Nutrition in health and disease

Front matter

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RADFORD LIBRARY,

no. 0 /OdTY

I. A Practical Treatise

ON

INFLAMMATION OF THE UTERUS,

ITS CERVIX AND APPENDAGES ;

AND ON ITS CONNEXION WITH UTERINE DISEASES.

8vo, pp. 532, 3rd Edition.

II. x

A REVIEW OF THE PRESENT STATE OF UTERINE PATHOLOGY.

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1 Uric Acad .

2. Urate of Ammonia.

3. Oxalate of Lime.

4*. BiLasic Phosphate.

5 ’Epithelial Scales 6. 'Fibrinous Casts. •7. Pus Globules.

8. Blcyjd Globules

NUTRITION

HEALTH AND DISEASE.

LICENTIATE OF THE ROYAL COLLEGE OF PHYSICIANS, PHYSICIAN-ACCOUCHEUR TO THE ROYAL FREE HOSPITAL, ETC.

LONDON:

JOHN CHURCHILL, 11, NEW BURLINGTON STREET.

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LONDON

paternoster row.

Chapter IV

DEFECTIVE NUTRITION, FROM DEFICIENT VITAL POWER — FROM TIIE EXISTENCE OF ACUTE DISEASE FROM AN INSUFFI-

CIENT SUPPLY OF FOOD — FROM THE ABUSE OF ALCOHOLIC BEVERAGES — FROM AN OVER-SUPPLY OF FOOD — FROM SYM- PATHETIC REACTION ON THE DIGESTION — FROM FUNC- TIONAL DERANGEMENT, OR FROM ORGANIC DISEASE OF THE DIGESTIVE ORGANS 76

VI

CONTENTS,

Preface

My object in writing the following work has been forcibly to draw attention to the fact, often overlooked, that the imperfect performance of the digestive and nutritive functions leads, slowly but surely, to ill health, to disease, and to death. In order to make myself perfectly intelligible, I have prefaced the pathological details into which I have entered with a brief account of normal digestion and nutrition, as elucidated by modern physiological and chemical research.

The physiological facts and doctrines advanced are those generally received, and will be found more or less developed in all recent treatises on physiology. I am fully aware that some of these doctrines are still a subject of discussion between recent experimentalists, but I have not thought it desirable to vm

PREFACE.

reproduce their different opinions. Had I done so, I might have rendered the -work more complete, but I should have also marred the brevity and clearness by which I am desirous it should be characterised.

The pathological facts and opinions brought forward are deduced from my own individual experience, and were briefly enunciated ten years ago, in the second edition of my work on Uterine Inflammation, published in 1848. They agree, in the main, with the views entertained by most modern writers on nutrition and on urinary deposits.

There is, however, one point on which I join issue with many who have specially treated of urinary deposits. I believe that too much importance has been attached to the differential diagnosis of the different morbid salts which are found in the urine as a result of disordered digestion and nutrition. I attribute even more importance to the presence of these deposits, as evidences of perturbation of the digestive and nutritive processes, than is usually attributed to them; but after many years’ research, I have not been able to establish to my own satisfaction that the different morbid salts have always, or indeed generally, a different pathological meaning.

PREFACE.

IX

It appears to me that, in disordered nutritive states, all, or nearly all, may occur and constantly do occur under the same circumstances.

If such is the case, the prevailing views in this very important department of pathology may possibly admit of simplification, and be thereby rendered more practical. It is with no slight hesitation that I have made an attempt in this direction; but I have gathered courage from the reflection that the generalizations of a practical physician, who is constantly seeing and treating chronic as well as acute disease, may not be without some value, even in a field occupied by much more learned labourers.

