausea. 3. The peculiar character of the act of vomiting : the contents of the stomach are ejected without fatigue or retching, as the milk is rejected by babies at the breast. 4. The complica- tion with other phenomena, the more frequent of which are pain in the head, constipation, and the irregularity of the cardiac and radial pulse, which is increased during and subsequent to the act of vomit- ing. The duration of the vomiting is limited in the inflanmiatory affections of the brain, meningitis, en- cephalitis, and acute hydrocephalus, to the first stages of the disease; and the prevailing rule is, that, as the paralytic and comatose symptoms increase, the vomit- ing remits and ceases." Poisonous agents — as tartarized antimony, arsenic, etc. — induce voniitin«: wdien introduced into the cir- 1 Kombcrg on "Diseases of the Xervous System," Yol. II, p. 19, "Sydenham Soc. Translation." VOMITING. 117 culatorj system, as well as into the stomach. They probably exert a special influence upon the nervous S3' stem that determines vomiting; but the effect may be in part due to a topical action of the agent upon the mucous lining of the stomach; for the stomach is found to exercise an eliminative action upon it. Thus, in some experiments, where I had injected the poison into the veins of dogs, it was afterwards chemi- cally recognized amongst the contents of the stomach and intestine by Dr. Alfred Taylor; and some mice were killed by eating the vomited matter from a dog so experimented upon. The vomiting which may at- tend the invasion of an acute febrile, exanthematous^ or pestilential malady, is probably dependent upon the action of a morbid or poisoned condition of the blood upon the nervous system. In the treatment of vomiting, the practitioner has to be guided by the nature of the cause in operation, and a knowledge of this can only be arrived at by a careful inquiry into the history and circumstances belonging to each case. The object to be attained is to allay the irritability of the stomach, and remove the source of irritation, wherever it may be, that con- stitutes the primary cause of the complaint. For allaying irritability of the stomach, the hydro- cyanic acid is one of the most useful remedies. It may be given in an effervescing draught of bicarbo- nate of potash and citric acid, or fresh lemon-juice, which is better, and a drachm of the tincture of co- lumba ; or in a mixture with conium or hyoscyamus, and the carbonate of magnesia; or else in lime-water. Creasote has been highly extolled as a remedy for 118 yo:\riTiNG. vomiting, but general experience is to the effect that its value has been much overrated. In inflammatory conditions of the stomach, it is calculated to aggravate rather than relieve the condition of the patient. Opium or morphia will sometimes succeed in afford- inf>- relief where all other measures have failed. A striking instance of this kind occurred not long ago amongst my in-patients at Guy's Hospital. A mid- dle-aged man had been suffering from incessant vom- iting for many weeks, and had become reduced to an extreme state of emaciation. His case was such as to lead to the opinion that malignant disease of the stomach existed, and a fatal result seemed rapidly approaching through the effects of sheer inanition. After a number of remedies had been prescribed in vain, half a grain of morphia was ordered to be taken, in the form of a pill, three times a day. The pill was retained, and its effect was almost miraculous. The vomiting ceased ; and the patient, upon whose case such a grave opinion had been formed, and who seemed at the very verge of death, was restored so as to be able to leave the hospital in about three weeks' time. When opium and morphia are rejected from the stomach, an opiate cljster or suppository may be employed. Benefit is in some cases derived from remedies such as chloroform and chlorodyne. The hyposulphite of lime has been recommended in vomitino:, associated with the presence of sarcinw in the vomited matters. It certainly has a destructive influence on the life of these and other such like low members of organiza- tion, but the development of sarcince is almost in- VOMITING. 119 variably accompanied with the existence of organic disease. Attention must not be omitted to be given to the state of the bowels. These should be kept open by the administration, if necessary, of some mild form of laxative (all irritant purgatives must be avoided) ; or by the use — and this is often better — of emollient or purgative enemata. A mustard poultice applied to the pit of the stom- ach is frequently attended with the best result. Where a more permanent counter-irritant action is required, a blister should be employed instead ; and savin oint- ment may be used to keep the blister open. In some cases it may be desirable to establish a blister, and apply morphia to the blistered surface, instead of ad- ministering it by the mouth. Ice is a most useful adjuvant in the treatment of vomiting. It often succeeds in allaying irritability of the stomach, and relieving the distress of the pa- tient more than an^^thing else. It should be broken into pieces, and placed by the bedside, so that it may be taken whenever the patient pleases. In all cases it is of the first importance to pay strict attention to the regulation of the diet. It is no use putting food into the stomach that is sure to be im- mediately rejected by vomiting. Harm can only re- sult therefrom. As long as the stomach is totally intolerant of food it should be withheld, and, if necessary, nutrient enemata administered. By rest an opportunity is given for the restoration of the organ to a more natural state, or a less irritable con- dition. If any food can be retained, the quantity 120 VOMITING. taken — whether a tablespoonful, dessertspoonful, or teaspoonful — should be within the limit of what can be kept down. The quantity of food, in other w^ords, should be reduced to that amount, wdiatever it may be, which the stomach is found capable of retaining, compensation being made for the reduction called for by increased frequency of administration. The food given should be of the most nourishing, easily diges- tible, and least irritating kind that can be found; and nothing comes up to what is required better than milk — an article of food provided for us by nature during our most tender age, and when the digestive organs are first called upon for their exercise of func- tional activity. Lime-w^ater is often a useful addition to the milk, to enable it to be more easily retained. Bread, or some other farinaceous substance, should form the first other kind of food to be allow^ed. Its instructive and telling nature, and the high es- timation in which I hold the plan recommended, must form my apology for transcribing here the celebrated and often quoted account given by Dr. William Hun- ter of " The successful Cure of a severe Disorder of the Stomach by Milk taken in small quantities at once," in a communication contained in the sixth volume of the " Medical Observations and Inquiries." " Many years ago," says Dr. Hunter, '' a gentleman came to me from the eastern part of the city, wdth his son, about eight or nine years old, to ask my ad- vice for him. The complaint was great pain in the stomach, frequent and violent vomitings, great w^eak- ness, and w^asting of flesh. I think I hardly ever saw a human creature more emaciated, or wdth a look VOMITING. 121 more expressive of being near the end of all the mis- eries of life. The disorder was of some months' stand- ing, and, from the beginning to that time, had been growing more desperate. He was at school when first taken ill, and concealed his disorder for some time ; but growing much worse, he was obliged to complain, and was brought home to be more carefully attended. From his sickly look, his total loss of appetite, besides what he said of the pain which he suffered, but espe- cially from his vomiting up almost everything which he swallowed, it was evident that his disorder was very serious. " Three of the most eminent physicians of that time attended him in succession, and tried a variety of medicines without the least good effect. They had all, as the father told me, after sufficient trial, given the patient up, having nothing farther to propose. The last prescription was a pill of solid opium ; for in the fluid state, though at first the opiate had stayed some time upon his stomach, and brought a tem- porary relief, it failed at length, and like food, drink, and every medicine which had been taken, was pres- ently brought up again by vomiting. The opiate pill was therefore given in hopes that it would elude the explusive efforts of the stomach. It did so for a time; but after a little use, that likewise brought on vomiting. Then it was that his physician was con- sulted for the last time, who said that he had noth- ing further to propose. " Though at first the boy professed that he could assign no cause for his complaint, being strictly in- terrogated by his fiither if he had ever swallowed any- 122 VOMITING. thing that could hurt his stomach, or received any injury hy a hk^w or otherwise, he confessed that the usher in the school had grasped him by the waistcoat at the pit of his stomach, in a peevish fit, and shaken him rudely, for not having come up to the usher's expectation in a school exercise — that, though it was not very painful at the time, the disorder came on soon after. This account disposed the father to sus- pect, that the rude grasp and shake had hurt the stomach. With that idea he brought him to me as an anatomist, that an accurate examination might, if possible, discover the cause or nature of the disorder. " He was stripped before the fire, and examined with attention in various situations and postures; but no fulness, hardness, or tumor whatever could be discovered ; on the contrary, he appeared everywhere like a skeleton covered with a mere skin ; and the abdomen was as flat, or rather as much drawn in- wards, as if it had not contained half the usual quan- tity of bowels. "Having received all the information that I could expect, and reflected some little time upon the case, I wished to speak with the father alone in another room ; and, to give my patient some employment as well as refreshment, asked him to take a little milk in the meantime. But his father begged that taking anything into his stomach might be put off till he got home, because he was certain it would make him sick. Just before we set out, said he, I gave him a little milk ; but he was sick and brought it all up in the coach before we had got many paces from the house. VOMITING. 123 "In the adjacent room I said to the father: This case, sir, appears to me so desperate, that I could not tell you my thoughts before your son. I think it most probable, no doubt, that he will sink under it ; and believe that no human sagacity or experience could pretend to ascertain the cause of his complaint; and without supposing a particular or specific cause, there is hardly anything to be aimed at in the way of a cure: yet, dreadful as this language must be to your ear, I think you are not to be without hope. As we do not know the cause, it may happen to be of a temporary nature, and may of itself take a favor- able turn; we see such wonderful changes every day in cases that appear the most desperate, and especi- ally in young people. In them the resources of na- ture are astonishing. " Then he asked me if I could communicate anv «/ rules or directions for giving him a better chance of getting that cure from nature which he saw he must despair of from art. " I told him that there were two things which I would recommend. The first was not so important, indeed, yet I thought it might be useful, and certainly could do no harm. It was to have his son well rubbed, for half an hour together, with warm oil and a warm hand, before a fire, over and all around his stomach, every morning and evening. The oil, per- haps, would do little more than make the friction harmless as well as easy; and the friction would both soothe pain, and be a healthful exercise to a weak body. "The second thing that I was to propose I im- 124 YOMITIXG. agiiied to he of the utmost consequence. It was some- thing which I had particularly attended to in the disorders of the stomach, especially vomitings. It was carefully to avoid offending a very weak stomach, either with the quantity or quality of what is taken down ; and yet to get enough retained for supporting life. I need not tell }'ou, sir, said I, that your son cannot live long without taking some nourishment; he must be supported to allow of any chance in his flivor. You think that for some time he has kept nothing of what he swallowed; but a small part must have remained, else he could not have lived till now. Do not you think, then, that it would have been bet- ter for him if he had only taken the very small quan- tities which remained with him, and were converted to nourishment? It would have answered the end of supporting life as well, and perhaps have saved him such constant distress of being sick and of vom- iting. The nourishment which he takes should not only be in very small quantity at a time, but in quality the most inoffensive to a weak stomach that can be found. Milk is that kind of nourishment. It is what Providence has contrived for supporting ani- mals in the most tender stage of life. Take your son home, and as soon as he has rested a little, give him one spoonful of milk. If he keeps it some time with- out sickness or vomiting, repeat the meal; and so on. If he vomits it, after a little rest try him with a smaller quantity, viz., with a dessert or even a tea- spoonful. If he can but bear the smallest quantity, you will be sure of being able to give him nourishment. Let it be the sole business of one person to feed him. VOMITING. 125 If you succeed in the beginning, persevere with great caution, and proceed very gradually to a greater quan- tity, and to other fluid food, especially to what his own fancy may invite him ; such as smooth gruel or panada, milk boiled with a little flour of wheat or rice, thin chocolate and milk, any broth without fat, or with a little jelly of rice or barley in it, etc., etc. " We then went in to our patient again ; and that he might be encouraged with hope, and act his part with resolution, I repeated the directions with an air of being confident of success. The plan was simple, and perfectly understood. They left me. " I heard nothing of the case till, I believe, be- tween two and three months afterwards. His father came to me with a most joyful countenance, and with kind expressions of gratitude told me, that the plan had been j)ursued with scrupulous exactness, and with astonishing success — that his son had never vomited since I had seen him — that he was daily gaining flesh and strength, and color and spirits — and now grown very importunate to have more sub- stantial food. I recommended the change to be made by degrees. He recovered completely ; and many years ago he was a healthy and very strong young man." Following this account is an appendix under the form of a letter from Mr. William Hey, of Leeds, to Dr. Hunter, containing reports of four cases in which Dr. Hunter's plan of treatment had been put into practice with the same success as in the case above. My own experience is in the highest degree confir- matory of the value of the plan. Several cases have 126 VOMITING. come before me in my hospital practice, where, through its ageiic}^, all that could be desired has been attained, whilst the patients had been under medical treatment for some time previous to admission, and nothino' had oiven them relief. ERUCTATION.— RUMINATION. Gaseous, liquid, and solid matters are sometimes expelled from the stomach and raised mto the mouth without any visible muscular effort, such as occurs in vomiting. This eructation or belching is a common symptom of indigestion. Something suddenly rises from the stomach into the mouth without any previ- ous feeling of nausea. The phenomenon results from a contraction of the muscular fibres of the stomach, a relaxation of the cardia, and a reversed peristaltic action of the oesophagus, without the co-operation of the abdominal muscles, as in vomiting. An irregular muscular contraction produced by a morbid stimulus, usually the result of defective or impaired digestion, may be looked upon as forming the rationale of its occurrence. The eructation of gas is a very common circum- stance, and may depend upon the nature of the in- gesta without the existence of any deviation from health. In cases of flatulence the eructation of large quantities of gas may take place, forming a source of considerable inconvenience and sometimes annoyance, although affording relief to the feeling of distension that exists. Sometimes the gas discharged is of a fetid character 128 ERUCTATION. — may be so foul, indeed, as to render the person's presence almost unbearable to others. Owmg to im- perfect secreting action, or a defective state of the gastric juice, putrefactive changes are allowed to take place amongst the .con tents of the stomach, and as the result sulphuretted hydrogen and such-like gas- eous products of decomposition are evolved. Hence, the belchings presenting the smell of rotten eggs. An emetic hy emptying the stomach at once relieves the condition for the time. The fluids eructated vary much in character and quantity. Sometimes the patient is troubled with the rising of a small quantity of liquid into the mouth during digestion which may be more or less tasteless, saltish, acid, bitter, or acrid. In acidity of the stom- ach, the fluid brought up may be so sour as quite to set the teeth on edge. In cardialgia or heartburn, the eructation is attended with the rising of a small quantity of fluid to the back of the mouth, of so acrid a character as to produce a most unpleasant burning sensation in the parts over which it has passed. In pyrosis or waterbrash, large quantities of an almost tasteless or slightly saltish fluid are brought up with- out any effort or distress. The patient is often aston- ished at the amount of "clear water" that is thus brought off" from the stomach. Infants at the breast sometimes suddenly reject the milk that has been swallowed. Without any warning and without any appearance of effort, the milk suddenly gushes from the inflmt's mouth. This phenomenon has been called regurgitation, but I cannot see that it essen- tially differs from what is known as eructation. ERUCTATION. 129 The eructated material may consist of undigested or of imperfectly digested food. The rising of a little food into the mouth is not a matter of uncommon occurrence. In some of the cases that especially occur amongst hysterical females, and that are described as cases of vomiting, the food that is taken is returned by a process rather akin to that of eructation than that of vomiting : the matters being thrown off with- out any appearance of effort, and without any feeling of nausea or distress. It was by eructation that Mon- tegre discharged the contents of his stomach at will. Even when fasting, as in the morning on rising, he could eject in this way a clear watery fluid from his stomach. The treatment of eructation must be regulated by the nature of the rejected matter. In the eructation of ordinary flatus, when it amounts to an inconve- nience, the remedies recommended for ^^ flatulence" must be employed. Flatulent eructations of a marked kind are common in hysteria and hypochondriasis ; and in such cases, besides carminatives, agents for combating these affections are called for. Fetid eruc- tations will in general be found to be counteracted by pills containing a quarter or half a minim of creasote given with each meal. Simplicity of diet should also be conjoined — hashes, stews, and rich made dishes being especially productive of a foul stomach. Should the rejected matter be of a fluid nature, the treatment for acidity, heartburn, or pyrosis, will have to be put in practice, according to the circumstances of the case. If solid matter is raised, careful mastication 9 130 RUMINATION. and moderation in eating must be enjoined, and an improvement of the digestive power eifected. Some few instances are on record of persons who have been in the reguhir habit of returning the food that has been swallowed, and subjecting it to a second mastication, as is done by the ruminant animal. Dr. Copland^ has placed together a humorous collection of recorded cases of human rumination ; and has fur- ther described some instances (amongst which one seems to have been of a well-marked character) that have fallen under his own observation. Fabricius, who furnished two of the earliest instances of human rumination recorded, believed, we are told, the subjects of it to be endowed with a double stom- ach, and that other bestial attributes might in process of time appear in them or their descendants. His first case is that of a nobleman, who always returned his meals, in general about an hour after they had been taken, to undergo a second and more deliberate mastication. The father of this person is stated to have had a horn growing from his forehead ; and the remark is gravely made, that although the son did not inherit his father's horn, yet he possessed the ac- companying faculty of rumination. His second case is that of a monk, who, it is said, combined the bes- tial attributes of both the father and son above re- ferred to, having had, in addition to enjoying the faculty of rumination, his forehead adorned with a couple of horns. ^ "Dictionary of Practical Medicine," Art. " Eumination. " EUMINATION. 131 Sennert has left behind him an account of a man of forty, who possessed the ruminating faculty from a child. Learning that this person had lost his mother when an infant, and had been fed with milk warm from a cow, he found no difficulty in account- ing for the affection, his conclusion being that he sucked it in with his nurse's milk ! Recchi, it is said, seated over his cups with his friends, at the conclusion of dinner, was always obliged to retire, about half an hour after the meal, into a remote corner of the apartment, to ruminate tlie food he had taken. Being asked how he became obliged to indulge in this propensity, he answered that from a boy he had been subject to acid eructa- tions ; and that after having reached his thirtieth year he found it impossible to resist admitting into his mouth the food that constantly gurgitated from his stomach. Being further interrogated, whether the second mastication of his food afforded him any gratification, "Indeed," he replied, "it is sweeter than honey, and accompanied with a more delightful relish."^ Dr. Copland states that the first case which came under his own observation was treated in 1819 and 1820, and that since the publication of it in the forty- fifth volume of the "London Medical and Physical Journal," two others — one of them in a medical man — have been treated by him ; and that he has reason to believe that instances of partial or occasional rumi- nation are not so rare in the human subject as is 1 Dr. Copland, op. cit. 132 RUMINATION. generally supposed. The report given by Dr. Cop- land of the fully developed case, which continued for some time under his care, runs as follows : " The patient was a married man of about twenty- seven or twenty-eight years of age. Kumination took place after all his principal meals. His appe- tite was always good, and his food was taken in large mouthfuls, was masticated hastily and imperfectly, and swallowed eagerly, chiefly in order to resume his avocations. There was no thirst. His bowels were habitually costive. His sleep was sound. " Usually rumination commenced from a quarter of an hour to an hour after a meal. At its com- mencement a sense of fulness was felt at the cardia, followed by a fuller respiration than usual. As soon as inspiration was completed, a bolus of the unchanged food rose rapidly from the stomach, during the ex- piratory act or preceding this act; and so rapidly did expiration succeed to regurgitation of the alimentary bolus, that the latter appeared as part of the expira- tory act. The rumination process was never accom- panied, at any time, with any degree of nausea, nor with pain or disagreeable sensation. The returned alimentary bolus was attended by no unpleasant flavor, was in no degree acidulous, was equally agree- able, and was masticated with greater pleasure, and much more deliberately, than when first taken. " The whole of the food taken at any one meal was not thus returned for mastication — only the part which had undergone this process insufficiently, and which often constituted the greater part of the ali- ment. That taken at the commencement of a meal RUMINATION. 133 was generally first disgorged ; but tliis order was sometimes not observed, mucli depending upon the articles partaken of, and their comparative degrees of comminution and digestibility. The more fluid portions of a meal w^ere not always returned, unless along with the more solid or imperfectly masticated parts ; and it was often then observed, if a consider- able time had elapsed from their deglutition, that the former was more or less acid, whilst the latter possessed the same taste and flavor as when first swallowed. When the stomach was distended sud- denly by a large meal, the fluid as well as the more solid contents were generally regurgitated, and again swallow^ed after more or less mastication." The possession of a double stomach was associated by some of the older authorities with the occurrence of the phenomenon of rumination. Actual dissection, however, as might be expected, has been found to lend no support to such a proposition, and nothing structurally has been discovered to account for the affection. Peter Frank Avas of opinion, that in per- sons who suffer from eructations and are voracious, rumination is induced by a bad habit, the not un- pleasant taste of ruminated matter offering an en- couragement to the repetition of the process. The affection is generally accompanied with derangement of the digestive organs, flatulence, and especially a quick or voracious mode of eating. This latter seems to form the chief exciting cause, the predisposing cause being a morbid irritability of the stomach. The affection in its fully developed condition seems to be partially, and partially only, under the control 134 RUMINATION. of the will. In Dr. Copland's case, above cited, when the ruminating process was prevented, as it was, by the supervention of sound sleep after a meal, or vol- untarily suppressed, the injesta w^ere not returned for some hours, were then acid, or often acrid and bitter, and were occasionally regurgitated in so large a quan- tity as to fill, or even more than fill, the mouth. As regards treatment, more, we are told, may be expected from careful mastication and attention to slowness and moderation in eating than from any- thing else. Attention should also be paid to the state of the secretions and the bowels. PERVERTED APPETITE. ' By the sense of appetite we are made conscious that food is required, and are prompted to take it. The sense also guides us as to the amount proper to be taken, if not counteracted by variety, which is gratifying to the palate, and so creates a desire that must not be mistaken for appetite. In its more ad- vanced stage, the feeling which tells us food is wanted constitutes hunger. Perverted conditions of the ajj- petite occur, and are of three kinds : 1, excessive appetite ; 2, loss of appetite ; and, 3, vitiated ap- petite. An inordinate appetite, or hidimia^ may be habitual, and proceed from a gluttonous disposition. It fre- quently arises from worms in the alimentary canal ; or it may be caused by grave disease existing either in the digestive organs, or some other part of the system. Inordinate appetite is often observed in organic affections of the stomach, pylorus, and mes- enteric glands. It forms one of the symptoms of dia- betes mellitus, and is sometimes observed in chronic disease of the brain — that form of it which leads to insanity accompanied with general paralysis. Anorexia, or loss of appetite, occurs as a symptom of dyspepsia, and with various other morbid condi- tions of the system. The state may be such that the 136 PERVERTED APPETITE. very sight of food or the thought of eating may suffice to excite a feeling of loathing or disgust. The falling off of the appetite that is found to be experienced under exposure to heat, as during the hot weather of summer, or from residence in a tropical climate, must not be mistaken for an unnatural oc- currence. It is in wise harmony with the require- ments of the case, there being a much less demand for food during hot than cold weather. Vitiated appetite, or ^j^'ca, constitutes that state in which there is a depraved fancy or craving for un- natural substances as food. It is sometimes noticed in children, and frequently in idiots. It likewise forms an occasional phenomenon belonging to preg- nancy, hysteria, and chlorosis. Fancies for all sorts of things have in their turn existed, and the objects of desire have sometimes been of the most incredible and disgusting description. The treatment of these perversions of the appetite will depend upon the nature of the cause producing them. General principles must point to the appro- priate course to be adopted. PAIN AND OTHER MORBID SENSATIONS CONNECTED WITH THE STOMACH. Beyond experiencing a feeling of appetite, or in its more exalted form, of hunger, when the system is in want of food, and a sense of satiety when enough food has been taken, we ought to experience no sensation referable to the stomach. Under natural circum- stances, the process of digestion is performed without giving rise to any consciousness of its progress. When derangement, however, exists, the person becomes conscious, and often most painfully so, that he has such an organ as a stomach, and such a function to perform as that of digestion. Pain, or if not pain, un- easiness, under some shape or other, is one of the most frequent concomitants of deranged digestion; and sometimes it exists without any other manifesta- tion of perverted action. The morbid sensations referable to the stomach are exceedingly numerous and varied in their character. By far the most common form of morbid phenomenon connected with sensibility is a sense of fulness or tightness — a feeling of distension or of weight or heaviness at the pit of the stomach. The least quan- tity of food may excite this sensation in the dyspeptic — an unnaturally voluminous meal will occasion it in the healthy subject. 138 PAIX AND OTHER MORBID SENSATIONS. The opposite sensation is a feeling of emptiness or sinking — a sense of vacuity at the pit of the stomach. This occurs as the natural consequence of want of food ; but it may also be experienced when the supply is plentiful. Patients aifected with tapeworm com- plain of frequently experiencing this sense of empti- ness; and in some cases of diabetes mellitus I have known it urgently complained of, even whilst food is being constantly administered, and when no evidence has existed, judging from the state of the body, of there beinor anv defect of nutrition. A sense of con- stant emptiness at the pit of the stomach, it is true, is one of the ordinary symptoms of diabetes, where the disease is allowed to run on in a severe form, and emaciation of the body is advancing; but I have upon a few occasions also met with it in quite a different form of the complaint: in stout and elderly persons, for example, who have been passing scarcely beyond or not beyond the natural quantity of urine, and this not much charged with sugar. In the cases I am alluding to the distress has been such, from the sense of emptiness experienced, as to cause the patients frequently to exclaim to their friends that they felt sure they were sinking. Nausea, or feeling of sickness, is that distressing sensation which generally precedes vomiting. It may be experienced, however, without being followed by such a result. It forms a frequent accompaniment of dyspepsia. Another morbid feeling, not unfrequently encoun- tered, is a burning sensation or a sense of heat at the pit of tlie stomach. It forms one of the phenomena PAIN AND OTHER MORBID SENSATIONS. 139 of heartburn, and may be also experienced in pyrosis or water-brash. The morbid sensation encountered may constitute what is understood as falling under the denomination of actual pain, and pain of various kinds may occur. The pain, for instance, is sometimes described as of a dull, aching character ; sometimes a burning pain ; sometimes a gnawing pain ; and sometimes a sharp, colicky, or griping pain. Various other expressions are also used to denote the kind of pain experienced. The occurrence of severe pain of any kind is as a rule popularly spoken of as spasm or cramp of the stomach. It may be to spasm that it is due, as in the pain produced by flatus ; sometimes the pain produced by indigestible articles of food, or irritating matter in the stomach ; and in that occurring as an accom- paniment of lead colic. But pain likewise owes its origin to inflammatory and organic affections of the stomach ; and may further arise, without any asso- ciated structural disease, from the condition of the nerves of the organ, so constituting what may be looked upon as a kind of neuralgia. This last form of pain will presently receive attention under the name of gastrodynia. An attack of severe pain occurring in a gouty sub- ject is frequently put down as gout in the stomach. It does not seem clear, however, that such an affec- tion as "gout in the stomach," strictly speaking, has been made out to exist. Dr. Brinton, in his work on the stomach,^ devotes a chapter to answering the 1 "Lectures on Diseases of the Stomach," 18G4. 140 PAIN AND OTHER MORBID SENSATIONS. que^ition, which years ago, he says, he often used to ask himself, and since then has had so often pressed upon him by others — What is gout in the stomach ? After examining the various claimants to this title he remarks, "Is there any gout in the stomach left after the subtraction of these various affections ? I can only say that I know of no such case — have never seen any one — have never been able to get trust- worthy evidence of one from some of the most ac- com23lished physicians living, or from the best rec- ords." Sir Thomas Watson says: "You will meet sometimes with what is called spasm of the stomach (and I suppose it is such) in gouty people, who are then said to have gout in the stomach. The pain comes on in sudden and severe paroxysms, and is re- movable in general by laudanum and stimulants — brandy, for example — or by the mustard poultice. On these cases, however, we look with jealousy and apprehension. In some instances the attack is really inflammatory, and would then be aggravated by a stimulant treatment." Further on he suggests that it will always be well when a reputed attack of gout in the stomach occurs to inquire wdiether any indiges- tible food has been lately taken; '^ for gout (so called) in the stomach has sometimes turned out, under the test of an emetic, to have been nothing more than 2:)ork in the stomach." The form of pain that is comprehended under the terms gastrodynia {yaffrr^p^ stomach: odu',rj^ pain), and gastralgia {raffzr^p, stomach; rUyiw^ I suffer pain), often bears the aspect of an individual or independent affec- tion. It may be regarded as of the character of neu- PAIN AND OTHER MORBID SENSATIONS. 141 ralgia, and exists, not only unassociated with any evidence of structural disease, but sometimes also as the only manifestation of gastric derangement. It is a very common affection amongst the poor, and is a great deal more frequently met with in the female than in the male sex. The nervous temperament and the hysterical, hypochondriacal, and gouty dis- positions predispose to the affection. A close sym- pathy exists between the stomach and the uterus, and gastrodynia is a frequent attendant on uterine derangement. The pain of gastrodynia is oftentimes exceedingly severe. The situation to which it is referred is the pit of the stomach; and, if the question be put, it will be found that complaint is made of its extending through the body to the back between the shoulder- blades. As the loins form the part of the back to which pain from affections of the kidney is referred, so the part between the shoulder-blades forms the region for pain associated with stomach affections. Much variety exists respecting the period of occur- rence, and the duration of the pain in different cases. In general it is at a variable period after taking food that it comes on, and it may afterwards last for some hours. Sometimes it is upon an empty stomach that the pain is experienced, and taking food affords relief. The pain may come on suddenly, and as sud- denly disappear ; the patient during the interval en- joying perfect ease. Gastrodynia is not an affection that endangers life ; but it is often a most wearisome one to bear, and a difficult one to cure. It may be difficult at first to 142 PAIN AND OTHER MORBID SENSATIONS. distinguish the pain of gastrodynia from that of chronic inflammation, ulceration, and malignant dis- ease ; but in a more advanced stage of the case the diagnosis, as a rule, is easy enough. In gastrodynia the pain is not aggravated, but even generally, on the contrary, eased by pressure. It is unattended with tenderness or fever, and does not lead to the produc- tion of that emaciation and cachexia which form ac- companiments of structural disease. In the treatment of gastrodynia a careful investi- gation of the patient's case must be made, and atten- tion, in the first place, directed to rectifying any functional error that may be found anywhere to exist. When gastrodjaiia is accompanied, as it often is, with a coated tongue and other evidence of gastric derangement, the hydrocyanic acid with carbonate of magnesia and conium, in peppermint- water or some such carminative vehicle, may be administered ; or hydrocyanic acid with carbonate of soda or potash, rhubarb, and calumba. Bismuth and the nitrate of silver exert a special curative influence in cases of gastrodynia. They often afford relief to the pain when every other agent has failed. A granular effervescing citrate of bis- muth is made, and forms an elegant preparation. An old and effective formula from the Guy's pharma- copoeia is a combination of nitrate of bismuth Avith carbonate of soda and powdered conium leaves. In the new edition, hydrochlorate of morphia is substi- tuted for the conium. The nitrate of silver was introduced by Dr. James Johnson, who had been himself a martyr to stomach PAIN AND OTHER MORBID SENSATIONS. 143 complaints. It may be given in the form of a pill, beginning with a quarter of a grain or half-grain dose, three times a day. Its employment cannot be con- tinued for more than two or three months without a risk of producing a darkening effect upon the skin. Dr. Abercrombie extolled the sulphate of iron with aloes and aromatic confection in cases of gastrodynia, his statement being that he had found nothing of more general utility than the sulphate of iron in doses of two grains, combined with one grain of aloes and five grains of aromatic powder, taken three times a day. As in the treatment of the other forms of gastric derangement, careful attention must be paid to diet and the various other hygienic requirements. FLATULENCE. Flatus or gas is apt to accumulate in the stomach, and give rise to a condition which forms one of the most common phenomena of deranged digestion. Three sources exist for gaseous matter encountered in the stomach : First, it may be derived from air reaching the stom- ach by being swallowed. Secondly, it may form a product of secretion or elimination from the blood by the mucous membrane. The presence of gas in the swimming-bladder of the fish sufficiently shows that gas may be eliminated in this way. Thirdly, it may be generated as a product of fer- mentation or decomposition from the ingesta or other contents of the stomach. With a weakened state of the digestive powers, ordinary fermentation and de- composition are allowed to come into play to an ex- tent that is not permitted under the existence of a mote vigorous state. We have thus, it may be con- sidered, an explanation of the common mode of pro- duction of flatulence. From a want of tone at the same time existing in the muscular fibres, an enor- mous distension of the stomach may happen to be permitted. In cases of extreme debility, whether as FLATULENCE. 145 the result of acute or of chronic disease, the accumu- lation of gas that is thus allowed to take place may constitute a formidable condition to deal with. The presence of gas in the alimentary canal must be described as constituting the ordinary condition. It is only when this gas accumulates, so as to occa- sion inconvenience, that a person can be said to be suffering from flatulence. In stomach flatulence a swelling presents itself in the region spoken of as constituting the pit of the stomach. Complaint is made that this part feels tender to the touch, and the clothes are often loosened to obviate the distress occasioned by pressure. The swelling gives a tym- panitic resonant sound on percussion. In proportion as the accumulation advances, the action of the dia- 23hragm becomes impeded, and the breathing embar- rassed ; and from the distension arising, a painful sense of oppression and anxiety is experienced. At- tempts are made to break off" the ^'' wind " by eructa- tion, and immediate relief is obtained when this is accomplished. In popular parlance, a patient in such a state is said to be suflering from " windy spasms." It is especially towards the evening that the dis- tension from flatulence as a simple dyspeptic phe- nomenon is most marked. No decided inconvenience may be experienced during the forepart of the day, but as the evening arrives, and the stomach has been taxed with the work thrown upon it during the day, the flatulent distension with its accompanying dis- tress comes on. With some dyspeptics the flatulence is induced by emptiness of the stomach. A meal, for instance, happening to be delayed a little beyond the 10 146 FLATULENCE. accustomed hour, an attack of "^ wind on the stomach " is the result. In these cases a due regulation of the periods of taking food will often suffice to obviate the complaint. Infants are very subject to flatulence, especially when their natural food is taken too hastily, and when food other than that provided for them by nature is given to them. Mothers and nurses are sufficiently familiar with this infantile trouble, and have their popular remedies for it. The digestive organs are of necessity in a complete state of func- tional inactivity, during intra-uterine life. A call for work is made upon them all of a sudden, and often beyond what is intended by nature, immediately after birth. Now, it is not surprising that a betrayal of weakness should be of common occurrence at this period. The object to be attained in the treatment of flatu- lence is the improvement of the digestive energy and the muscular tone of the stomach. Digestive solution without spontaneous decomposition is what is wanted, and the muscular power should be such as to be capa- ble of expelling by eructation whatever gas may chance to be produced, instead of allowing it to accu- mulate. The food should be easy of digestion, and taken at regular intervals. Vegetable articles, from their difficulty of digestion, are not unlikely to occa- sion flatulence with a weakened stomach. A class of remedies in high repute in flatulence consists of the warm aromatics — or carminatives as they are technically styled. They act in two ways — by exciting muscular contraction, and so effecting an FLATULENCE. 147 expulsion of the flatus that has been generated ; and by checking the occurrence of changes of ordinary fermentation and decomposition in the food contained in the stomach, and so diminishing the subsequent production of gas. The relief that they sometimes afford is so marked and instantaneous, as to have suggested the idea of their acting like a charm, and thus arose the employment of the term carminative (carmen, a charm). The relief, however, produced by carminatives is only likely to be of a temporary nature. To obtain permanent relief a more healthy state of the primce vice must be induced by the reme- dies suggested by a careful consideration of the cir- cumstances of each case. Friction of the abdomen with a stimulating lini- ment will assist the carminative in its action. In extreme cases of tympanitic distension, an injection of assafoetida, turpentine, or rue, may be resorted to. HEAETBURN (CARDIALGIA) By cardialgia or heartburn is commonly understood that burning sensation at the pit of the stomach which is generally attended with the rising or eructation of a small quantity of fluid, of so acrid a character as to produce a most disagreeable sensation, referred to the parts over which it passes, but particularly to the back of the mouth. Often the fluid eructated is not only acrid, but intensely bitter to the taste, and may produce quite a shudder as it rises. It is frequently brought up with an eructation of gas, and may be so small in quantity as not to reach farther than the back of the mouth. Cardialgia occurs at the middle and advanced periods of digestion, and rich living is a common source of its production. Dr. Leared is of opinion that butyric acid either ingested, ready formed, as in pastry, etc., or formed as the result of defective diges- tion, in the stomach, is the agent which gives rise to the sensation ; and in support of his view, he says that pure butyric acid, brought in contact from above with the fauces and oesophagus, produces a sensation pronounced by competent judges to be identical with that of heartburn. I am inclined to think, from per- sonal experience, that certainly the burning sensa- tion at the pit of the stomach is sometimes due to a HEARTBUEN. 149 retrograde flow of bile into tlie cavity of the viscus. After having been subject for some time to a frequent recurrence of the sensation of heartburn, and with it thus fresh before me, I was struck at perceiving the same burning sensation at the pit of the stomach that belongs to it come on during the occurrence of vomit- ing efforts, the result of sea-sickness, after all the food had been some time previously discharged from the stomach. The rejection following the arrival of this burning sensation was strongly tinged with bile, whilst no appearance of bile had been noticed before. The treatment that is usually successful for heart- burn consists of the administration of alkaline agents conjoined with a proper regulation of the quantity and quality of the food. A combination of the carbonate of soda or ammonia with rhubarb and magnesia, or with rhubarb and a mild bitter, as the calumba, may be advantageously given ; or sometimes the liquor potass^ in a bitter infusion. As alkaline agents, the Seltzer, Yichy, and Vals waters form agreeable and useful remedies. Heartburn which is habitual or of long standing is often more effectually relieved by acids than alkalies, and the nitric acid is the best for the purpose. WATER-BRASH (PYROSIS) This constitutes an affection attended with pain, and the eructation of fluid in considerable quantity from the stomach. Dr. Cullen, whose experience of the complaint was large, his field of observation being in Scotland, where it is much more prevalent than in England, has left a faithful description of its phe- nomena. Its paroxysms, he says, " usually come on in the morning and forenoon, when the stomach is empty. The first symptom of it is a pain in the pit of the stomach, with a sense of constriction, as if the stomach were drawn towards the back. The pain is increased by raising the body into an erect posture, and therefore the body is bended forward. The pain is often very severe; and, after continuing for some time, it brings on an eructation of a thin watery fluid in considerable quantity." The fluid discharged is usually almost tasteless, but sometimes more or less acid or sour. Patients often complain that it feels cold as it rises into the mouth, notwithstanding that the pain at the epigastrium which has preceded its eructation is of a burning character. The eructation is repeated several times without at first affording relief to the pain; ulti- mately, however, the pain ceases, and the paroxysm WATER-BRASH. 151 is at an end. The paroxysms vary considerably in duration in different individuals, and likewise the different paroxysms in the same individual. Their period of recurrence is also uncertain. Sometimes, for instance, there may be a paroxysm every day for some time ; whilst at other times the paroxysms occur irregularly at more distant periods. They are un- accompanied with any nausea, retching, or febrile excitement. Pyrosis is an affection especially belonging to the middle period of life. It is seldom encountered in children, and rarely in advanced age. Women are more subject to it than men, and unmarried women than the married. After it has once occurred, it is very apt to return. From its being more common amongst the poor than the rich, the extensive use of farinaceous food has been assigned as one of its ex- citing causes. In Scotland, and some other northern countries — as Norway, Sweden, and Lapland — it con- stitutes a very common complaint — infinitely more so than in England. This is thought to be attributable to the rye, barley, or oatmeal food that is consumed in the place of bread. Nearly half the men and women living near the mountains in Lapland were, according to Linnaeus, in his time, the subjects of pyrosis. The precise nature of the fluid discharged in pyrosis and its source have not been as yet satisfactorily as- certained. Frerichs, from his examination of vomited fluids, has ascertained that in some disorders of the stomach the fluid rejected consists of saliva. The salivary 152 WATER-BRASH. glands, being sjmpathetically irritated, secrete an abundance of saliva, which is swallowed and sub- sequently rejected. The fluid has been found to pre- sent all the characters of saliva in these cases. In reaction it has been^ generally alkaline, but often neutral, rarely acid. It has contained a large quan- tity of the sulphocyanides, and under the requisite conditions has rapidly converted starch into sugar. Montegre, who possessed the faculty of discharg- mg the contents of his stomach at will by eructation, sometimes ejected half a tumblerful of liquid before anything had been taken in the morning. This he looked upon as gastric juice; but it is evident from the properties he described it as possessing, and from what is now known concerning the action of the se- creting follicles of the stomach, that it was not such. He remarked that the rejected fluid differed in reac- tion at different times, acidity being a character that by no means invariably belonged to it ; and that it resembled — in fact seemed identical with, saliva. It evidently consisted of saliva which had been swal- lowed, and had accumulated in the stomach ; and such is doubtless often the source of the fluid matter rejected from the stomach when in an empty state as regards food. The characters of the fluid raised in pyrosis are not those of gastric juice ; but fluid, other than gastric juice, it may be inferred, can be poured out under certain circumstances from the walls of the stomach. In some cases of uremia belonging to Bright's disease, large quantities of fluid are thrown off from the stom- ach by vomiting, which may be presumed to be de- TTATER-BRASH. 