I trust that I shall not he considered presumptuous, if I express the hope that this little work may contribute to convince my medical brethren of the imperative necessity of studying dietetics in connexion with chemistry and physiology. Apart from such a basis, all dietetic views and regulations must be fallacious. No medical practitioner is, in reality, capable of regulating the diet of his patients in a sound and satisfactory manner, unless he know and bear in mind the chemical nature of

X

PREFACE.

the food that he recommends, what it is destined to effect, and what eventually becomes of it, — whether perfectly or imperfectly digested.

In conclusion, I would remark, that the tendency which is rapidly gaining ground to look upon the diseases of the present day as presenting an asthenic character, and as requiring high feeding and stimulants more than depletion and a low diet, renders this knowledge all the more necessary. It should ever be remembered, that to give a large quantity of food to a patient, however weak and emaciated, which he cannot and does not properly digest, is partially to poison him. On the one hand, imperfectly digested food does not nourish; on the other, it has to be eliminated from the economy as noxious matter ; — yet this is an error which is constantly committed.

Chapter I. Digestion And Nutrition In Health

Under the general term of Nutrition may be comprised the various functions and operations through the agency of which the animal economy is developed, its waste is repaired, and its heat is maintained.

Life begins in man, as in all animated nature, by a cell or a series of cells. During foetal life the materials of nutrition are elaborated and supplied by the mother. But from the moment that parturition has taken place, that the link which united mother and child has been severed, and that the latter begins to live an independent existence, its nutr m must be the result of the action of it3 organisation upon “the materials of nutrition” supplied from the outer world.

The materials of nutrition are obtained from the atmospheric air breathed and from the food

B consumed. Out of these materials the organization of the new-born child, perfect in itself, but rudimentary in its development, has to be increased, completed, and repaired.

The human frame is composed, chemically speaking, of gases, oxygen, hydrogen, and nitrogen, of carbon, and of various inorganic salts, phosphate, and carbonate of lime, sulphur, chloride of calcium, &c. These are the chemical elements which are eliminated from the air and from food. The nutritive elements supplied by the atmosphere which surrounds the earth, through the function of respiration, are always the same, and if the atmosphere is pure, are supplied in the same proportions. They are beyond our control, inasmuch as respiration is carried on from birth to death independently of the will. Food contains the required chemical elements of nutrition in variable proportions, and instinct guides man, and all animated beings, in the choice of the kind of food required by his and their organizations. This instinct, however, may be, and often is, marred or perverted in man. Having reason to guide and direct him, the food-instinct is not so strong with him as it is with the brute creation, the members of which generally limit themselves to the kind of food upon which nature has intended them to live

DIGESTION AND NUTRITION IN HEALTH.

and thrive. It behoves man, therefore, to make use of his reason, to study himself, and thus to enable his intellect to direct his appetites and fooddesires.

The body is principally formed of the three gases above enumerated, oxygen, hydrogen, and nitrogen, and of carbon, transformed and solidified by nature;s chemistry. The inorganic salts occupy a subordinate but indispensable position. These salts are mainly employed in forming and giving solidity to the tissues, bones, cartilages, muscles, &c. They are contained in greater or less, but in sufficient quantity, in the various articles of food consumed by animated beings, so that they enter the economy with the food, imperceptibly, mysteriously, as it were, perform their duty, and are eliminated, without the individual having to look for them, or beingconscious, indeed, of their presence, or of the inorganic requirements of his own organization.

In the vegetable world, carbon is the all-important and predominating elementary substance. Hydrogen and oxygen also exist in abundance, either united as water, or in other forms of combination. Nitrogen is scarcely found in some vegetable productions, and seldom constitutes more than from one to four per cent, of the whole, even in the vegetable substances which contain it in the largest proportion, such as wheat, oats, hay, &c. In the animal world, nitrogen appears to be in the ascendant, and to constitute the most important element in the animal formation ; carbon, oxygen, and hydrogen occupying a secondary position.

Even in the animal creation, however, carbon constitutes the greater part of the bulk. Thus lean beef, white of egg, and the curd of milk, when quite dry, present the following proportions (Professor Johnston) : —

Carbon

PER CENT.

. 55

Hydrogen .

Nitrogen

. 16

Oxygen, with a little sulphur and phosphorus .

. 22

The greater amount of nitrogen contained in animal substances, as compared with vegetable, appears, however, to thoroughly modify their anatomical and physical character, and warrants the distinction generally recognised and established between carbonaceous and nitrogenous, or vegetable and animal, organizations.

This simple fact is at the bottom of the entire

DIGESTION AND NUTRITION IN HEALTH.

theory of nutrition in the organic creation. The framework of an animal being, to a great extent, formed of nitrogen, it is clear that if the animal is not carnivorous, does not live on flesh, it must consume vegetable food containing nitrogen. And such is the case ; the grains and grasses on which granivorous and herbivorous animals live, all contain, in addition to the carbon, considerable quantities of nitrogen. Carnivorous animals make and repair their nitrogenous flesh-tissues from the nitrogenous flesh of the herbivorous animals ; while the latter, as we have seen, elaborate it directly from the vegetable world. Man, occupying a medium position, and being carnivorous, herbivorous, and granivorous, can extract the nitrogen he requires either from animal or from vegetable substances, or from both simidtaneously. In the first case, he transforms directly the flesh of the nitrogenous tissues of animals into his own; in the second, he extracts from the vegetables he consumes their small per centage of nitrogen ; and, in the third, he forms and repairs his own flesh on nitrogen extracted indisci’iminately from both kingdoms. In all three, he combines the nitrogen extracted from food with oxygen supplied from the atmosphere through respiration, in the formation of his tissues.

DIGESTION AND NUTRITION IN HEALTH.

From the above facts, it must be apparent that man, a considerable proportion of whose body is composed of nitrogen, is compelled to seek nitrogen in bis food to complete bis structures and to repair their waste. Nitrogen, therefore, be does seek, and finds, in abundance, in animal substances, flesh, milk, eggs, &c., and also in a smaller ratio in vegetable articles of diet.

Man, however, like all warm-blooded animals, has not only to complete and renovate the structures which constitute bis body, — be has also, from the hour of bis birth to that of bis death, to create heat, in more or less abundance, according to the temperature of the atmosphere by which be is surrounded. Owing to the laws of radiation of heat, there is a constant tendency in all bodies, animate or inanimate, to abandon surplus beat to the medium in which they are placed. In the warm-blooded animal creation, this tendency is only counteracted by the constant generation of beat, which is a result, partly of real combustion, and partly of the more intimate vital, electric, and nutritive changes that are constantly taking place in the tissues of the economy. When death supervenes, and these operations cease, the body, at first warm, rapidly loses its beat, and becomes of the same temperature as the surrounding atmosphere.

DIGESTION AND NUTRITION IN HEALTH.

Thus, during life, the animal body is a walking fire, consuming fuel, in the shape of food on the one hand, and of its own detritus on the other, which it combines with oxygen derived from the atmosphere during respiration. In a climate like ours, a very considerable proportion of the food taken is thus consumed in keeping up the animal heat.

Combustion, in the external world, is principally supported by the combination with the oxygen of the atmosphere of carbonaceous substances, such as vegetable products, wood, charcoal, coal, &c., and fats and oils, which are hydrocarbon compounds. Their rapid chemical combination with oxygen is attended with the evolution of heat and light. Were the combination to take place more slowly, heat would still be evolved, but light would not. This is what occurs in the animal economy. The carbon of vegetable food, — the principal element of such food, — and that of fatty substances and of alcoholic beverages rich in carbon, combines with the oxygen introduced into the circulation by respiration, forms carbonic acid, and evolves heat.