153 rived from the stomacli itself. Lehmann says that the rice-water fluid vomited in cholera, both in its physical and chemical properties, is almost perfectly identical with the fluid vomited in uraemia, and that the reaction of these fluids may be either acid, neu- tral, or alkaline. Now, such fluids differ as much from the physiological product of secretion as does that discharged in pyrosis ; and presuming the one to be derived from the stomach, a parallel is offered which renders it not unreasonable to assume that the other may be derived from the stomach also. A catarrhal state of the stomach is sometimes regarded as constituting the condition associated with pyrosis. Bronchorrhoea is an affection attacking the respira- tory mucous surface which presents a close analogy in character to pyrosis. The suggestion that the fluid eructated in pyrosis results from disease of the pancreas, and constitutes a product of secretion of this gland, which has passed by regurgitation into the stomach, seems to me too hypothetical to require any special comment. I have examined some specimens of fluid discharged in cases of pyrosis, with the view of ascertaining if it possessed digestive properties. In one instance the fluid was thrown up, mixed with a little food. It presented a strongly acid reaction, and evidently con- tained a quantity of good gastric juice, as it produced a rapid digestive effect upon the hind legs of a frog suspended in it at the proper temperature. Upon another occasion a portion of two quarts that had been thrown up was examined. As this was only faintly acid, it was treated with strong hj^drochloric 154 TTATER-BRASH. acid in the proportion of twenty minims to the ounce. At the end of six hours there was only slight evidence of digestive action apparent^ which shows that the liquid could have contained scarcely any pepsin. In another instance some fluid was taken that was clear and neutral. It was treated with acid, and at the end of eight hours had only produced a moderate digestive effect. This, therefore, again contained very little active pepsin. In connection with these observations I have per- formed some experiments on the solution and removal of pepsin hy water from the healthy stomach. Forty- eight hours after food had been given to a dog, half a pint of water at the temperature of the body was injected through an oesophageal tube into the stomach. In a quarter of an hour's time the life of the animal was destroyed, and the liquid immediately collected from the stomach. The organ was quite devoid of food, but found to contain a little hair and some small fragments of straw. The liquid presented a strongly acid reaction ; and, experimented upon alone, gave evidence of possessing digestive power. In another experiment, at the same period after the administration of food, six ounces of water at the tem- perature of the body were introduced into the stom- ach, and in five minutes' time the animal was killed. The contents of the stomach, which were immedi- ately collected, were found neutral to test-paper, as also was the mucous surface. Treated with an acid, the liquid obtained produced a strong digestive action in respondence to the test that was employed. In the first experiment it would seem that the water WATER-BRASH. 155 during its quarter of an hour's sojourn in the stomach had excited a little flow of acid secretion from the follicles; whilst in the second, where five minutes only were allowed, pepsin was dissolved out from the mucous surface, but no acid had made its appearance. Pyrosis, as a rule, only constitutes a functional disorder, and is not in itself a grave affection. It sometimes, however, occurs as a concomitant of or- ganic disease, upon the nature of which the gravity of the case will then depend. Persons who have once been affected with pyrosis are very apt to experience a recurrence. Opium is a remedy to which pyrosis generally yields. It relieves the pain ; and, by allaying the morbid irritability of the stomach, checks the exces- sive secretion, which forms the prominent feature of the complaint. Sir Thomas Watson recommends opium in combination with an astringent, and says that the compound kino powder of the London Phar- macopoeia is an admirable remedy for porosis. In the out-patient department of a metropolitan hospital, the physician is frequently called upon to treat this affection, and the jDrescription I am in the habit of ordering at Guy's, and am not disposed to forsake, is one containing opium in combination with a bitter. The following is the formula employed, and such is the success with which it has been used, that I am frequently remarking to students attending in the out- patient room that I have rarely, if ever, known it jfail in rapidly affording relief: R . Liquoris Opii Sedativi, "Xviij ; Inf. Gentiaiife co., 5j. Misce, fiat haustus ter quotidie sumendus. 156 TTATER-BRASH. It often happens that other indications of gastric derangement accompany pyrosis. These will require their appropriate treatment as soon as the pyrosis has been subdued. Any article of food that is known to constitute an exciting cause of the complaint must be abandoned, or the relief afforded by treatment will only be of a temporary description. ACIDITY. Disordered digestion is sometimes attended with acidity of the stomach as its prominent symptom. The person experiences, in some instances, occasion- ally only, in others almost constantly, a sour taste in the mouth. Acid eructations occur whilst digestion is going on, and the acidity of these eructations may be such as to set the teeth on edge. If the condition exists for some time, the teeth indeed become acted on and destroyed. Everything that is taken may be found to " turn more or less sour on the stomach ;" but it is discovered that some articles of food are more productive of acidity than others. Vegetables, pastry, sweets, and fruit, for example, are of this class. It sometimes happens that it is only after partaking of articles of this kind that the acidity is experienced. In the gouty diathesis a predisposition exists to the occurrence of this derangement. It is well known that the saccharine principle is convertible by a particular kind of fermentation into acid. This conversion being permitted to occur within the stomach, through the existence of a de- fective state of its secretion, will account for some of the acid generated : namely, that which is specially produced by food of a saccharine and farinaceous de- scription. But marked acidity is in some cases ex- 158 ACIDITY. perienccd after the exclusive consumption of animal food ; and hence it must be inferred that an exces- sive elimination of acid as the result of secretion may constitute also a source of the complaint. Under healthy circumstances, changes of ordinary fermentation and putrefaction are not permitted to take place within the stomach, on account of the antiseptic ^^ower which the gastric juice enjoys; but when gastric juice imperfect in quality or deficient in quantity is secreted, fermentative changes in the food fail to be prevented from occurring ; and so, the production of acid results. Again, from obstruction in the neighborhood of the pylorus, or from some other cause, the food may be delayed for too long a time within the stomach, and the generation of acid that w^ould not otherwise have taken place be per- mitted. A morbid irritation of the stomach arising from disease, as from ulcer or cancer, or from the presence of indigestible articles within its cavity, may lead to an undue action of the secreting apparatus ; and thus, an excessive outpouring of acid. The irritation re- sulting from disease may even cause gastric juice to be secreted during an empty state of the organ. Fur- ther, a source of irritation existing in some other j)art may affect the stomach in a reflex manner, and cause, like direct irritation of the organ, a flow of gastric juice to take place without the usual stimulus being supplied. Such, for example, has been found to occur during the passage of gall-stones through the bile- ducts; and in the gastric disorder so common in ACIDITY. 159 organic diseases of the brain and tubercular disease of the lungs. Alkalies and the alkaline earths — as the carbonates of soda, potash, and lithia ; magnesia ; and lime-water — taken about two or three hours after a meal, by neutralizing the excess of acid existing, afford a tem- porary relief to the complaint. The fluid magnesia (Liq. Magnesiae Carbonatis of the British Pharmaco- poeia) forms an agreeable and serviceable antacid. The Vichy, Yal^, Seltzer, and lithia waters, may often also be advantageously resorted to. By the continued administration of these remedies, a perma- nent removal of the morbid condition may be often- times brought about, but in other cases a temporary relief is all that continues to be afibrded ] and there are many persons who are constantly in the habit of resorting to the use of the carbonate of soda, which is the popular remedy employed, to correct their acidity of stomach. Where the alkaline treatment fails, the mineral acids, by acting as tonics and improving the digestive power, will sometimes effect a cure. The nitric acid in particular, says Abercrombie, is often found to be one of the best correctors of acidity. Where gout exists, colchicum is likely to do good. As in the treatment of the other manifestations of deranged digestion, attention must be paid to the food and drink that are taken. A careful regimen will often succeed by itself in removing, and, if it do not succeed in removing, will always lessen the complaint. Vegetables, fruit, pastry, and sweets, being the arti- cles most productive of acidity, are to be looked upon 160 ACIDITY as the things particularly to be avoided. Toasted and pulled bread agree better than bread of the ordinary form. Of animal food, broths and soups are the most likely to turn sour on the stomach. Dry sherry and brandy and water form the liquids the least likely to disagree. Sweet ales and imperfectly fermented wines are almost sure to provoke an aggravation of the com- plaint. INTESTINAL DIGESTION. The agents concerned in intestinal digestion are the parts belonging to the intestinal canal, and the secretions of two large glands — the pancreas and the liver. The intestine completes the alimentary canal be- low the stomach. It is physiologically and anatomi- cally divided by a valvular orifice (ileo-csecal) into two portions, named, from their difference in size, the small and large intestine. The small intestine forms the upper and considerably the longer portion of the two. It measures, in the adult human subject, about twenty feet in length. It is disposed in coils or con- volutions in the centre of the abdomen, and attached in front of the spine by a process of peritoneum called the mesentery. The large intestine measures about fiYe feet in length. Beginning at the right iliac fossa, it passes round the abdomen, describing a horseshoe shaped bend around the convolutions of the small in- testine occupying the middle of the abdomen. The small intestine presents a regular or uniform surface, a character by which it is distinguishable at a glance from the large. Anatomists subdivide it into three portions, named respectively, proceeding from above downwards, the clicodemun, and jejunum, and ileum. 11 162 INTESTINAL DIGESTION. The duodenum is the shortest and widest of the three subdivisions. It only measures about ten inches in length, which is equivalent to twelve finger breadths — from which has arisen the name it bears. In its course it receives the secretions of the liver and pan- creas, and its walls are occupied with little compound glandular structures, called the duodenal or Brunner's glands. These duodenal or Brunner's glands exist only in this portion of the intestine. The jejunum forms the continuation of the intes- tine next below the duodenum. It is so called from its being generally found in an empty condition after death. About the two upper fifths of the small in- testine below the duodenum are considered to belong to the jejunum ; but no definite character exists to give a line of demarcation between the jejunum and the ileum, or the portion of intestine below. In the case of jejunum and duodenum there is also an ab- sence of any superficial mark of distinction ; but Brunner's glands, it may be considered, afibrd the means of assigning a natural boundary line between the two. The ileum is so named from its numerous coils or convolutions. Continuous with the jejunum above, it completes the small intestine and terminates abruptly in the large intestine below at the ileo-ca^cal valve. The large intestine in diameter considerably ex- ceeds that of the small. Its longitudinal fibres are collected into three bands, which, being shorter than the intestine itself, give rise to the puckered or sac- culated appearance it presents. It begins at the right iliac fossa in a pouch or cul-de-sac, which ex- THE INTESTINE. 163 tends down below, the entrance of the ileum, and is named the caecum. Given off from the lower end of this pouch is a little process called the appendix cceci, or, sometimes, from its resemblance to a worm, ap- pendix vermiformis. A fine canal runs through the centre of this process, and opens into the caecum. Sometimes extraneous matter becomes impacted in this canal, and sets up ulceration, which may lead to perforation, peritonitis, and death ; or through ad- hesive inflammation, it may become affixed to some portion or other of the abdominal parietes or contents, and leave a ring-like opening, through which a coil of intestine at some subsequent period may work down, and become strangulated and produce death. It contains a number of glands similar to those ex- isting in the caecum. No other function can be as- signed to it than that of forming a glandular process, and it constitutes a structure that is almost peculiar to man. Above the caecum comes the colon. This consti- tutes the principal portion of the large intestine. Starting at the right iliac fossa, it describes a curve round the abdomen ; first ascending on the right side, next passing across, then descending on the left side, and, finally, before ending in the rectum, presenting a double bend upon itself, after the manner of the letter S, in the left iliac fossa. From the difterent directions taken, ascending, transverse, descending, and sigmoid flexure, portions of the colon are enume- rated. The remainder of the large intestine is called the rectum. This carries the intestine through the pelvic cavity to its terminal orifice at the anus. 1G4 INTESTINAL DIGESTION. The sigmoid turn taken by the colon before ending in the rectum, supported as it is by the left iliac fossa, maj' be looked upon as forming a convenient provision for the accumulation of fecal matter during the inter- vals of its evacuation from the intestine, so as to spare the walls of the rectum and the sphincter fibres of the anus from the strain and weight that would other- wise, by an absence of the arrangement, be thrown upon them. The ileo-caecal valve is placed at the junction of the small with the large intestine. It is composed of a pair of semilunar-shaped folds, which project towards the cavity of the caBCum, and leave a narrow elliptical-shaped opening between them. From the position the segments of the valve occupy, a free passage is allowed from the ileum to the ca?cum, or in a downward direction ; but when pressure is ap- plied on the opposite side the segments are brought into apposition, and the orifice is closed. Thus a backward course from the large into the small intes- tine is by the ileo-csecal valve prevented. The walls of the intestine are composed of the same number of coats as the stomach. Externally is an investment of serous membrane derived from the peritoneum or large serous sac of the abdomen. Next comes the muscular coat, then a layer of areo- lar tissue constituting the submucous coat, and after- wards the mucous coat, by which the free internal surface is formed. The muscular and mucous coats will each require some words of special reference to be made concerning them. The muscular fibres are, like those of the stomach, PERISTALTIC MOVEMENT OF INTESTINE. 165 of the simple or non-striated kind. They are arranged in two hiyers, the inner Layer consisting of circuLar, the outer of longitudinal fibres. By these two sets of fibres the peristaltic movement, as it is called, which the intestine undergoes, is produced. Succes- sive waves of contraction, followed by relaxation, pass along the canal, and occasion an undulatory or vermicular kind of movement. Thus the alimentary matter is urged onwards over the intestinal surface, absorption of its nutrient portion taking place, and the excrementitious residue being conveyed to the lower extremity of the alimentary canal, ready for expulsion from the system whenever it may be de- sired. The movement observed in the intestine when the abdomen of an animal is opened immediately after death, is by no means to be taken as a correct repre- sentation of that which is naturally occurring during life. The idea given on w^atching the exposed intes- tine in a recently killed animal is that the coils in their movement resemble a bundle of worms actively writhinsc in and out. What is here seen, however, forms a highly exaggerated representation of the movement that naturally occurs ; and in it, also, there is a want of regularity and of any show of design. In the action that takes place during life there is a definite, slow, rhythmic movement, which gradually propels the intestinal contents downwards through the canal. By an increased activity of movement, such as may be brought about by the presence of irri- tating matter in contact with the mucous surface; and, in some dispositions, by the influence of a men- 166 INTESTINAL DIGESTION. tal shock or impression, the intestinal contents may be urged too rapidly along the canal, and diarrhoea thereby produced. It has been suggested that the contact of air is the cause of the excited movement of the intestine which is seen when the abdomen is opened immediately after death. This, however, cannot form the true expla- nation, because it may be noticed without exposure to the air being made. If the belly of a rabbit, for instance, be watched whilst the animal is alive, the movement of the intestine is not to be, or scarcely to be, perceived. Let it be watched, however, imme- diately after death, and a vigorous movement is to be recognized through the abdominal walls without any opening into the abdominal cavity having been made. Exposure of the intestine also, during life, does not excite that exalted peristalsis which is observable after death. Schiff asserts that the exalted action is due to the influence of the stoppage of the flow of blood on the muscular fibres. He says, as active intestinal con- tractions may be induced by compressing the abdomi- nal aorta during life as what occur after death ; and that on removal of the compression the excited ac- tion disappears. Bernard states that the excited peristalsis, taking place as the result of death, may be subdued by re-establishing the circulation hy the performance of artificial respiration, and that its re- appearance is noticed when the artificial respiration is stopped. This is in harmony with Schifl"s asser- tion ; but it is to be remarked that other circum- stances besides the stoppage of the circulation are FECAL VOMITING. 167 capable of inducing the phenomenon, for Bernard has noticed it after division of the spinal cord between the origin of the cervical and brachial plexuses ; and I have witnessed its production by the injection of carbonate of soda into the circulatory system. When an obstruction exists in any part of the small intestine, a backward flow of its contents takes place towards the stomach; and what is called fecal vomiting is induced. It is only the contents of the small intestine that can be thus returned into the stomach and ejected by the mouth, as the ileo-C£ecal valve would oifer a complete barrier to a backward flow from the large intestine into the small. The backward flow which occurs with fecal vomit- ing was formerly put dowm as attributable to an in- verted action of the muscular fibres of the intestine — an anti-peristalsis ; but Dr. Brinton has shown that another explanation, and one which does not involve any inverted muscular action, can be given. Peri- stalsis, he says, in an obstructed tube distended with fluid, produces a double current — a forward move- ment at the periphery, and a backward one in the centre or axis of the canal. The muscular fibres, acting in a downward direction, and with a force pro- portionate to the resistance that is to be overcome, propel the intestinal contents to the seat of obstruc- tion, whence they must take the course that ofiers the least amount of impediment to their progress. This is a backward one along the centre or axis of the canal, or the position most remote from that at which the downward propelling influence of the in- testinal muscular fibres is exerted upon the contents 168 IXTESTIXAL DIGESTION. of the canal. Thus, by the ordinary downward peri- staltic action the reflux of matters from the seat of obstruction in a strangulated intestine through the part above into the stomach can be accounted for. Their subsequent ejection from the stomach completes the train of phenomena concerned in fecal vomiting. The muscular fibres of the intestine are all of the plain or non-striated kind. Their nervous supply is derived from the sympathetic sj'stem, and in their action, therefore, they are not under the obedience of the will. At the lower extremity of the canal fibres of the striated kind are provided to govern the outlet. These are supplied from the cerebro-spinal system, and placed under the controlling influence of the will. The mucous coat of the intestine presents charac- teristic peculiarities in different portions of the canal. In elementary constitution it resembles other mucous membranes. Its epithelium, like that of the stomach, is of the columnar variety. A layer of smooth or un- striped muscular fibres has been described by Brlicke as existing in its deeper part. These muscular fibres of the mucous membrane are quite independent of those which have been described as forming the mus- cular coat. In man their slight development renders it often very difficult to discover them ; but in ani- mals where they are well developed, two sets, longi- tudinal and transverse, are stated to have been found. The structures belonging to the mucous coat calling for examination are certain projections — valvulaecon- niventes and villi ; and glands of various kinds, viz., Brunner's glands, follicles of Lieberkuhn, solitary glands, and Peyer's patches. THE VALYULyE CONNIVENTES. 