Thus we see that the nitrogenous element in food, represented by flesh or animal substances, is principally required to perfect the tissues of the economy, and to repair their waste; whilst the

DIGESTION AND NUTRITION IN HEALTH.

carbonaceous element, which is represented by vegetable articles of diet, by fats and oils, and by alcoholic beverages, is principally required, as fuel, to support the silent combustion which is constantly going on in the animal system, and to which is mainly due the generation of animal heat. It is now generally admitted that the more intimate processes of nutrition, which consist in the constant formation and disintegration of the tissues of which the economy is formed under the influence of the nervous system, are also attended with the evolution of latent heat in considerable quantities. These sources of heat continue to create it incessantly as long as life lasts, ceasing their operation with life only.

Having thus briefly stated what nutrition is, and analysed the materials on which it depends, I shall now examine the various stages of elaboration through which these materials have to pass. It is not my intention, however, to enter minutely into the history of the various functions which, by their united action, constitute digestion and nutrition. I am merely desirous to give a brief sketch of the facts established by the researches of modern physiologists, in order to render intelligible the subject of nutrition in general, and more especially that of morbid nutrition.

SOLID FOOD, ITS ELABORATION AND DESTINATION.

Liquid food introduced into the mouth is swallowed at once and passes into the stomach. If solid, it has to undergo the preliminary process of mastication. During mastication it is freely mixed with the alkaline saliva, which is poured out in abundance from the salivary glands, and which much facilitates the process. Liquid food passes into the stomach with compai’atively little admixture of saliva. Solid food, on the contrary, whilst being ground and divided, is saturated with salivary secretion, which gradually forms it into a pulp fit for the action of the gastric juices. From the various experiments that have been performed, it would appear that the subsequent changes produced in solid food by the stomachal digestion are much facilitated by the presence of the saliva.

The saliva also appears to have a peculiar power of transforming the amydon or starch of farinaceous food into grape sugar, a necessary transformation in the series of food changes. This is the more remarkable as the gastric juices do not possess this power. They appear to act more especially as a solvent of the nitrogenous food element.

b 3

As soon as food reaches the stomach its presence determines the secretion of the gastric juice, which is not found in that organ during the period of vacuity or repose. This secretion exercises a very peculiar dissolving power over the food which is submitted to its action, gradually reducing it to the condition of a grey creamy or pultaceous fluid. The time employed to effect this dissolution varies according to the nature of the food ; animal substances, as a rule, taking longer to digest than vegetable.

The period of stomachal digestion is one of great vital activity for that organ. The contact of food with the coats of the stomach is immediately attended with an influx of blood to its mucous membrane, which becomes highly vascularized. In this mucous membrane are innumerable glands, imbedded as it were in longitudinal bundles in its tissue, with their orifices opening on its surface. These minute glands secrete the gastric juice, which they accomplish by the successive formation and rupture of the cells that contain it. The muscular structures of the stomach are at the same time contracting actively, so as to bring successively each portion of the food in contact with the mucous membrane from which gastric juice is pouring uninterruptedly : these contractions also carry off, towards the pylorus and intestines, that portion which has been dissolved and elaborated.

The gastric juice is acid, a property it owes to its containing lactic or hydrochloric acids, and the superphosphate of lime. Its digestive properties depend on a peculiar animal matter, to which the name of pepsine has been given, and which may be extracted in the shape of an amorphous powder. A solution of pepsine will dissolve meat or any other alimentary substance at a temperature similar to that of the body.

When empty the stomach, which may be termed in some senses a large muscle, contracts on itself ; when it contains solid food it contracts firmly on the food, and forces it round and round the large curvature of the stomach, and then back to the oesophagiac orifice by which it entered. As the food dissolves and assumes the character of a creamy pultaceous fluid, which is termed chyme, it escapes from the above-described circuit, is directed towards the pylorus, and passes into the intestines. Fluids are, in a great measure, directly absorbed by the walls of the stomach, which sift out and retain their solid constituents.

The time employed by the stomach in thus digesting or dissolving food varies according to its nature.