169 The valvulae conniventes consist of closely packed, transverse, crescentic-sliaped folds of mucous mem- brane, projecting into the cavity of the canal. Un- like the folds of mucous membrane met with in the stomach and oesophagus, these are permanent inflec- tions : no distension to which the intestine can be subjected leading to their obliteration. They belong only to the small intestine, and are not encountered throughout the whole length of this. Beginning about an inch, or rather more, below the pylorus, they extend through the remainder of the duodenum, the jejunum, and about the upper half of the ileum. They attain their largest dimensions in the duodenum and jejunum. In the ileum they gradually diminish in size, as it is traced down, until about the middle of it, when they entirely disappear. The largest measure from a quarter to half an inch in breadth across the centre, which is their widest part, and in length they may nearly encircle the bowel. Floating in the intestinal canal, and bathed by its contents, the valvulse conniventes will have the effect of materially increasing the extent of surflice for the absorption of nutrient matter. At the same time, projecting into the canal, as they do, they will, to a certain extent, delay the alimentary matters in con- tact with the absorbing surface, and so tend to render the process of absorption more complete. These val- vulge conniventes are said to be peculiar to the human subject. The villi constitute important absorbing organs. They consist of minute projecting processes, so thickly studding the mucous surface as to give to it, where 170 INTESTINAL DIGESTION. they exist, a velvety appearance. They are struc- tures that belong only to the small intestine. Be- ginning at the upper part of the duodenum, they extend down over the whole surface of the small in- testine, clothing the valvulas conniventes in their course, and come to an abrupt termination at the free edge of the ileo-caecal valve. Thus, the surface of the valve directed towards the ileum is covered w4th, wdiilst that directed towards the caecum is de- void of, villi. Much variety exists in the shape and size of the villi of different animals. Considerable variation is also observable in the different villi, as they are seen upon the intestine of the human subject; but their usual form may be said to consist of more or less flat- tened cones. They are of sufficient size to be visible to the naked eye, and are best viewed by placing the mucous membrane under water, when they float and stand apart from each other. The villi constitute little solid processes formed out of the elements of the mucous membrane. Each consists of a central portion or basis covered with an investing layer of epithelium. In the substance of the villus there are found bloodvessels, a branch of the lacteal system, and some unstriped muscular element, lying in a stream or basis of fibrous material, and sur- rounded by basement membrane, wdiicli supports the investing epithelial layer. Nerves have not as yet been recognized in the villi. The bloodvessels of the villi are exceedingly nu- merous. Small arteries pass up into the process, and terminate in a close network of capillaries placed im- THE VILLI. 171 mediately beneath the basement membrane. After traversing the capiUaries, the blood is returned from the villus usually by a single vein, which forms one of the tributary sources of the portal system. By means of these bloodvessels, substances of a soluble and diffusible nature are taken up from the intestine and carried to the liver. Their great vascularity renders the villi exceedingly beautiful microscopic objects in injected preparations. A branch of the lacteal system for conveying away the product of special absorption, passes through the centre of the villus and escapes at its base. In what way it commences at the free extremity of the villus, has not as yet been satisfactorily made out. During intestinal digestion the villi are charged with chyle, and thereby rendered opaquely white. They now give a dense white character to the mucous surface, wdiich it does not present at other times. The muscular element was first recognized in the villi by Brlicke. It consists of a thin layer of longi- tudinal fibres arranged immediately around the cen- tral lacteal. It is, no doubt, derived from that gen- eral expanse of unstriped muscular tissue which has been somew^hat recently found to pervade the whole mucous membrane of the alimentary canal. The cor- rugation of the villi and the retraction of their sub- stance from their epithelial covering — appearances to be observed on examining the intestine immediately after death — form conditions produced by the con- traction of this tissue. It is asserted that contrac- tions have been witnessed in the villi during life, and it has been suo:o;ested that such contractions function- 172 INTESTINAL DIGESTION. ally take place, and fulfil the purpose of forcing on the chyle through the lacteal of the villus. The matrix of the villi consists of indistinctly marked fibrous tissue. Although presenting but ob- scurely marked structural characters, Kolliker says it must undoubtedly be regarded as a metamorphosed connective tissue, without anv admixture of elastic element. The basement membrane forms a layer of j)erfectly homogeneous material which surrounds the structures that have been already described. It supports the epithelial investment, and is continuous with the same structure belonging to the general mucous sur- face of the intestinal tract. The epithelial investment of the villus is composed of a single layer of columnar or club-shaped particles, which rest with their pointed extremities downwards upon the basement membrane. Their other extrem- ities, which are flat, form the free surface of the vil- lus, and being evenly packed together give rise to the production of a pavement-like appearance. Each cell is provided with an oval-shaped nucleus. It was formerly stated by Good sir that the villi be- came deprived of their epithelial investment at the commencement of intestinal digestion, and remained in that state till the process of digestion was com- pleted. He considered that by this shedding of its epithelium, through which the villus would lie naked amongst the intestinal contents, a more favorable con- dition was presented for the process of absorption. Digestion being at an end, and absorption no longer THE VILLI. 173 going on, the villus was said to again acquire its pro- tective coating of epithelial particles. It is not difficult to show that this representation of Goodsir is erroneous, and to point out the fallacious ground upon which it was founded. The absorbing as well as the non-absorbing villus is in reality cov- ered with epithelium, as may be seen by conducting the examination immedkdely after death. If, however, whilst digestion is being carried on, a short period only be allowed to elapse after death, before the ex- amination is made, the villi will be found in a more or less denuded state. Within an astonishingly short space of time, indeed, the epithelium begins to fall away after death, and leave the basement membrane of the villus exposed. At first, the epithelial parti- cles adhere together in clustered masses as they are shed, but ultimately they all fall apart, and then the examination displays a naked villus lying in an epi- thelial debris, or mass of isolated epithelial particles. It seems as though the juices present in the intes- tine at a period of digestion possessed the power of acting on the epithelial layer immediately after the extinction of life, so as to bring about the disintegra- tion noticed. According to the observations I have conducted, the epithelium is not in the same way rapidly thrown off when death has taken place at a period of fasting, but may be found attached many hours afterwards. Thus, the statement of Goodsir can be reconciled, and an illustration is afforded of how necessary it is in forming conclusions about conditions belonging to life from what is observed after death, to guard 174 INTESTINAL DIGESTION. against being misled by the results of post-mortem change. Instead of the epithelial investment of the villus being shed during absorption, it seems, indeed, to constitute the agency by which its special absorbing function is exerted. It appears, for instance, to be the epithelial cells covering the villus that pick out the constituents of the chyle from the intestinal con- tents. For this, the cells must be endowed with the power of drawing within them certain materials from the alimentary matter around and rejecting others, just as the secreting cells of glands are found to select from the various constituents of the blood the appro- priate elements for the formation of the different se- cretions. Whilst absorption is going on, the epithelial cells are to be seen charged with fat-particles, which they have evidently drawn from the intestinal con- tents. These they, in some manner or other, not as yet satisfactorily made out, discharge into the central lacteal of the villus, to form the fatty element of the chyle. During the process of absorption many of the cells are observed to assume more or less of a spher- oidal form. Cells, however, presenting their ordinary columnar shape, are also to be seen charged with fat, and must therefore be looked upon as likewise taking part in the absorbing process. Looking now to the glandular structures of the in- testine, what are called Brunner's glands are the first to which I will direct attention. These belong to the upper part of the intestine or duodenum ; hence the name " duodenal glands," by which they are also known. They are open glands, and in their minute THE INTESTINAL GLANDS. 175 anatomy exactly correspond with the pancreas. There is only this difference, indeed, between the pancreas and Brunner's glands, — the former consists of lobules aggregated together into a circumscribed mass around a common duct ; whilst the latter consist of lobules spread out in an isolated manner, beneath an extended surface, each little glandular mass being provided with an independent duct, through which the secretion is discharged into the alimentary canal. The extent of these glands may be looked upon as affording a means of anatomically defining the limits of the duodenum. They also give to it a physiologi- cal character of distinction from the remainder of the small intestine. Near the pylorus, wdiere they are most numerous, they are so closely clustered together as to form a compact glandular layer in the submucous tissue, and are here from one-eighth to one-tenth of an inch in diameter. Followed downwards through the duodenum, they become smaller and more and more scattered, until they cease altogether. The lit- tle duct with which each glandular mass is provided dips through the mucous membrane from the surface, and, after branching repeatedly, terminates in vesicu- lar dilatations, which are lined with the secreting cells. Brunner's glands are found to be more highly developed in the herbivorous than in the carnivorous animal. The secretion of Brunner's glands, on account of their anatomical disposition, cannot be obtained in a pure or unmixed form. Nothing, therefore, can be said regarding its propertiesbeyond that it is a color- less and apparently a viscid and alkaline fluid. For 176 INTESTINAL DIGESTION. the same reason its physiological action cannot with certainty be mentioned, but it probably agrees with the secretion of the pancreas in the functions it dis- charges. Lieberklihn's follicles exist throughout the whole length of both the small and large intestine. They consist of small, simple, straight tubules, thickly set in the mucous membrane perpendicularly to its sur- f[ice. Each tubule is open above and terminates be- low in a closed rounded extremity ; or, occasionally, it appears to bifurcate into two. In length they cor- respond to the thickness of the mucous membrane. They are lined with a layer of epithelial cells similar to those investing the villi, and therefore of the cy- lindrical or columnar-shaped variety. Closely packed together as they are, and extend- ing: throuoiiout the whole lenirth of the intestine as they do, an infinite number of these tubules exist. Looked at singly, they appear insignificant, but viewed collectively it is evident that they must constitute an important apparatus. Their secretion cannot be col- lected in an unmixed form, and nothing can be de- finitelv stated with reo:ard to its amount. Thus much, however, ma}^ be said respecting its properties, namely, that it constitutes a clear, colorless, and strongly alkaline fluid, endowed with the power of actively transforming starch into sugar. It forms the chief constituent of what is called " intestinal juice." The solitary glands consist of closed sacs having a flask-shaped form, with the pointed extremity di- rected upwards. They lie imbedded in the mucous membrane, and when in a state of repletion are of THE INTESTINAL GLANDS. 177 about the size of a mustard seed. They may then be readily seen by holding the intestine up towards the light, but in an empty state they are not easily dis- coverable. Their contents, consisting of a soft, pulpy, semi-transparent, grayish-colored material, must be looked upon as constituting a product of secretion. The elementary constituents of this material displayed by the microscope consist of nuclei, cells, and granular matter. The solitary glands are found scattered here and there along the whole length of the intestine, includ- ing its small and large divisions. They exist in large number in the appendix of the caecum, and are more numerous in the large than in the small intestine. Their number, however, is very various in different individuals, sometimes not a single one being discov- erable throughout the whole small intestine, whilst at other times they are found there in considerable quantity. The mucous surface, with its projecting villi, is traceable over them in an uninterrupted man- ner in the small intestime. In the large, the glands are of greater size, and upon each of the little promi- nences upon the surface created by their presence there is a small aperture which leads to a little pit or depression in the mucous membrane. The existence of these depressions formerly led to the notion that the solitary glands of the large intestine differed from those of the small (over which no such depressions ordinarily exist), in being provided with an opening communicating with the surface. The appearance of an opening, however, is fallacious, for at the bot- tom of the depression the follicle is to be found in a 12 178 INTESTINAL DIGESTION. closed condition like that existing in the small intes- tine. Pej'er's patches are simply collections of solitary glands clustered together into circuhar, oval, or oblong- shaped patches. They are met with only in the small intestine, and are invariably situated on that part of the intestine which is most remote from its mesen- teric attachment. Upon an average, about twenty of these patches are found to exist. They increase in size as they are traced downwards, and in the lower part of the ileum may measure in their long diameter, which runs lengthways in the intestine, as much as from two to four inches, whilst in the jejunum their greatest measurement may not be more than half an inch. These patches are not only, as has just been mentioned, larger, but are also more numerous, in the ileum than elsewhere ; indeed, it is to this part of the intestine that they may be considered particularly to belong. The number of solitary glands in a patch may vary from 20 or 30 to 100 or 200, according to its extent. Pej^er's patches are more developed in carnivorous than in herbivorous animals. Little can be said about the function of the closed follicles of which the solitary glands and Peyer's 23atches are formed. What they contain must be re- garded as a product of secretion; but whether this is destined for return into the system by reabsorption, or for discharge into the intestine by rupture, has constituted a matter of dispute. Being larger during digestion than fasting, the former may be considered to constitute their period of greatest functional ac- tivity. There are grounds for regarding the material THE INTESTINAL JUICE. 179 which gives the characteristic odor to the faeces as a product of elimination from the system by these ghmds. In typhoid fever they are found to be speci- fically affected, and thus arises the ulceration of the intestine that forms so frequent an accompaniment of this disease. In phthisis also they are prone to be- come the seat of tubercular deposit; and this deposit, leading to ulceration, accounts for the colliquative diarrhoea from which phthisical patients so often suffer in the latter stage of the complaint. The mixed secretion from the glandular structures of the mucous membrane of the intestine constitutes what is called ^^ntestinal juice." Frerichs procured the intestinal juice by placing a couple of ligatures on a coil of intestine at a period of fasting, and, from four to six hours afterwards, collecting what had ac- cumulated between them. Bidder and Schmidt pre- vented the flow of bile and pancreatic juice into the alimentary canal, and established a fistulous oj^ening in the small intestine, about one-third of its distance down. They afterwards collected the secretion that escaped from the intestine through the fistulous open- ing that had been made. It cannot be considered that by either of these processes a perfectly natural intestinal juice has been procured. Thus much, how- ever, may probably be stated as regards its properties, viz., that it constitutes a colorless, viscid, alkaline fluid, endowed with the power of converting starch into sugar and of emulsifying fatty matter. Experiment seems to show that the intestinal juice is also capable of exerting a solvent influence upon nitrogenized substances. Bidder and Schmidt found 180 INTESTINAL DIGESTION. that meat and coagulated albumen placed in a muslin bair, and introduced into the small intestine whilst in an empty state, and with a ligature applied above to prevent the descent of bile and pancreatic juice, gave evidence in four to six hours' time of a consider- able amount of digestive action having occurred. In an experiment performed b}^ myself, the hind legs of a frog, which had been similarly introduced into the intestine, were found, at the end of six hours' time, in a partial state of digestion ; a portion of the skin, for instance, hating been dissolved away, the muscles underneath separated, and some of the bones to a slight extent exposed. Little is known about the secretion of the lars^e intestine beyond that it presents, like that of the small, an alkaline reaction. The secretion of the csecum forms no exception to this, although from what is observed in some animals a contrary con- clusion might be arrived at. The strongly acid re- action, however, often found to be presented by the contents of the caecum does not depend upon an acid secretion being poured out, but upon the changes that occur amongst the contents themselves. To complete the examination of the agents con- cerned in intestinal digestion, two important glands remain to be referred to — the pancreas and the liver. The pancreas — or sweetbread, as it is popularly styled — is a gland that presents an elongated flat- tened form. It stretches across from one side of the upper part of the abdomen to the other, close in front of the spinal column. The left extremity is pointed, and constitutes what is called by anatomists the tail THE PANCREAS. 181 of the gland. At the other extremity an enlarge- ment exists, which is embraced by the curvature of the duodenum. This is called the head. Altogether, the gland presents a somewhat hammer-like form. In appearance, the glandular tissue of the pancreas resembles that of the salivary glands, and there is also a corresponding resemblance in their minute anatomy. It is conspicuously lobulated upon its ex- terior, and also throughout its substance. It is un- provided with any distinct capsular investment, but surrounded by areolar tissue, which dips down be- tween and connects the lobules. Its duct — the canal of Wirsung — courses through it from left to right, in a central position, gradually increasing in size as tributary branches join it on its way. After escaping from the gland it arrives in contiguity with the bile- duct, the two afterwards passing obliquely through the coats of the duodenum to terminate in a joint opening upon the summit of a little papillary eleva- tion observable upon the mucous surface about three or four inches below the pylorus. Usually, it would seem, a second duct springing from the head of the gland opens into the duodenum a little lower down. Sometimes this throws itself instead into the prin- cipal canal ; but since attention has been directed to the point by the dissections of Bernard, it has been found that the former condition prevails so frequently as to constitute the ordinary instead of, as formerly considered, the exceptional state. In ultimate elementary structure the pancreas ex- actly resembles the salivary glands. The lobules of which the organ is made up form but repetitions the 182 INTESTINAL DIGESTION. one of another. The lobular ducts join together, and these, again coalescing, ultimately form the principal duct of the gland. Reversing the description, and tracing these ducts in the opposite direction, after dividing and subdividing until they have become reduced to exceedingly small dimensions, they are found to terminate in clusters of vesicular dilatations consisting of basement membrane lined with secretory epithelium. Around these vesicular terminations of the duct, capillary bloodvessels are arranged in a plexiform manner, and afford the supply from which the elements of secretion are drawn. The secretion of the pancreas, or pancreatic juice, has been collected from various animals direct from the duct ; and thus, precise language can be employed regarding its characters, properties, and use. It is only temporarily, however — onlj' for two or three days after the operation that is required to be made has been performed — that the secretion can be ob- tained, on account of the canula introduced into the duct setting up ulcerative action, which causes it to loosen and come away. Then, in the course of a short time, through nature's efforts, the duct becomes reformed, and the flow of secretion takes place into the intestine as before. It is to Bernard's investi- gations that we are indebted for most of the knowl- edge we possess regarding the physiological attributes of the pancreatic juice. My own experimental ex- perience, however, enables me to testify to the accu- racy of what is about to be stated upon the subject. As with the saliva and gastric juice, it is only when its presence is required that tlie pancreatic juice flows THE PANCREATIC JUICE. 183 into the intestine. At a period of fasting no discharge of secretion takes phace from the ghand. Shortly after food has been ingested, however, pancreatic juice be- gins to flow, and continues to escape as long as the process of digestion is being carried on. Pancreatic juice, when in a normal state, consti- tutes a transparent, colorless, odorless, and viscid liquid, with a slightly saline taste and a decidedly al- kaline reaction. Exposed to heat, it coagulates to a solid consistence, from the large quantity of a kind of albuminoid matter it contains. As with albumen, a coagulation is also formed by alcohol and the mineral acids. Although thus closely allied to albumen, still the coagulable principle of the pancreatic juice is not strictly identical with it, for it forms the active con- stituent of the secretion, and so possesses properties which albumen does not. The pancreatic juice which is first collected, when the operation is performed shortly after the ingestion of food, and has turned out satisfactorily, is viscid, and richly charged with the above-mentioned coagu- lable principle. That which flows later is poorer, or more watery ; and finally, before the canula introduced into the duct comes away, a fluid may escape no longer enjoying the power belonging to the normal secretion. With this deterioration in the quality of the secretion the alkaline reaction becomes more in- tense, and the addition of an acid now determines a marked effervescence from the amount of alkaline carbonate present. Pancreatin is the name given to the albuminoid material which endows the pancreatic juice with the 184 INTESTINAL DIGESTION. physiological properties it enjoys. This material was formerly confounded with albumen, but there is a chemical as well as a physiological difference between the two ; for after having been precipitated by alco- hol, pancreatin is redissolved by water, and a fluid possessing the power enjoyed by the pancreatic juice is obtained. It was discovered by Tiedemann and Gmelin that the pancreatic juice is reddened by an aqueous solu- tion of chlorine, and Bernard has shown that its effect is due to the presence of pancreatin. It is not with the perfectly fresh juice that the solution of chlorine reacts, but only after a change has taken place by keeping. When decomposition, however, is advanced, chlorine is found no longer efficacious in developing the color, but now nitric acid will produce it instead. A watery infusion of the substance of the pancreas behaves in this respect in the same way as the secre- tion. Neither bile, nor saliva, nor gastric juice amongst the digestive liquids gives rise to this reaction ; but, according to Bernard, the liver, spleen, and lymphatic glands, yield infusions which, like that of the pan- creas, are reddened by chlorine. Nothing, I am of opinion, can be definitely said about the quantity of pancreatic juice normally se- creted, for it can scarcely be conceived that the action of the gland can escape being prejudicially influenced hy the operation to which the animal has necessarily to be subjected for the process of collection. In speaking of the physiological action of the pan- creatic juice, there are three points of view under THE PANCREATIC JUICE. 185 which it will have to be looked at : these are, the ac- tion it has the power of exerting upon — 1. Starch, 2. Fat, and 3. Albuminous materials. The pancreatic juice possesses the power of rapidly transforming starch into sugar, and physiologists are all of accord in assigning to it this as one of its func- tions. Starch must be transformed before it can be of service to the animal being. Kemaining as starch, it would simply pass through the alimentary canal, and thus prove a useless material to the system, be- cause it altogether resists absorption. The saliva, in the case of the human subject, certainly also possesses the power of rapidly converting starch into sugar ; but, as pointed out under the head of that secretion, the conditions under which it is placed are so unfa- vorable for the exercise of the endowment in question that it cannot be possible for much action to occur. With the pancreatic juice, however, the surrounding circumstances are all in the highest degree favorable for the exercise of its transformative influence. The food, for example, has been reduced to a semi-liquid state before reaching the duodenum, where its ad- mixture with the pancreatic juice takes place. The two then are urged slowly along the intestinal canal by the peristaltic movement that occurs, and thus cannot fail to become thoroughly incorporated to- gether. Brought and delayed in this manner in con- tact with each other, and also exposed to the elevated and equable temperature existing in the interior of the bodv. the most favorable circumstances are of- 186 INTESTINAL DIGESTION. ferecl for the occurrence of metamorphosis. As the transformation is effected the sugar produced is ab- sorbed by the bloodvessels and carried to the liver, where a further change of an assimilative nature is effected. The next office of the pancreatic juice to be spoken of is that connected with the digestion of fat. Eberle, it appears, was the first to announce, which he did as far back as 1834, that the pancreas possessed the power of emulsifj'ing fat. He experimented, how- ever, only with the glandular tissue of the organ, and never obtained its secretion. His announcement also could not have received much attention, as it is not until after the publication, in 1848, of Bernard's ex- tensive series of experiments, commenced in 1846, that the pancreas is found to be spoken of by physi- ologists in connection with the digestion of fat. Be- fore Bernard's researches nothing was known about the nature of the pancreatic secretion, and nothing had been shown to connect it with the digestion of fat. Bernard is therefore fairly entitled to the credit of discovering the function of the pancreas now about to be referred to. It appears that Bernard was led to the prosecution of his researches upon this subject through observing, whilst conducting some experiments for the purpose of comparing the phenomena of digestion in the ani- mal and vegetable feeder, that after the ingestion of fat the lacteals coming from the intestine almost up to the pjdorus were found to be injected with milky chyle in the dog, whilst in the rabbit chyle only made its appearance in the lacteals some little distance THE PANCREATIC JUICE. 187 down. With this, he noticed a corresponding differ- ence in the point of discharge of pancreatic juice into the intestine, and thus was prompted, whilst seeking for an exphanation of the phenomenon, to give atten- tion to the pancreas. In this manner he was led to endeavor to collect the pancreatic juice, and, having succeeded in this, to examine its action upon fat. The effect produced when pancreatic juice is freely shaken with oil or fat is to form a liquid having the appearance of milk. The pancreatic juice emulsifies or brings the fatty body into a minutely divided state ; in which it afterwards remains suspended in the liquid in the same manner as is noticed in milk. The minute globules into which the fat has been sep- arated have no disposition again to coalesce and rise and form an oily laj^er at the surface, as they do when saliva or any ordinary watery liquid may happen to have been used instead. In this state of minute sub- division the fatty matter is found to be adapted for absorption and passage into the lac teals, the effect of its presence in the lacteals being to give to their con- tents a milky character, which they do not possess when no absorption of fat is going on. So far, the action of the pancreatic juice on fatty matter is only one of a physical kind ; but if the emul- sion be placed aside for a few hours a chemical change will be found also to have taken place. When the admixture of a neutral fat and pancreatic juice is first of all made, the resultant liquid is alkaline, owing to the alkaline character which the pancreatic juice en- joys. In the course of a few hours, however, a de- cidedly acid reaction is found to exist, and this arises 188 INTESTINAL DIGESTION. from the decomposition which the fatty matter under- goes. The neutral fats are chemically acted upon by the pancreatin, and resolved by it into their con- stituent acid and glycerin. The liberation of the fatty acid thus accounts for the acid behavior which the emulsion, as above mentioned, in the course of time acquires. It is only with pancreatic juice of good quality that this acidification of the neutral fats is found to be brought about. The tissue of the pancreas behaves in the same manner as the secretion, but it requires to be fresh. According to Bernard, the power of acidifjdng neutral fats characterizes pancreatin from all other products of secretion, and it has been sug- gested by him as furnishing a means of recognizing the pancreas in members of the animal series where a doubtful condition exists. Although the pancreatic juice is endowed with this chemical power, yet such, it is to be observed, is not exercised under physiological circumstances. The emulsifying action is immediate, but the chemi- cal change requires time to be allowed for its produc- tion, and the emulsified fat is not long delayed in the intestine before its absorption is effected. As a con- clusive argument upon the subject, it has been found that the fatty matter reaches the chyle without pre- senting evidence of having undergone an3^ chemical alteration. The negative evidence derivable from the suppres- sion of the influence of the pancreas is confirmatory of its possessing a digestive power over fat. Dr. Bright, as far back as 1832, related cases at the THE PANCREATIC JUICE. 189 Medical and Chirurgical Society, in which he had noticed the voidance of large quantities of fatty mat- ter with the alvine evacuations in connection \vith malignant disease of the head of the pancreas and ul- ceration of the duodenum. Dr. Bright, however, stated that he did not affect to decide whence the peculiar fatty matter was derived — whether it was thrown out from the diseased parts, or whether it formed a product of defective digestion. Bernard's researches have since supplied the explanation, and it has been found that, on experimentally destroying the secret- ing power of the pancreas, which can be done by forcibly injecting oil through the duct into the tissues of the gland, fat is voided with the dejections when fatty matter is given with the food. A further function, that of acting as a supplemen- tary organ to the stomach in the digestion of azotized materials, has also been assigned to the pancreas. Purkinje and Pappenheim, in 1836, asserted that the pancreas contained a principle capable of exerting a digestive action upon the azotized elements of food. This assertion, however, did not lead to any further result, and the matter was suffered to drop until its recent revival by Corvisart, of Paris, who now stren- uously maintains that the pancreas, in addition to its other functions, acts as a supplementary organ to the stomach, and digests, after a copious meal, the nitro- genized alimentary materials that happen to have escaped being digested in that viscus. He states that the nature of the two digestions — gastric and pancreatic — is alike as far as the result is concerned, each leading to the production of albuminose. Whilst, 190 INTESTINAL DIGESTION. however, the existence of acidity forms a necessary condition for the exercise of digestive power in the case of the gastric juice, the secretion of the pancreas, he affirms, enjoys the privilege of acting equally well whatever the reaction that may exist — no matter, in other words, whether it may chance to be in an acid, a neutral, or an alkaline state. Three sets of experiments are brought forward by Corvisart in support of his affirmation. First, he says, that if the pancreas of an animal be taken when its active principle is at its maximum in quantity and quality — that is, from the fourth to the seventh hour after the commencement of digestion — and be immediately finely cut, and infused for an hour with twice its volume of water at a temperature of 20° Cent. (68° Fahr.), and the infusion be at once experimented with, it will be found to possess the power of dissolving the nitrogenized alimentary prin- ciples and converting them into albuminose; and this without any evidence of ordinary putrefaction being perceptible, if the experiment be stopped at the end of four or five hours, in which time, under exposure to a temperature of about 100° (Fahr.), the pancreatic principle will have accomplished all that it is capable of efiecting. Secondly, that the pancreatic juice obtained from the duct of the gland during life is found to be capa- ble of exerting likewise a j^owerful solvent action upon the nitrogenized alimentary principles when the proper rules are observed in conducting the ex- periment. To exhibit the digestive power in ques- tion, the operation, he says, must be performed four THE PANCREATIC JUICE. 191 hours after the ingestion of food, and the juice be experimented with that flows during the following three hours, the period at which it is charged to its maximum extent with the pancreatic principle. It must also be experimented with immediately after its collection. Pancreatic juice, according to Corvisart, dissolves fibrin more rapidly and largely than albu- men. The heat being maintained between 42° and 45° Cent. (108° and 113° Fahr.), a specimen of pan- creatic juice of ordinary energy dissolves, he says, if agitated with the aliment submitted to its action every quarter of an hour, all that it is capable of dissolving of fibrin in two or three hours at the most, and of solid albumen in four or five hours : the experiment, up to this period, being unattended with any evidence of ordinary decomposition ; whilst, subsequently, or- dinary decomposition is found to set in. Thirdly, that azotized substances introduced into the duodenum at a period when pancreatic juice is flowing into it are found to be dissolved, notwith- standing that the gastric juice and bile are shut off, by ligaturing the pylorus and bile-duct. I was formerly of opinion that in the effects pro- duced upon azotized matter by the pancreatic juice, we had to deal with changes of the character of pu- trefaction rather than true digestion. I must con- fess, however, that, although putrefaction very readily and rapidly sets in, I am now inclined to believe, upon the evidence of more recent experiments, that some amount of action may be exerted which cannot be ascribed to putrefaction. I have carefully followed the rules laid down by Corvisart ; and although in 192 INTESTINAL DIGESTION. some of my experiments the results have not been free from signs of accompanying putrefaction, yet I have observed, what I presume must be considered, digestive action without it. The pancreas of the dog, for instance, has been taken at periods varying from four and a half to seven hours after the ingestion of food, and immediately either chopped up finely or bruised in a mortar, and infused for from half an hour to an hour in from three to six ounces of water. Frosrs less have been used as the test, as in my experiments upon gastric digestion, and the temperature employed has ranged between 105° and 115° Fahr. Upon some occasions, in about four hours' time the legs, although appearing exter- nally intact, were acted upon in such a manner that the soft parts easily broke down under very slight pressure — and this without any smell of decomposi- tion being apparent. Upon other occasions, and in the same period of time, a more or less strong smell of decomposition has been present. Where the action has been allowed to continue longer, an extensive disintegration of soft parts has been observed, but the product has smelt most strongly of decomposition. The bones have not been found to suffer attack as they do with gastric juice. It is true, a strongly solvent action is exerted upon animal matter in the interior of the duodenum. With the pylorus and also the bile-duct ligatured, and the frog's legs introduced into the duodenum, I have found in a few hours' time that the soft parts have been dis- solved so as to leave the house in a perfectly clean state behind. In such an experiment it must be borne THE LIVER. 193 in mind that there is intestinal as well as pancreatic juice to act. And that the former can exert some effect, may be looked upon as shown by the result obtained in another experiment, where, a ligature being applied around the duodenum below the pan- creatic duct, and the frog's legs introduced below this, a considerable amount of digestive action was still observed to occur. The liver forms by far the largest of all the gland- ular organs of the body, and is the most universal in its presence throughout the animal series. There are few animal beings, indeed, that are possessed of a digestive cavity, where some form of biliary appa- ratus cannot be discovered. The power of secreting bile exists before any distinct organ is found to be developed for the purpose. Thus, in some of the lower animals, where nothing in the shape of a dis- tinct liver is present, cells are to be seen lodged in the walls of the digestive cavity, which, from the color of their contents, are judged to be of a biliary nature, or, in other words, to perform a bile-secreting, office. The average weight of the liver in the adult human subject is from three to four pounds. It is placed in the upper part of the abdominal cavity, and concealed under and protected by the ribs of the right side. It is uniform in appearance, smooth upon its surface, and of a dark reddish-brown color. Its upper sur- face is rounded, adapting it to the concave under sur- face of the diaphragm, with which it lies in contact. Its under surface is flattened and marked by certain fissures which map it out into portions called by anato- 13 194 INTESTINAL DIGESTION. mists its lobes. To this under surface is attacliecl the gall-bladder, a temporary receptacle for the bile. Its posterior border is rounded or obtuse, and fixed to the abdominal walls by reflexions of serous membrane passing from its upper and under surfaces. Its ante- rior border is sharp and free, and corresponds with the lower margin of the chest. A thin capsule of fibrous tissue is found to invest it, and over this is the serous layer derived from the peritoneum, which gives to the organ the shiny or glistening surface it presents. The reflexions of peritoneal membrane connecting the liver with surrounding parts serve to suspend and keep it in position, and are anatomically spoken of as ligaments. The liver is an exceedingly vascular organ, the blood that passes through it being derived from two sources, an arterial and a venous. The arterial blood must be looked upon as specially intended for con- tributing to the maintenance or nutrition of the or- gan ; the venous blood, on the other hand, which con- sists of the blood which is being returned from the stomach, intestines, pancreas, and spleen, is designed for administering to its functional operations. The first-named blood reaches the liver through the he- patic artery, the latter through the portal vein. The blood from both these sources traverses the capillaries of the organ, and reaching the hepatic vein, is thereby conducted into the inferior cava, and thence to the right side of the heart. On looking closely into the texture of the liver, it is seen to be made up of a multitude of small, closely packed, tolerably equal-sized masses, which THE LIVER. 195 constitute the hepatic lobules. These lobules form an exact repetition the one of another, and each may be looked upon as representing, as it were, an ele- mentary liver, the entire organ being simply, in fact, composed of a collection of these primary compo- nents. The lobule consists of bloodvessels lying in close relation with cells — the hepatic cells which form the secreting element. Blood reaches the circumference of the lobule through the branches of the portal vein. Capillary vessels are derived from these, which con- verge to the lobular centre, and there terminate in a radicle of the hepatic vein. The blood also which traverses the hepatic artery finds its way into the converging capillary plexus of the lobule, and so reaches the hepatic vein, the vessel by which it is re- turned from the liver into the general circulation. The substance of the lobule is in great part com- posed of the hepatic cells, which are therefore exceed- ingly numerous. They lie closely interwoven with the capillary bloodvessels ; and thus the blood and the secreting element of the liver are brought into the closest relation with each other. The cells con- sist of nucleated particles, varying in size from the 1000th to the 2000th of an inch in diameter. In form they are more or less spheroidal — or often poly- hedral from mutual compression. Fat-globules and pigment-granules are usually to be seen in them as well as the nucleus. The manner in which the secreting cells of the lobules are connected with the hepatic duct has formed a much-debated point amongst anatomists. Kiernan 196 INTESTINAL DIGESTION. was of opinion that the hepatic duct commenced as a plexus in the lobule, which he styled the lobular or secreting biliary plexus. He had never succeeded in fully displaying this plexus ; but, from the ramifi- cations of the ducts between the lobules, he had seen branches passing into them and forming a plexus at their circumference. Dr. Beale asserts that he has succeeded in demonstrating the existence of very delicate tubular processes of basement membrane ex- tending into the lobules from the hepatic ducts, and inclosing the hepatic cells. The arrangement which Kiernan conjectured to exist Dr. Beale believes he has succeeded, by injection and otherwise, in display- ing. A lobule, he says, is composed of a network of capillary bloodvessels, intertwined in the closest manner possible with a network of exceedingly deli- cate tubules which form extensions of the hepatic duct and inclose the hepatic cells. This he calls the cell-containing network of the lobule, and from the relation it holds to the bloodvessels, the secreting ele- ment of the liver is brought into the closest intimacy with its vascular supply. Usually, Dr. Beale says, there is room for only one row of cells in the tubules, though in some portions of the network two and three rows have been found. The cells lie unattached in the tubules. The minute branches of the hepatic duct emerging from the lobules unite with each other, and the pro- cess of coalescence is continued until ultimately the single duct that escapes from the under surfixce of the liver is formed. This — the hepatic duct, after coursino; for a short distance downwards towards the THE BILE. 197 duodenum, is joined by a canal — the cystic duct, which connects it with the gall-bhidder. Below this point, the duct which convej^s to the duodenum both the bile that has passed into the gall-bladder and that which is descending direct from the liver is known by th^ name o^ ductus communis clioledoclius. Before its termination the ductus communis choledochus ar- rives in contiguity with the pancreatic duct. The two then run side by side, and ultimately open into the duodenum together, upon the summit of a papilla about three or four inches below the pylorus. The gall-bladder constitutes a diverticulum or re- ceptacle connected with the hepatic duct, intended for the temporary retention of bile, when its flow into the intestine is not required. It forms a pear-shaped bag, capable of holding rather more than an ounce. Con- siderable diversity, it is to be mentioned, is found to exist as regards its presence amongst the different members of the animal kingdom. It is not present in any of the invertebrata. It is usually met with in fishes, but in many of the class it is absent. In all reptiles it exists. In some birds it is present; in others, absent. In mammals, also, it is not invari- ably present ; the horse, elephant, and stag, for exam- ple, may be referred to as forming instances in point. The secretion of the liver, or bile, forms a clear liquid, having a more or less viscid consistence, and a color that ranges under different circumstances and in different animals through shades of green, brown, and yellow. In the human subject it is of a green or yellowish-green color in its concentrated form, and becomes of a bright yellow on being diluted. Its 198 INTESTINAL DIGESTION. taste is bitter, with a slight after-taste of sweetness. When fresh, it has very little odor ; but what there is authorities describe as somewhat resembling in character the odor of musk. Its usual sp. gr. may be said to vary between 1020 and 1030. Its ordi- nary reaction Lehmann pronounces to be weakly alkaline, but says that it is often found perfectly neutral, and rarely, and then only in disease, acid. When poured into water it sinks to the bottom, but on agitation readily mixes, forming a liquid that froths like a solution of soap. Indeed, chemically speaking, it may be regarded as constituting a kind of soap, and thus is accounted for the estimation hi which ox-gall is popularly held as a detergent. It is generally de- scribed as being very prone to undergo putrefaction on keeping. Such is the case with weak or poor bile; but rich bile, I have repeatedly found, simply dries up on exposure to the atmosphere, without show- ing any signs of undergoing decomposition. The chief principles of bile may be said to consti- tute its resinous and coloring ingredients. Besides these, however, it always contains : a small amount of cholesterin (a crystallizable, non-saponifiable fat) ; some neutral fatty matter; combinations of the fatty acids with alkalies ; mucus derived from the biliary passages; various saline materials; and water. The proportion of solid matter amounts to about ten per cent. Beyond some epithelial particles derived from the mucous lining belonging to the canals through which the bile has passed, there is nothing under natural circumstances brought into view by means of the microscope. THE BILE. 199 Much difference of opinion has prevailed regarding the chemical nature of the resinous matter, forming: one of the main ingredients of the bile. A variety of substances, now known to constitute only products of its decomposition, were formerly enumerated as if original constituents, and thus a most complex char- acter w^as given to the composition that bile was represented to possess. Berzelius spoke of the resin- ous matter as a neutral or indifferent organic sub- stance, and called it hilm. This bilin of Berzelius, however, according to the more recent researches of Liebig, Strecker, and Lehmann, appears to consist of two peculiar resinoid acids combined with soda, so as to form a kind of soap. By Lehmann these have been named the glycocJioUc and taurocliolic acids. He describes them as constituting what he calls conju- gated acids; that is, bodies in which an acid is united with a basic substance which gives to it the posses- sion of new properties, without, however, altering its saturating power. In the case of both the bodies under consideration, cholic acid it is which forms the acid principle; the basic substance, or adjunct with which it is copulated, being glyciii on the one hand and tauriri on the other. Cholic acid is a non-nitrogenized body, the formula for which is C48H39O9, HO. It approaches the fatty acids in character, and yields the same products of de- composition on distillation with nitric acid as the oleic acid. Whether in a free state or copulated with an adjunct, as it exists in bile, it may always be recog- nized by its behavior with sulphuric acid and sugar. This reaction constitutes what is called Pettenkofer's 200 INTESTINAL DIGESTION. test, and the following is the way in which it is ap- plied. The liquid to be examined is treated in a test- tube with a drop or two of a dilute solution of cane sugar ; and then, concentrated sulphuric acid is slowly poured in, taking care to avoid too great an elevation of temperature being produced. A cherrjM^ed, fol- lowed by a beautiful purple color, is produced when cholic acid is present. Glycin, with which cholic acid is conjugated in glycocholic acid, is a body composed of carbon, hy- drogen, oxygen, and nitrogen. It is the same as gly- cocoll, or sugar of gelatin, which has long been known as constituting one of the products of the decompo- sition of gelatin by mineral acids and alkalies. Gly- cocholic acid in most animals forms the chief or- ganic constituent of the bile. Being but very spar- ingly soluble in water, it is thrown dowai from its al- kaline solutions by the addition of an acid. It is glycocholic acid which constitutes the dense precipi- tate produced when rabbit's bile is treated with an acid. Taurin, in addition to the four elements met with in glycin, contains sulphur. Taurocholic acid, which results from the union of taurin with cholic acid, is more soluble in water than the glycocholic acid. It also has the power of dissolving fats, fatty acids, and cholesterin in large quantities, and its presence is the cause of glycocholic acid not being precipitable from fresh ox-bile and the bile of many other animals upon the addition of an acid. The coloring matter of bile has not yet been sej^a- rately obtained in a state of purity. Two kinds of THE BILE. 201 coloring matter appear to exist — a brown and a green. The green is most abundant in the bile of the vege- table feeder. It forms the biliverdin of Berzelius, and was thought by this chemist to be identical with chlorophjdl, the green coloring matter of plants. Professor Stokes, however, has recently recognized differences in the optical properties of the two which he considers sufficient to show that they are distinct from each other. In human bile the brown variety, which has been named cholepyrrhin, preponderates. It is this which produces the well-known reaction, or characteristic play of colors with nitric acid. The biliary concretions which sometimes form in the gall-bladder, and thence may give rise to so much subsequent distress, almost invariably consist of cho- lesterin. Sometimes, however, it happens that they are composed of inspissated bile. But little, as yet, unfortunately, is known about the circumstances which lead to the formation of these concretions, and therefore our treatment rests upon a most imperfect basis. They are more common in women than in men, and are seldom met with in persons under thirty years of age. Sedentary habits seem to favor their production. The most discordant estimates have been given concerning the quantity of bile secreted in man. Blondlot calculated that it amounted to about six or seven ounces in the twenty-four hours, whilst Bidder and Schmidt have more recently put it down at eight or nine times this quantity, or about fifty-four ounces. The estimates given have been drawn from the amount of bile discharged through biliary fistulaB established 202 INTESTINAL DIGESTION. in the lower animals. Through the same means it has been ascertained that the flow of bile is continu- ous, but presents fluctuations. Its minimum flow is at a period of fasting. Shortly after the ingestion of food the flow begins to augment, and continues in- creasing until its maximum point is reached, which is not till after the completion of digestion. Bile must be regarded as having several purposes to fulfil. There are three points of view under w^iich it may be examined, viz. : 1. As an excretion. 2. As a secretion containing elements for reabsorp- tion. 3. As a secretion afibrding assistance in the digest- ive process. It is its coloring ingredient that renders bile in part an excretion. That this portion is simply des- tined for elimination from the system, is rendered evident by various considerations. In the first place, it accumulates in the intestine, forming part of the meconium during intra-uterine life, and is discharged from the system shortly after birth. It further forms throughout life a constituent of the alvine evacua- tions. The color of the dejections, indeed, is due to the coloring matter of the bile ; hence, when bile is from any cause prevented from flowing into the in- testine, the motions present a more or less colorless appearance. Again, w^ien the escape of bile through its natural channel is obstructed, its coloring matter accumulates in the system, occasioning jaundice, and is then found, like other products of the system in- THE BILE. 203 tended for excretion, to be vicariously discharged through other channels. As the urine is characterized by its richness in ni- trogen, so is the bile by its richness in carbon ; and Liebig long since broached the idea, that a great part of the bile was reabsorbed from the intestine, and subsequently utilized in the system by contributing towards heat-production. The point at which the bile is discharged, necessitating, as it does, its trav- ersing the whole length of the intestine before it can be expelled, affords prima facie grounds for conclud- ing that it has something to do besides playing the part of a pure excretion. Now, Bidder and Schmidt's experiments have shown that a reabsorption of a portion must actually occur, it having been found that the whole solid residue of the intestinal evacua- tions of a dog subsisting upon a flesh diet scarcely amounted, during a given period, to what would be contained in the bile that flowed from the liver. It is, therefore, evident that a large portion of the se- cretion must have been reabsorbed during its passage along the intestinal canal, and it is its resinoid por- tion which thus disappears. But the bile must further be looked upon as a secretion designed for affording a share of assistance in the digestive process, and as such it will now be spoken of. In the first place, then, the alkali it contains con- tributes to destroy the acidity of the gastric juice after this has fulfilled its purpose, and its presence is no longer needed. It is easy to show upon the rab- bit, that as the acid chyme reaches the intestine and 204 INTESTINAL DIGESTION. comes in contact with the bile a chemical reaction of these fluids upon each other takes place, which is attended with the displacement and precipitation of the resinoid acid principle from the bile. There is nothing to indicate that, the bile exerts any digestive influence upon either the nitrogenized or amylaceous elements of the food. Upon some fats, however, it is ca^pable of acting. The neutral fats escape, but the acid fats are emulsified by it. Now, it happens to be the neutral fats that we principally consume with our food ; but Dr. Marcet says that these neutral fats are in part acidified in the stomach, and so rendered apt for yielding to the emulsifying influence of the bile. The pancreas, however, seems fully equal to the performance of all that is wanted in connection with the digestion of both the neutral and acid fats. The co-operation of the bile, which, at the most, enjoys only a limited action, as already mentioned, upon fats, is, therefore, not absolutely needed. The bile also serves as a stimulus to excite the glandular follicles and muscular fibres of the intes- tine to proper action : hence, the constipation that is so commonly encountered in. cases of jaundice, where its flow into the intestine is obstructed ; the diarrhoea that attends its too copious secretion; and the purga- tive effect obtained by the administration of ox-gall. Although contributing to the purposes named in connection with the process of digestion, yet experi- ment shows that its presence in the intestine is not absolutely indispensable. When the bile-duct of an animal is simply occluded, death follows as an in- EFFECTS PRODUCED. 205 evitable consequence, from the retention of bile in the system. If, however, with the occlusion of the duct, an artificial means of escape be provided for the bile, recovery from the operation may take place, and life continue without any serious evidence of distur- bance. At first great emaciation follows the opera- tion, but afterwards restoration to a fairly healthy condition has been observed. A more abundant allowance of food, however, has been found necessary than under ordinary circumstances, in order appar- ently to compensate for the loss of a secretion which is in part designed for reabsorption. The physiological action of the various secretions poured into the intestinal tract having been sepa- rately examined, it now remains for the phenomena of intestinal digestion to be spoken of in a connected manner. Chyme, as the semifluid material is called, which passes from the stomach into the intestine, contains albuminose, or the product of gastric digestion; the nitrogenized digestible matters that happen to escape through the pylorus before being completely digested; nearly all the starchy matter consumed, a very insig- nificant portion only having been as yet transformed into sugar and absorbed; all the fatty matter that has been ingested, this having been liquefied by the heat of the stomach, and become divided into glob- ules, but not emulsified ; and the indigestible or in- soluble parts of the food. Reaching the intestine, the chyme becomes pro- gressively incorporated with the several secretions poured into the canal, and by the agency of these the 206 INTESTINAL DIGESTION. following changes are effected : The starch that is present is gradually metamorphosed into sugar, which is absorbed by the bloodvessels, and carried to the liver as fast as it is formed ; the fatty matter is emul- sified, and so fitted for absorption by the villi from which it is subsequently poured into the lacteals; and, lastly, the nitrogenized alimentary principles that have escaped digestion in the stomach continue to be acted upon and to be dissolved. To sum up : the intestine, it may be said, forms the seat of diges- tion of the non-nitrogenized alimentary principles — starch and fat ; and further discharges the supplemen- tary office, as regards the stomach, of digesting the non-nitrogenized aliment that happens to escape solu- tion in that viscus. The fluidity of the chyme "is at first increased by the secretions with which it is brought in contact in the upper part of the intestine, but as its onward flow takes place it becomes diminished by the activity with which the process of absorption is carried on. In the large intestine the removal of fluid by absorption preponderates over its exudation by secretion to a sufficient extent to lead to the solid consistency which the excrementitious residue is found to naturally ac- quire before its expulsion from the system. The reaction of chyme on its entrance into the in- testine is always to a marked extent acid, owing to the acid nature of the gastric juice that it contains. The secretions encountered in the duodenum have the effect of materially diminishing the acidity that is thus communicated by the stomach; and, the in- testinal juice exerting a similar action, by the time THE INTESTINAL CONTENTS. 207 the lower part of the ileum is reached, the intestinal matter may be found to present a neutral or even an alkaline reaction. In the herbivora the contents of the alimentary canal again acquire a strongly acid reaction in the csecum, and it has been suggested that a kind of second process of gastric digestion is here performed. The acidity, however, it is to be remarked, is due to the development of acid through changes occurring in the contents, and not to the secretion that is poured out; the secretion of the caecum, in fact, being alka- line, like that of the other portions of the intestinal tract. It may be further remarked, that from the mucous membrane of the ceecum no infusion possess- ing digestive properties when acidified is to be pro- cured, like what can be obtained from the mucous membrane of the stomach. The color of the contents of the stomach depends upon the nature of the food. In the duodenum the chyme is brought into contact with a highly colored fluid — the bile ; but the influence of this on the ali- mentary matter is at first obscured by the opaque whiteness of the emulsified fatty matter, and the pre- cipitation of resinoid matter which takes place from the bile itself Thus it is that in the upper part of the small intestine a cream-like appearance is pre- sented by the contents. In the lower part, however, on account of the extraction that has been eflected by absorption, a more or less deep yellow color is observable, which is shown to be dependent on the coloring matter of the bile, by the behavior that is noticed on the nitric acid test being employed. In 208 INTESTINAL DIGESTION. the large intestine a transformation of tlie yellow color into brown is brought about, and now nitric acids fails to develop the reaction of bile. When bile is prevented from reaching the intestine, as in cases of jaundice, it is well known that the dejections are voided in an almost colorless condition. This affords strong evidence that the color of the faeces is due to the coloring matter of the bile. A special odor belongs to the dejections, which varies in different animals. The odorous principle, agreeing as it does with the odor that is specific to the body of the animal, and that appears in various degrees of intensity in all its different excretions, is doubtless derived from the blood. It has been sug- gested that it is from the bile that the fecal matters acquire it, but there is greater probability that it is from the intestinal glands that it comes. What is to be noticed in the fowl has strongly convinced me per- sonally that the latter is its true source. A pair of long, narrow, csecal appendages, for instance, are met with in connection with the intestine in the fowl, which are pointed to as marking the separation be- tween the small and large divisions. They form glandular processes, and are not transversed by fecal matter. Now, on laying these coscal appendages open, the characteristic odor of the faeces of the animal is found to be evolved in a very concentrated form. Various gases are encountered in the alimentary canal. Amongst these, oxj^gen, nitrogen, hydrogen, carbonic acid, and carburetted and sulphuretted hy- drogen, have been recognized. The first two are doubtless principally, if not entirely, derived from the THE INTESTINAL CONTENTS. 209 air, which is entangled amongst, and, thus constantly being swallowed with the food. The others must arise from the changes that occur in the food or se- cretions, or else form products of elimination by secre- tory action direct from the blood. That such an elimination of gas can take place from the blood is evidenced by what is observed in the case of the swim- ming-bladder of the fish ; and also by the fact, that an odorous gas, which has been received into the sys- tem through the lungs, is afterwards found, from the odor presented by the dejections and flatus, to have unmistakably reached the interior of the intestine. In the experiments that have been made on the in- testine with reference to this matter, it has been found that an empty coil inclosed between a couple of liga- tures has become subsequently distended with gas. It must not be concluded, however, that the gas which has accumulated under these circumstances has neces- sarily formed a product of secretion, for it might with equal probability have been derived from the occur- rence of decomposition within, it being impossible to exclude all source for the generation of gas in this way. The period of time taken for the transit of matter through the intestinal canal varies considerably in different individuals, and under different circum- stances. Under the existence of diarrhoea, the whole length of the intestine may be traversed in a couple of hours, whilst on the other hand, weeks, or even months, it may be said, have been occupied in cases where mechanical obstruction has existed. Probably about twelve hours is the time ordinarily taken for 14 210 INTESTINAL DIGESTION. transit throiigli tlie small intestine to be effected, and about thirty-six liours for the sojourn of matter in the large. The accumulation of fecal matter at the lower ex- tremity of the alimentary canal occasions an impres- sion which creates a desire for its expulsion from the system. Under the influence of habit, the desire thus created may be made to recur with the utmost regu- larity. Nothing, indeed, can be more complete than the regularity with which the alimentary canal can be brought to discharge its defecative function, and nothing is more necessary for health than the culti- vation of a regular habit in this respect. Where it occurs that the call of nature is frequently neglected to be responded to, through the accumulation that is thereby allowed to ensue, the mucous surface of the rectum loses its natural impressionability and the muscular fibres their tone ; the distension becomes greater and greater, and the power of expulsion cor- respondingly less, until it arrives that the artificial aid of a purgative or an enema requires to be had re- course to in order to procure an evacuaticm. Thus, by a simple want of attention, in the first instance, to the dictates of nature a host of miseries may be occasioned : for, dejection of sj)irits, derangement of the stomach and liver, hemorrhoids, and a multipli- city of other ills, follow as attendants upon consti- pated bowels. It is by the presence of foreign matter in the vi- cinity of the outlet of the canal, that the act of defe- cation is excited, and thus it arises that the intro- duction of a bread suppository into the rectum is often DEFECATION. 211 sufficient in the child to produce an action of the bowels. Defecation is essentially a reflex-spinal act. The will, however^ can exercise a controlling influ- ence over its performance. A little voluntary strain- ing brings the egesta w^ithin the sphere of distribu- tion of the incident, or excitor nerves connected with the process, and a definite reflex movement is there- suit. After the experimental division of the spinal cord it is found that the application of a stimulus to the lower end of the rectum excites a series of rhyth- mic movements wdiich result in the complete per- formance of defecation, when anything exists in the neighborhood of the outlet to be voided. Under such circumstances it is evident that neither the will nor sensation can have had anything to do with the phe- nomenon. Fortunately for our comfort, however, it is found that, when the wdll is free to operate, a re- straining influence can be exercised by it over the performance of the process. Still it may arrive, where a high state of morbid irritability happens to exist, that the influence of the stimulus tending to the production of reflex action may be stronger than the controlling power of the will; and thus, in spite of all the voluntary effort that can be brought to bear to the contrary — in spite of all the voluntary power that can be thrown upon the sphincter, towards keep- ing it in a state of contraction — the act of expulsion is found to result. The matter ejected* from the alimentary tract by defecation consists of (1) the materials that are found to be refractory to the solvent influence of the vari- ous secretions poured out for digestion; (2) whatever 212 INTESTINAL DIGESTION. of a digestible nature may chance to escape under- going digestion and absorption (the microscope, for instance, may display starch-granules and other vege- table elements, muscular fibres, and other elements of animal structures and fatty matter) ; and (3) vari- ous products, such as epithelium, mucus, the color- ing matter of bile, etc., derived from the digestive organs themselves. The meconium or excrementi- tious matter first expelled from the alimentary canal after birth, entirely consists of products derived from the digestive tract and its glands. Dr. Marcet has separated a special product of ex- cretion from the alvine dejections, to which he has given the name of excretin. This substance, which he has obtained in a crystalline form, closely resembles, he says, cholesterin in its properties; and further, he thinks, has some physiological connection with cholesterin, inasmuch as he has found the excreta of very young children to contain cholesterin and no excretin, whilst exactly the reverse was held good in the case of young people and adults. COLIC— ENTERALGIA. When a muscle is thrown into a state of unnatural or spasmodic contraction, pain constituting cramp is the result. The muscular fibres of the intestine are not exempt from liability to be thrown into this ir- regular mode of action or spasm ; and what is called colic, bellyache, or the gripes, forms the complaint resulting therefrom. A variety of causes constitute excitants of this condition, and upon the nature of the cause will depend the degree of import belonging to the affection, which may range from one of a trivial and passing nature to one of the utmost gravity and danger. It should be always borne in mind that colic, if not overcome, may, by the deranged action arising from the obstruction produced, pass into enteritis, or acute inflammation of the bowel. Through irregu- larity of muscular action, also, one portion of bowel may become accidentally inserted into another, form- ing what is known as intussusception — a condition more particularly encountered in infancy and child- hood. The causes of colic, or the conditions giving rise to spasmodic contractions of the intestinal muscular coat, may be grouped into : sources of irritation ex- isting within the canal ; abnormal states in respect 214 COLIC. of structure and position of the intestinal tube ; con- tamination of the system with lead ; and certain gen- eral and remote affections implicating in a secondary manner the muscular fibres of the intestine. The sources of irritation within the canal that may produce colic comprise such as fiatus, worms, irritating ingesta of any kind — whether of the nature of food or otherwise, morbid secretions, intestinal concretions, and unduly retained excrementitious matter. Idio- syncrasies exist, and an article that is food for one man may be poison to another — setting up violent derange- ment accompanied with colic. As regards colic attributable to the condition of the intestine itself, anything which causes an occlusion of the canal or impedes the passage of its contents will lead to irregular action of its muscular fibres above the seat of obstruction, and thus occasion colic. Morbid structural conditions hading to constriction, hernia, and internal strangulation from whatever cause arising, act in this way. An inflamed, ul- cerated, or any diseased state, which renders the mu- cous surface morbidly irritable, may be the source of colic, through the increased readiness with which un- due muscular contraction is excited. With respect to colic arising from general and re- mote causes, contamination of the system with lead is a well-known source of one of the most severe forms of the affection that is met with. As occasional ex- citing causes falling under this head must also be enumerated strong passions and emotions in persons of a nervous or irritable temperament, exposure to cold, dentition, and uterine derangement. The hys- ENTERALGIA. 215 terical and gouty dispositions form habits of body which predispose to the occurrence of colic. The treatment of colic must be regulated by what is found or believed to be its exciting cause ; but pur- gatives, anodynes, narcotics, and antisj)asniodics, ad- ministered by the mouth or used as enemata, are the medicinal agents that will have to be selected from, according to tlie circumstances of the case. Friction with stimulating liniments, hot fomentations — medi- cated and simple, and the mustard poultice or tur- pentine stupe, applied to the abdomen, often assist materially the other measures adopted. The warm bath has also a powerful effect in overcoming spasm, and should, therefore, in obstinate cases, not be left untried. When a free action of the bowels can be obtained, relief is generally afforded. The particular treatment required for colic arising from structural disease, mechanical displacement, and obstruction of the intestine, and also from lead poi- soning, would be beyond the purport of this work to refer to. It is probable that, as with the stomach, a morbid sensitiveness of the mucous membrane of the intes- tine may sometimes exist and constitute, instead of colic, the cause of pain referable to this portion of the alimentary canal. Enteralgia and enterodynia are names given to this condition, about which but little of a definite nature can be said. Abercrombie speaks of four forms of gastralgia, and refers one of them to a painful condition of the first part of the small in- testine. Pain, for example, beginning from two to four hours after a meal, and continuing for some 216 ENTERALGIA. hours — a form of complaint that is not unfrequently encountered — Dr. Abercrombie thinks, is probably seated in the duodenum and connected with inflam- matory action or morbid sensibility of its mucous membrane. This form of affection, continues Aber- crombie, is often accompanied Avith pain and tender- ness on pressure in the right hypochondrium, and on that account is apt to be mistaken for disease of the liver. As regards treatment, what has been said under the head of gastrodynia may be taken as applying also to enteraloia. INTESTINAL FLATULENCE.— TYMPANITES. The inordinate accumulation of gas in tlie stomach has already been treated of. As the result of de- ranged intestinal action, gas is also apt to accumulate to an unnatural extent in the intestine. It may arise from exhalation from the mucous surface (at least there are good grounds for believing so) ; or form a product derived from the occurrence of changes of de- composition amongst the contents of the canal. The presence of flatus in the intestine may give rise to irregular contraction of the muscular coat ac- companied with pain constituting colic. The move- ment of the flatus is often accompanied with rumbling noises in the abdomen, which are termed "borbo- rygmi." In some cases the fibres of the colon contract around an accumulation of gas, and make it appear that a circumscribed tumor exists. This can be moved about like an ordinary tumor, and in other respects may feel so like one as to render it difficult to convince the patient that no actual morbid growth exists. The patient will admit that sometimes it can be felt, at other times not ; and not unfrequently that it is sometimes to be foinid on one side and sometimes on the other side of the abdomen. Its phantom na- ture is shown by the sudden disappearance that may 218 TYMPANITIS. be generally induced by a little manipulation. Per- cussion clearl}' discloses in reality when it is a flatu- lent accumulation that lias to be dealt with. When the distension of the intestine with gas is general, a swollen and resonant or drum-like state of the alxlomen is produced, which constitutes what is known as tympanitis. In various adynamic forms of disease there seems to be such a loss of tone in the muscular tissue of the alimentary canal that no power exists to expel the gas that accumulates, and thus the tympanitic distension of the abdomen may become such as to form, not only the most distressing, but even the most alarming feature of the case. In ordinary flatulence of the intestine the treatment should be directed towards correcting the state of the secretions that may be out of order, and improving the digestive powers and tone of the alimentary canal. The diet should be regulated: all indigesti- ble articles of food being avoided. As in flatulence of the stomach — and it is only anatomically that the two affections are separated — carminatives and anti- spasmodics are often needed for temporarily reliev- ing distress. For the treatment of tympanites — carminatives, stimulants, and antispasmodics, administered by the mouth ; enemata of rue, assafoetida, and turpentine; friction of the abdomen with stimulating liniments ; and stimulating epithems applied to the abdomen, form the medicinal resources at the disposal of the practitioner. In extreme distension it has been rec- ommended to draw off the gas through a flexible tube introduced into the colon. The process has TYMPANITIS. 219 been tried, and cases are reported in which it has been attended with success. By its means it is stated that Dr. Osborne, of Dublin, upon one occasion re- duced a tympanitic abdomen in about an hour to nearly its natural size. DIARRHOEA. By tlie peristaltic action of the intestinal muscular fibres the alimentary matters are propelled through the small intestine at that rate of speed, under natu- ral circumstances, which allows intestinal digestion to be completely carried out, and absorption of the products, both of gastric and intestinal digestion, to be thoroughly effected. The unabsorbed residue is transmitted from the small into the large intestine in a semifluid state. Here the transit is slower, and absorption of fluid is carried on so as to give a con- dition of solidity to the egesta before their discharge from the body takes place. Now, if from any cause the alimentary matters are unnaturally hurried along the intestinal canal ; or the elimination of fluid from the intestinal glands is in excess ; or its removal by absorption in default, the evacuations will fail to possess a natural consistence — in other words, will be loose and watery. As an almost invariable con- sequence of such a state, a more frequent call than is natural for the performance of defecation is excited, and thus diarrhoea, which is understood to signify the occurrence of frequent and loose alvine evacua- tions, is said to be established. The manifestation of deranged action of the in- DIARRHCEA. 221 testine now under consideration forms one of the commonest complaints that the medical practitioner is called upon to treat. It may either occur in the course of — as a symptom of, another disorder, as, for example, typhoid fever, phthisis, &c.; or present itself as a primary and independent affection. Under all circumstances, it arises from an influence morbidly affecting either the muscular or mucous coat, sepa- rately or together, of the intestine. Diarrhoea may be suddenly induced in a suscepti- ble person by a mental impression, particularly, for instance, by the operation of a depressing emotion, such as grief or fear. Rumbling and gurgling noises are heard in the abdomen ; and soon, loose alvine evacuations are passed, which must be referred to an increased peristaltic action of the muscular coat as their cause. Far more frequently it is the mucous coat that is primarily concerned in the production of diarrhoea. A variety of causes contribute to establish a state of irritation or inflammation of this coat, by which diarrhoea is set up. Its secreting and absorbing functions become deranged in action, and excited peristaltic movements of the muscular coat are sec- ondarilv induced. It has just been stated that a variety of causes con- cur in morbidly affecting the mucous coat, so as to occasion diarrhoea. In the diarrhoea of typhoid fe- ver, and in that which occurs in the course of some other allied disorders, it is through a septic poison developed in the system that the morbid condition is brought about. The foul effluvia emanating from 222 DIARRHOEA. drains and cesspools, and atmospheric miasmata of other kinds, will sometimes rapidl}^ give rise to diar- rhoea. Here the effect must be attributed to the ab- sorption of an agent through the lungs that has the property of acting as an irritant upon the intestine. By the flatus that is expelled under such circum- stances, presenting more or less the odor of the atmos- phere that has been breathed, it may be assumed that it is in the fulfilment of an eliminative office that the intestinal mucous membrane becomes affected. The most common cause of diarrhoea is the presence of something in the intestine which acts as a topical irritant to its mucous coat. It may be that an actual irritant poison has been swallowed; or, simply that something of an irritating nature has been ingested with the food — that something, in other words, has been taken, which, as the phrase goes, " has disa- greed ; " or, it may be, that a discharge of vitiated bile forms the source of the disorder. Exposure to damp and cold may affect the mucous membrane of the intestine, as it does so frequently that of the re- spiratory passages, and thus again may diarrhoea be set up. Lastly, diarrhoea arising from a morbid con- dition of the mucous membrane may be produced by a constitutional or internal cause. In some cases of diarrlioea — diarrhoea lienterica — the ingesta pass through the alimentary canal almost unchanged. This form of diarrhoea mostly occurs amongst children, and is frequently observed as a concomitant of tabes mesenterica. It is evident that the digestive as well as the absorbing powers are se- riously at fault. The appetite is usually voracious, DIARRHCEA. 223 «and, from the food failing to reach its natural desti- nation, extreme emaciation and debility become in the course of time established. The treatment of diarrhoea must be shaped accord- ing to the nature of the cause that has determined it. In that dependent on a mental influence, if it should not subside by itself, a few doses of a sedative will be usually found to effect all that is required. In the diarrhoea which is consequent upon the in- gestion of an offending article of food, the first object is to get rid of the noxious agent from the primce vice ; the next, to control the effects resulting from its irri- tating action upon the mucous lining. The vomiting and purging that are occasioned by the presence of irritant matter in the stomach and intestine must be looked upon as salutary efforts of nature designed to expel an ofi'ending agent from the system : hence such phenomena ought not at first to be checked. But, it may afterwards arrive, that the morbid action is kept up by the state of the mucous membrane that has been inducted ; and now, soothing or controlling meas- ures are required. In this form of diarrhoea, therefore, the diarrhoea cra2ndosa of Cullen, which is accompanied with nausea, and may be, with vomiting, a white and furred tongue, foul breath, fetid evacuations, flatulence, griping pains in the bowels, and an absence of fever, the appropri- ate remedy at the onset is something to assist nature in expelling the source of irritation from the alimen- tary canal. If the case be seen at the beginning a purgative, with which it is desirable to conjoin an anodyne, should be given : as, for example, from two 224 DIARRHCEA. to five grains of calomel with half a grain of opium ; or fifteen to twenty grains of rhubarb with half a grain of opium ; or an ounce of castor oil with ten drops of laudanum. At a later stage something to exert a re- straining influence should be administered, and what is usually given consists of chalk mixture, with an opiate, an aromatic, and a vegetable astringent. In the diarrhoea which forms so prevalent a com- plaint towards the end of summer and the beginning of autumn ; and which seems to depend as much, or more, on atmospheric conditions as on the ingesta ; the astringent combination that has just been referred to may be commenced with • immediately. Another treatment for this kind of diarrhoea, and one which sometimes proves very successful and a short time since had great popularity, consists of the dilute sul- phuric acid, which may be given in doses of from twenty to thirty drops with a little syrup in an ounce of water. Rest in the recumbent position, hot fomentations, or even a turpentine stupe to the abdomen, form im- portant adjuvants in a case of severity. It may be, notwithstanding the remedies admin- istered, that the diarrhoea continues, and that the flux is so profuse as to call for the use of a mineral astringent. The acetate of lead is found to be the most efficient for the purpose. It may be given in two-grain doses, with half a grain of opium, every three, four, or six hours, according as it is seen the circumstances of the case require. For the diarrhoea of phthisis, and for administra- tion in many other cases where diarrhoea is met with DIARRHCEA. 225 in its more chronic form, I am induced to speak in terms of high commendation of a mixture — the Mis- tura Haematoxjli composita of the Guy's Pharmaco- poeia, which is thus composed : R. Misturae Cretse, f^xij ; Extract! Hsematoxyli, ^ij ; Villi Ipecacuanhae, f^ij ; Villi Opii, f^j. Misce, et detur fluidiiiic. j, bis, ter, ssepiusve quotidie. For checking the loose stools that occur in typhoid fever and some other morbid states nothing is found to act more efficaciously than an o]Diate clyster or suppository. Thirty minims, for instance, of lauda- num in about four ounces of barley-water or decoc- tion of starch may be thrown into the rectum ; or ten grains of the soap and opium pill be used as a sup- pository, as often as occasion may happen to require. In the diarrhoea of infants, arising either from im- j)roper or unwdiolesome food, or from the irritation of teething (a class of cases which is so frequently en- countered by the physician in the out-patient practice of an hospital) , I am in the habit of giving, and with the most satisfactory result, a little ipecacuanha with a bitter and a saline. My prescription consists of a few minims of the Yinum Ipecacuanha?, twenty min- ims or so of the tincture of calumba, and one to two or three drachms of the Mistura Salina of the Guy's Pharmacopoeia, which is made hy saturating a solu- tion of carbonate of potash, containing twenty grains of the carbonate to each lluidounce of water, with lemon-juice. Conjoined with this, a couple of grains 15 226 DIARRIICEA. of gray powder are sometimes given as an alterative every morning ; or sometimes, a powder consisting of a quarter or lialf a grain of calomel, two grains of the dried carbonate of soda, and five grains of the aromatic powder of chalk. In the form of diarrhoea now being spoken of there exists a state of irritation of the whole gastro-intes- tinal tract. The appetite is ca]3ricious — sometimes ravenous, at other times absent. The tongue is white in the centre, red at the tip and edges. The breath has a sour smell. Occasionally there is vomiting. The abdomen is swollen and tympanitic, and more or less tender. The motions are unnatural in color — generally green, like spinach — and exceedingly of- fensive. The child is peevish and fretful, and its sleep is disturbed. Emaciation, particularly in the limbs, rapidly proceeds ; and where the morbid con- dition is allowed to run on, a state of marasmus, with mesenteric disease, becomes established. There is frequently with the train of symptoms referred to more or less accompanying bronchial complication, indicated by cough and rattling or wheezing at the chest. Here, a few minims of the syrup of poppies added to the mixture above mentioned will prove beneficial. ' The diet in diarrhoea should consist principally, if not exclusively, of farinaceous articles of food — such as rice, sago, tapioca, arrowroot, corn-flour, and bread — with milk, and chicken or mutton broths. Beef- tea, it should be remembered, will sometimes by itself produce in a weak person a looseness of the bowels. Green vegetables and fruit are to be proscribed. DIARRH(EA. 227 In the infantile diarrhoea above alluded to, it is requisite to give particular injunctions respecting the diet; for it is upon the food that has been already given, that the existing malady very often depends. It being only after birth that the digestive organs begin their functional activity, the digestive powers of the infant are in their very incipient stage of ac- tivity, and are tlius only adapted for a while for the mildest form of food. The weakness or susceptibility, indeed, of the alimentarj^ canal that exists at this period is shown by the manner in which a child at the breast is often affected by a slight indiscretion, as regards eating and drinking, on the part of the mother. When the food j)rovided by nature for the first period of life is changed — or the child is weaned, the transition should be gradually made ; and not until after the more easily digestible articles of food have been for some time given, should those that are more difficult of digestion be allowed. And yet, ignorance of the laws of life is found to prevail to such an ex- tent, especially amongst the poorer classes, that it is not uncommon to hear that anything, whether it be green vegetables, salt meat — or indeed it does not signify what — that comes to the parents' table, is given to a child that has only just been weaned, or even to a child that is still being suckled. The mother seems to have no»idea that the digestive pow- ers of her infant are weaker than her own, and won- ders what it can be that has set the system wrong — has produced the illness for which the child is brought to be treated ; but w^ith its imperfect masticatory or- gans and immature digestive powers, it is not sur- 228 DIARRHCEA. 1 prising to find that a disordered state of the stomach and bowels has been induced. The point of first im- portance to be attended to in such cases is to restrict the diet to the most easily digestible articles of food. Without this, no medical treatment will prove of any avail. Speaking of the ignorance that may prevail upon the subject of food, I once met with a child in my out-patient practice that was being brought up by hand upon arrowroot and water! The mother had lost her milk, and was feeding her infant in this w^ay, having ahvays heard as she said that arrowroot was considered an exceedingly nourishing article of food. It is not surprising, as this had been carried on for some little time, that the child w^as one of the most emaciated I have ever seen. CONSTIPATION. The residuary matter that escapes digestion and absorption requires to be expelled from the alimen- tary canal, and for the maintenance of a healthy state such expulsion must be periodically eifected at not very lengthy intervals. One alvine evacuation daily is what is customary with most individuals. With some persons, however, two, or even more, dejections during the twenty-four hours may form the rule, a state of discomfort being experienced should the ac- customed frequency fail to be observed. With others, on the other hand, only one action may take place every second day, or even longer, and still be con- sistent, if of regular occurrence, with a perfect state of bodily health. With the above preliminary statement, constipa- tion may be defined as a prolonged retention of the feeces, with more than ordinary difficulty in expelling them. It constitutes one of Cullen's symptoms of dyspepsia; and, popularly, is often confounded with, or looked upon as sj^nonymous with, indigestion. It certainly forms a result of deranged action of a por- tion of the digestive system, and frequently, though still not by any means universall3^ accompanies in- digestion in the ordinary acceptation of the term. 230 CONSTIPATION. Instances of constipation are not uncommon where intervals of several days, or one or two weeks, and even more, are found to occur between the motions that are passed. Instances, however, have been placed on record where intervals of an almost incredible duration have occurred — intervals, for in- stance, that could be reckoned by months instead of only by weeks or days. A case is quoted from a French source, by Dr. Copland, in which, from the ear- liest period of life, stools were seldom passed oftener than once in one or two months ; and at the age of forty-two the time was usually prolonged to three or four months. The subject of the case was a medical officer in the French service. He died at the age of fiftj'-four, and on examination after death a fibrous partition was found obstructing the rectum about an inch above the anus. Above the source of obstruc- tion the rectum was so enormously distended as to fill up the pelvis and a great portion of the abdomen, which had assumed a very large size. The lower part of the colon was enlarged to the size of the stom- ach. It is stated that the colon and ccecum, in other cases of constipation, have been sometimes found to measure from twenty to thirty inches in circum- ference. Constipation, in a general way, is more common in females than in males ; and females of a delicate habit of body, with a weak or atonic condition of muscular fibre, are more prone to it than others. Sedentary habits also form a predisposing cause. The most common immediate cause of constipa- tion, is a torpid condition of the parts administering CONSTIPATION. 231 to fecation. Willi the secretion of tlie colon defective in amount, and its muscular coat in a sluggish or re- laxed state, favorable circumstances are presented for an undue retention of its contents. These, by the process of absorption that goes on, become reduced to a state of preternatural consistence, and are thus rendered more and more difficult of expulsion the longer they are retained. In the constipation which forms an accompaniment of colic from lead poisoning, a contracted instead of a relaxed state of the muscular coat is believed to ex- ist, and to form the cause of the phenomenon. Through the resistance offered to the transit of matter along the intestinal canal by the existence of a spasmodi- cally contracted state of its muscular coat, constipa- tion would be looked for as a natural result. Kelief, accordingly, in this form of constipation, is found to be afforded, not by powerful purgatives, but by meas- ures directed towards removing the spasmodic muscu- lar contraction, which is at one and the same time the source of the colic and the constipation. There are various conditions which produce consti- pation in a mechanical way, by either obstructing the passage of the intestine or interfering with the per- formance of defecation. Obstruction to the passage of fecal matter along the intestine, for instance, may arise from the lodg- ment of scybala or intestinal concretions within the intestinal canal ; from structural disease in the walls of the intestine, leading to a constriction of the pas- sage ; or from compression or constriction arising from causes external to the canal itself — such as the 232 CONSTIFATIOX. pressure of the gravid uterus, a tumor, or an abscess, and the constriction arising out of a hernial protru- sion, or produced by a band of adhesion, or something of this kind, within the abdominal cavity. The performance of defecation may be interfered with through the existence of hemorrhoids, which form a frequent source of constipation. Fissures of the anus also impede defecation, and so lead to con- stipation, but in another kind of way. Through the reflex influence of the irritation arising from the fis- sure, the sphincter muscle is kept in such a forcible state of contraction as to offer an unnatural resistance to the expulsion of matter from the rectum. Constipation as an habitual derangement is only viewed in general as an affection of minor importance, and for its removal some household aperient is gen- erally kept, and had recourse to. When constipation, however, does not yield to the remedies employed, but begins to show signs of being of an insuperable nature, it becomes a grave and urgent affection, being one that may be followed by the most serious conse- quences. The morbid conditions that constipation may occa- sion are of various kinds. Under an undue retention of fecal matters within the colon noxious products may be formed there, and act as irritants upon the mucous coat, setting up in- flammation, followed by ulceration. It is to be here remarked that fecal matters are sometimes retained in the sacculi or pouches of the colon, and may give rise to the consequences referred to, whilst a passage exists along the centre of the canal that shall permit CONSTIPATION. 233 a daily evacuation to occur. The dejections, even, may be loose in character, and still the same sequence of events ensue. From the irritating influence of preternaturally retained faeces, colicky pains are, as a rule, induced, and the ultimate effects mav be such as to lead to the production of fatal ^inflammation. The effect of constipation upon the muscular coat of the bowel is, through the distension to which it is subjected, to weaken or deteriorate its evacuating power. As the result of a great amount of distension, like as happens in the case of the urinary bladder, more or less complete paralj^sis is induced. From the prolonged retention of fecal matter accom- jDanying constipation, excrementitious products that ought to be eliminated become absorbed and thereby contaminate the contents of the circulatory system. As the result of this contamination, the secretions become vitiated, and a general disturbance of the functions of life is produced. The action of the liver becoming deranged, its eliminative office is imperfectly discharged, and thus sallowness of the face and a bilious-tinged conjunctiva are produced. A coated tongue, foul moutli, loss of appetite, and other dys- peptic manifestations, accompany the general disorder of the digestive organs that prevails. The accumu- lation existing in the colon leads to a sense of disten- sion and uneasiness in the abdomen. The kidneys vicariously discharge products that ought to have been eliminated by the alimentary canal. In this manner the urine becomes preternaturally loaded. From the contaminated state of the blood the functions of animal life also become disturbed; and hence the las- 234 CONSTIPATION. situdGj debility, lieadaclie, giddiness, and dejected spirits, that form such frequent accompaniments of costiveness. Other evil consequences haA'^e yet to be enumerated as produced by constipation. Through the mechani- cal influence of the accumulated matter in the large intestine, the return of blood from the rectum is in a direct manner impeded. The deranged action of the liver, induced, as above mentioned, by the contami- nation of the .blood with excretory products, will also tend to occasion a similar state by its influence gener- ally on the portal circulation. Thus a condition is established which is prone to lead to the formation of hemorrhoids and the occurrence of hemorrhage from the rectum. A distended cgecum, colon, and rectum, may also, by the pressure exerted upon the nerves and vessels of the lower extremities, be the cause of numbness, cramps, pains, and oedema of the legs. The oedema occasioned by constij^ation, if not exclusivelj^ con- fined to one side, will in all probability be decidedly greater in one leg than the other. The undue straining efforts at stool, again, which constipation calls forth, may lead to haemoptysis in the young, and apoplexy or hernia in the aged. In the treatment of constipation occurring as a manifestation of functional derangement, and it is to this form of constipation that the remarks on treat- ment will be here confined, the object in view is to excite the glands and muscular fibres of the large in- testine into increased activity. This is eflected by the class of remedies denominated purgatives, which CONSTIPATION. 235 includes a great variety of agents, differing considera- bly in degree of power and in precise mode of action from each other. It is the laxative group, or milder form of purga- tive that is usually required in cases of constipation, and moderate doses, repeated at short intervals, are better than larger doses at longer intervals. A vio- lent action is succeeded by the j^i'oduction of an op- posite condition, and it is the occurrence of torpor which it is so desirable to prevent. The effect that is wanted is not an occasional violent action, but a continued moderate activity of the bow^els. Instead, for instance, of a couple of aperient pills being taken together at bedtime, which it may be presumed in the ordinary way will be followed by free purging the next day, one pill, repeated as often as occasion may require to obtain and keep up a periodical movement of the bowels, will be attended with a far more salu- tary result. In a matter of this kind, such a variable amount of artificial aid being required in different in- dividuals to produce the effect desired, the personal experience of the patient must be consulted as a guide. The assistance afforded should be just such as suffices to bring about the accomplishment of what nature ought to perform, and no more. A great variety of agents are placed at the disposal of the practitioner for the removal of constipation. Ehubarb, colocynth. and aloes, are valuable reme- dies, and very largely used. Podophyllin, a more recently introduced medicinal agent, is also in extensive use. Its effect,' however, is somewhat uncertain ; for, whilst its action in some 236 CONSTIPATION". cases is everything that could be desired, in others it may be followed by very violent disturbance. Senna is a safe and excellent purgative, and the syrup of it, prepared according to the " British Phar- macopoeia," has this advantage, especially for admin- istration to children, that it is not an unpalatable preparation. Dried ox-gall used in the form of pill often produces, without any discomfort, just the effect that is re- quired in cases where it happens that the bowels are not over difficult to move. Sulphur relaxes without occasioning any griping or distress, but it only forms a remedy of very mild energy. Various saline agents are also used as purgatives. Seidlitz powders and the granular effervescing citrate of magnesia form agreeable and popular preparations of this class, but they are often very far from active enough for what is wanted. What is ordinarily sold as the granular citrate of magnesia in reality, it appears, consists of the citrate of soda; this, the druggists say, being preferred by the public on ac- count of being free from the slightly disagreeable taste which belongs to the magnesian salt. Messrs. Bullock and Reynolds, of Hanover Street, prepare a granular effervescing saline aperient, which consists of tartrate of soda with a little citric acid and sul- phate of magnesia. It may be regarded as a kind of Seidlitz powder rendered more active by the incor- poration of sulphate of magnesia, and is not un- pleasant to take. Certain mineral waters act very desirably in many CONSTIPATION. 237 cases of constipation. The Piillna water contains sulphate of magnesia as its active ingredient. A tumblerful taken before breakfast and repeated a few mornings will generally afford the relief that is de- sired. The Carlsbad and Marienbad waters enjoy purgative properties which they owe to the sulphate of soda. They are less active than the Piillna water, and are, further, of an alkaline nature. In cases of constipation where a very strong agent is required, recourse must sometimes be had to cro- ton oil. Enemata are in much more common use in France than with us. An enema of tepid water or weak gruel often very effectively unloads the larger bowel, and has the advantage of not producing the slightest general discomfort. The addition of a tablespoonful, or a couple of tablespoonfuls, of common salt, in- creases its efficacy. Castor-oil and other aperients, also, are sometimes advantageously employed under the form of enemata. The most suitable period for the administration of an aperient depends upon the nature of the agent employed, it being, as a rule, desirable to avoid dis- turbing the patient by causing the bowels to be moved during the night. For the saline purgatives, which are not long in producing their effect, the best time is the morning; and if taken on an empty stomach, as the first thing on rising, their utmost efficiency is elicited. The ordinary form of aperient j)ill is customarily taken at bedtime, and in the usual way is followed by an action the next day. In ha- bitual constipation a pill of moderate strength, taken 238 CONSTIPATION. with the food and repeated daih', as occasion is found to require, produces the best effect. The cathartic, traversing the intestine with the alimentarj^ matter, forms the means of stimulating the glands and mus- cular fibres to an increased degree of activity. Such a pill — dinner-pill, as it is popularly styled — may advantageously consist of tWo or three grains of aloes, or compound rhubarb or compound colocyntli pill, with a grain of capsicum. The gourmand has re- course to his dinner-pill to hasten the transit of the ingesta through the alimentary canal ; and so to escape the evil consequences that might otherwise arise from his indiscreet indulgence. Tlie contents of the colon, as the result of pro- longed retention, may become of so hard a consist- ence, that purgatives administered by the stomach, and even purgative enemata, may fail to procure a dislodgment, and mechanical means require to be had recourse to, to effect their removal. It is especially amongst aged females of a lax or flabby habit of body that such extreme instances of constipation are most likel}^ to occur. The patient may have no idea that the bowel is impacted in this wa}', from the circum- stance that some action has been previously occasion- ally obtained ; and the practitioner requires to be on the alert to guard against mistaking the fecal accu- mulation in such cases for an adventitious growth, as such before now, through insuflicient investigation, has been done. The extract of nux vomica and compound gal- banum pill (Pilula Assafoetidse composita, as it is now called in the "British Pharmacopoeia") often form CONSTIPATION. 239 useful adjuncts to an aperient; and much assistance is frequently rendered towards the relief of costive- ness by medicinal agents that are calculated to im- prove generally the tone of the sj'stem — by a course, for instance, of ordinary tonics. The cold shower or sponge-bath in the morning, and exercise — especially horse exercise — form measures that often tend con- siderably to help the action of aperients in regulating the bowels. Friction applied to the abdomen forms also a measure that may sometimes afford assistance. With a large and pendulous abdomen benefit is ob- tained from wearing a belt, for the purpose of afford- ing artificial support. Electricity has been sometimes had recourse to in cases of constipation. Dr. Abercrombie relates a case in which, it seems, the employment of galvanism proved very successful. The bowels had resisted the influence of the strongest purgatives, except when assisted by repeated and strong injections. Galvan- ism was applied to the part of the abdomen which was hard and tense, and was almost immediately followed by a copious evacuation from the bowels. Continued daily for about ten days, it was uniformly followed by the same result. After a few minutes' application there usually commenced a commotion, with a rumbling noise in the abdomen, this being soon followed by a copious evacuation. Assistance is given in the treatment of constipation by attention to the diet. Fresh, or succulent vege- tables and fruits are the most relaxing of all kinds of food. Bread, biscuit, rice, hard-boiled eggs, and meats and fish that have been salted and dried, are. 240 CONSTIPATION. on the other hand, to be classed as the most astring- ent. Bran is of an indigestible nature, and a slight irritant to the alimentary canal. Hence, the ex- planation of the influence of brown bread in tending to produce a relaxing effect upon the bowels. In an irritable state of the digestive tract, indeed, it may so stimulate the glandular and muscular structures of the canal as actuallj^ to produce diarrhoea. Experi- ence shows that the consumption of brown instead of white bread will often just suffice to obviate the oc- currence of constipation. Constipation is in many, perhaps, in the majority of instances, primarily induced by a want of attention to the observance of regularity in the action of the bowels. It is quite as essential to health and com- fort that regularity should be observed in the dis- charge of the egesta as in the cousumption of food. No part of the system can be more thoroughly brought in subjection to the influence of habit than that con- nected with the function of defecation. A daily habit of evacuating the bowels at a stated period having been established, as the time comes round a feeling of desire is experienced ; and, should the accustomed respondence fail to be permitted a sense of discom- fort will for a time be induced. The habit in question should be begun with and enforced by parents and nurses from the earliest period of childhood. Where neglect is allowed to prevail, the bowel, becoming accustomed to over-distension, fails to give the natural warning until accumulation has taken place to an extent sufficient to render the process of defecation unnaturally difficult. As time CONSTIPATIOX. 241 wears on, matters gradually become worse and worse, a host of secondary evils are induced, and ultimately the bowels refuse to act without some kind of artifi- cial stimulus being supplied. In such a case, a habit of reguLarity may still in the generality of instances be acquired, but determi- nation and perseverance on the part of the individual are needed for the purpose. The attempt should be made and renewed every day at the same hour, whe- ther the inclination exist or not, and likewise whether the result be successful or not. Thus, in the course of time it will with a fxir amount of probability be found, that at the appointed hour, the proper desire arrives spontaneously, and leads to the easy accomplishment of that which is required by nature to be performed. The assistance of an occasional enema or of a mild aperient course may be found necessary at first to get a movement of the bowels produced. 16 ON ARTIFICIAL DIGESTION AS A MEANS OF DISSOLYIXa MEAT FOR PRODUCINa AN ARTICLE OF NOURISHMENT FOR THE INVALID. In beef-tea, broths, and the extracts of meat pre- pared in the ordinary way, we have physiologically a very imperfect representation of an article of nour- ishment. Just those very principles of the meat, viz., fibrin and albumen, which constitute its special blood- and tissue-forming elements, and give to it its nutritive value, are left behind as insoluble products. The preparation contains the salines with the vari- ous extractive principles, a considerable proportion of which, there are grounds for believing, consist of products of partial decay — materials in course of ret- rograde metamorphosis, that are of no use as nutritive agents. Taking the extract of meat, for instance, prepared according to Liebig's process, the small quan- tity of product which he says ought to be obtained (thirty-four pounds of fresh meat yield, he states, only one pound of extract), shows how completely the bulk, or substance of the meat, which constitutes its real nutritive portion, must be rejected. If it be a nutri- tive article that it is desired to obtain from the meat, it cannot fail to be wrong in principle to adopt a pro- ARTIFICIAL DIGESTION. 243 cess of preparation that is attended with the rejection of just that portion wliich ought to be present. Having frequently seen how effectually meat can be dissolved by the process of artificial digestion, I have long wondered that it has never been turned to practical account for the purpose, and have felt con- vinced that some day or other the time must arrive for it to be so. Mr. Darby, of the firm of Messrs. Darby and Gos- den, chemists and practical pharmaceutists, of 140 Leadenhall Street, London, to whom many months ago, during some interviews I was having with him upon the subject of a new kind of food for the diabetic, I communicated the views I have expressed, at once acted upon my suggestion, and has now succeeded in producing a material of such a character as to give me grounds for thinking that the attention he has de- voted to the matter bids ftxir to yield a fruitful result. In the process of procedure adopted, the same solv- ent menstruum that is employed by nature for dis- solving meat constitutes that which is made use of. A liquid is prepared containing the organic digestive principle with the appropriate quantity of acid. The hydrochloric is the acid used ; and, this being subse- quently neutralized with the carbonate of soda, after it has served its purpose, the chloride of sodium or common salt is left in the product. About four hours is the time required, under the most suitable condi- tions, for solution to be effected. Filtration, it is found, leaves a residue amounting only to about one- tenth of the weight of the lean meat that has been taken. This residue is of a greasy nature, and doubt- 244 ARTIFICIAL OIGESTIOX MADE USE OF less consists chiefly of fat, which forms a principle that, as is well known, does not yield, under physio- logical circumstances, to gastric digestion. The product obtained when the filtered liquid has been reduced to the consistence of an ordinary ex- tract equals, roughly speaking, about a third of the weight of the meat, in a fresh and lean state, employed. The fibrin and albumen of the meat are both present, and, it is to be observed, present in such a form as to be ready at once fjr absorption. Having been dis- solved in the same kind of way as they are in the liv- ing sj^stem preparatory to absorption, no action is re- quired to be performed by the stomach. Hence such a product is peculiarly adapted to form a source of nourishment where, from any cause whatever, the digestive powers are in an enfeebled condition. The efiect of the natural process of digestion is not only to dissolve the nitrogenized alimentary princi- ples, but also to transform and render them diffusible. By virtue of the propertj^ of diffusibility thus ac- quired, they can pass, in compliance with the physi- cal Laws of osmosis, and without the exercise of any special vital absorbent action, from the alimentary canal into the circulatory system. That the process under consideration not only dissolves but likewise places the alimentary principles in the same diffusi- ble state, has been reduced to demonstration by the results obtained in the experiments with the product, that have been kindly undertaken for me by Mr. Dickson, an old pupil of Guj^'s Hospital. On account of the diffusible state in which the alimentary principles exist, absorption may also be FOR DISSOLVING MEAT FOR THE INVALID. 245 reasonably looked for when the product is introduced into the rectum under the form of an enema. Some specimens that have been sent to me by Mr. Darby have been taken by patients at Guy's Hospi- tal, and, I am informed hy Dr. Steele, the superin- tendent, have met with approval. Its solution, it must be said, does not make quite so agreeable a liquid to take by itself as beef-tea, but it is susceptible of being rendered palatable by flavoring, and may be added to beef-tea, broths, arrowroot, or any other kind of food, to increase their nutritive properties. One tablespoonful of the product about corresponds to two ounces of fresh lean meat. It is right to state that whilst the pages of this vol- ume have been going through the press I have been favored by Dr. Marcet with a copy of the pamphlet he has just published, '' On a New Process for Prepar- ing Meat for Weak Stomachs." I here learn that the same idea has been passing through Dr. Marcet's mind as through my own ; but, whilst I have been looking to the production of a material for use in a state read}^ prepared. Dr. Marcet recommends that the process of preparation should be carried on in the patient's house, as the article is wanted, just as is ordinarily done in the case of beef-tea. For my own part, I feel that such precision is required in the method of procedure as to render it hardly to be ex- pected that the process will be found to be suscepti- ble of being successful!}- carried out in the hands of the public. Since the issue of the first edition of this work con- tinued endeavors have been made to improve the 246 ARTIFICIAL DIGESTION". preparation here referred to. It has received, I am informed, employment in several quarters, and whilst in some cases it has been taken with l^enefit without any material objection being raised to its flavor, in others its taste has proved an obstacle to its use. The difficulties to be overcome have been a some- what glue-like nature and a bitter taste, and it seems that the product obtained at different times has varied considerably in reference to these points. The pre- cise cause of the bitterness has not as yet been clearly made out, but as several specimens have been ob- tained possessing it only to a very minor extent, there are. grounds for believing that practice will re- veal upon what conditions it depends, and the precau- tions required to obviate its production. Where the agent has been employed it has been found, I have heard, to afford a sense of satisfaction to the stomach like that which is derived from the consumption of solid animal food. CHAMBERS ON INDIGESTION— Second Edition— Just Issued. THE INDIGESTIONS; Or, diseases OF THE DIGESTIVE ORGANS FUNCTIONALLY TREATED. By THOMAS KING CHAMBERS, M.D., Honorary Physician to H. R. H. the Prince of Wales, &c. Second American, from the Second and Enlarged English Edition. In one handsomely printed Octavo volume of over 300 pages ; extra cloth, $3. Dr. Chambers's boolc is so widely known, and i original, and the most satisfactory treatise on the has been so generally and favorably commented indigestions with which we are acs of medical men. " Practical men," as they delight to call themselves, will be pleased with its decided verdict on all the usual remedies and the absence of all eccentricity in prescription. Men of a physiologi- cal turn— and most men are turning to physiology now — will find Dr. Erinton's physiolo>iy at once recent and sound, and his histology clear, accu- rate, and minute. Physicians will accord the author the right of speech on the ground of the immense clii.nal labor which is implied, but not literature, ^\ e .>-hoiila add that a good index fa- cilitates a prompt reference to every part of the I)oo'k..—Londo7i Lancet, December 3, 1804. A well-written and valuable book, treating upon most important suhjfcts— Buffalo Med. and Surg. Journal, December, 18G5. We welcome with great pleasure the very satis- factory treatise which comes to us from Dr. Brin- and convenient form —Br/ston Medical and Surgi- cal Journal, >iovember, 1865. This is no mere compilation, no crude record of cases, but the carefully elaborated production of an accomplished pliysician, who for many years has devoted special attention to the symptom- atology. patholOiiy. and treatment of gastric dis- eases. — Edin. Med. Jour, HENRY C. LEA, Philadelphia. FLINT'S PRACTICE-Third Edition— (Just Issued). A TEEATI^SE OX THE PKINCIPLES AND PRACTICE OF MEDICINE. DESIGNED FOR THE USE OF STUDENTS AND PRACTITIONERS OF MEDICINE. By AUSTIN FLINT, M.D., Professor of the Principles and Practice of Medicine in Bellevue Hospital Medical College, New York. Third Edition, thoroughly revised ajid improved. In one large and closely printed Octavo volume of 1002 pages ; Cloth, $6 00; Leather, raised hands, S7.00. Since the appearance of the second edition, nearly two years since, the author has been laboring assiduously to render this work more worthy of the very remarkable favor with •«hich it has been received. The present edition will, therefore, be found carefully re- vised throuo:hout, and thoroughly brought up to the level of the most advanced science of the day. I3y a slight alteration in the typographical arrangement, the very numerous additions have been accommodated with but little enlargement in the bulk of the volume, while the very moderate price at which it is ofiFered renders it one of the cheapest works now before the profession. By the common consent of the English and American medical press, this work has been assigned to the highest position as a complete and compendious view of the most advanced condition of medical science. The third edition of this most excellent book scarcely needs any commendHtion from us. The volume, as it stands now, is really a marvel : first ofall.it is excellently printed and bound — and we encounter that luxury of America, the ready-cut pages, which the Yankees are 'cute enough to in- sist upon — nor are these hy any means trifles ; but the contents of the book are astonishing. Not only is it wonderful that any one man can have grasped in his mind the whole scope of medicine with that vigor which Dr. Flint shows, but the condensed yet clear way in which this is done is a perfect literary triumph. Dr. Flint is pre- eminently one of the strong men, whose right to do this kind of thing is wt-U admitted: and we say no more than the truth when we affirm that he is vei-y nearly the only living man that could do it with such results as the volume before us. — The London Practitioner, March, 1869. This is in some respects the best text-book of medicine in our language, and it is highly appre- ciated on the other side of the Atlantic, inasmuch as the first edition was exhausted in a few mouths. The second edition was little more than a reprint, but the present has, as the author says, been thoroughly revised. Much valuable matter has been added, and by making the type smaller, the bulk of the volume is not much increased. The weak point in many American works is pathology, but Dr. Flint has taken peculiar pains on this point, greatly to the value of the hoo^.— London Med. Times and Gazette, Feb. 6, 18G9. HARTSHORNE'S ESSENTIALS-Now Ready. ESSENTIALS OF THE PRINCIPLES AND PJUCTICE OF MEDICINE. A HAND-BOOK FOR STUDENTS AND PRACTITIONERS. By henry HARTSHORNE, M.D., Professor of Hygiene iu the University of Pennsylvania, &c. Second Edition, revised and improved. In one handsome Royal \1mo. volume of A-yl pages, clearly j^rinted in small type; Extra cloth, $2.38; Half hound, $2.63. This is a small size octavo of -152 pages, contain- ing an admirably condensed summary of the prin- ciples and practice of medicine. We do not hesi- tate to say that this work of Dr. Hartshorne is the very best of its kind. — Chicago Med. Examiner. March, 1869. It is simply a medical primer, a first-class book, and contains the outlines of the science and art of physic; and, as such, is of the very best quality. It is much superior to any other work of its sort ; and. if rightly used, will be found hisihly useful. Dr. Hartshorne not only knows what others have done or are doing, but he uses wi.sely his faculties of observation and rea.son. and has very decided opinions of his own, which he dues not hesitate to express, even when in opposition to the current doctrines of the day. — JSew York Med. Journal, March, 1869. Sometimes more is said in a paragraph by one than in a chapter by another. Karuest endeavor at perspicuity and terseness, with a methodical arrangement of facts, avoiding all unnecessary repetitions, will enable a qualified writer to con- dense a subject even so complex in its bearings as practical medicine, into a comparatively small space, and in such a manner as to be very useful to the practitioner in recalling his past reading, and to the student in enabling him to grasp sub- jects more easily than he would be able to do with a large treatise. Of this character is the book of Dr. Hart.«horne : no matter to what important disease the reader turns, he finds it brought out in miniature, so that its features may be recog- nized nearly as well as in a larger portraiture. The country practitioner will find it a useful and readily portable companion. — American Journal of Pharmacy, March, 1869. HENRY C. LEA, Philadelphia. A^ UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. BIOMEO LIB. 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