DIGESTION AND NUTRITION IN HEALTH.

and according to the individual. Various means have been resorted to with a view to solve this question : animals have been killed at different hours after tbe ingestion of food ; food has been placed in hollow perforated balls and tied to a string, by means of which they could be withdrawn at any time ; or vomiting has been artificially induced. The most conclusive experiments, however, were those of Dr. Beaumont, of New York, on a young Canadian, which have been quoted by all recent physiologists. Dr. Beaumont’s patient, a healthy young man, had received a gunshot wound just over the stomach, which exposed and opened that organ. The wound, on healing, left a wide fistulous perforation, which had to he closed artificially. On removing the plug or artificial covering the food could, at any period of digestion, be removed and examined, and the state of the stomach and of its secretions could be investigated.

Dr. Beaumont went, through a very extended series of observations with his patient, and came to the conclusion that cooked vegetables and fluid animal substances were easier and sooner digested than flesh ; and that the comparative rapidity of the digestive process depends principally on the degree of cohesion of the tissues exposed to it, that is, on their tenderness or toughness. According to the table published by Dr. Beaumont, the following were the principal results noticed : — rice and tripe were digested or cliymified in an hour ; eggs, salmon, trout, apples, and venison, were digested in an hour and a half ; tapioca, barley, milk, liver, fish, in two hours ; turkey, lamb, potatoes, in two hours and a half; fowls, beef, and mutton, in three hours and a half ; veal in four hours. The same results were obtained on macerating these substances in the man's gastric juice, out of the stomach. The results obtained by other observers have varied, more or less, according, no doubt, to individual idiosyncrasy or peculiarities, and to the state of health at the time of the experiments. From my own experiments and observation, principally directed to the state of the urine after food, I think I am warranted in giving the following list as a guide to be generally relied on in estimating the comparative digestibility of different articles of food : milk, eggs, broths, and light soups, cooked vegetables, fish, fowl, game, lamb, mutton, veal, beef, salted meat, including ham and bacon. The time occupied in the digestion of these alimentary substances, before they reach the blood, and modify the urine, varies from two hours for the lighter food — eggs, milk, broths,

&c., to five hours for the more dense alimentary substances, and more especially for salted meats, ham, beef, bacon, &c.

The chemical changes that take place in the stomach are important. The fibrin and the albumen of animal tissues and fluids are chemically acted upon by the gastric juice, and appear to be converted into a low form of albumen, from which they are later to be again elaborated. The same change probably takes place in the nitrogenous elements of vegetable food. The other elements of vegetable substances are principally sugar, gum, lignin, and amydon, or starch. The sugar, gum, and part of the lignin, which are soluble, are probably dissolved at once, and absorbed ; whilst the insoluble starch that has not been converted into dextrine or sugar in the stomach, probably undergoes that transformation in the duodenum under the influence of the pancreatic secretion. The action of heat in cooking expands and breaks the starch granules, thus rendering them more easily acted upon.

The oleaginous elements, including all oils, fats, butter, &c., are not chemically modified by the stomachal digestion ; they are merely separated and reduced to a minute state of division.

On leaving the stomach, the chyme becomes mixed with the secretions of the pancreas and of the numerous minute glands which are situated in the mucous membrane of the small intestines. The secretion of the pancreas, a gland of considerable size, is abundant, and presents the same physical properties and chemical composition as the saliva. It appears destined to perform in part the same office, as it also possesses the power of transforming into dextrine and sugar granules of starch that have escaped the action of the saliva in the mouth or in the stomach. It is also supposed that one of its offices is to prepare fatty principles for easier absorption, by transforming them into fatty acids and glycerine.

The duct from the pancreas often opens into the intestines by a joint canal with that from the liver, and when this is not the case the two ducts are in close proximity. Thus these two secretions mingle, and it is probable that the result of their union is a compound secretion possessed of peculiar properties for promoting the digestive elaboration of the chyme and preparing it for absorption by the lacteals.

The liver is a large gland, the secretion of which, bile, is very abundant. The amount of bile secreted in the twenty-four hours is variously calculated to be from half a pint to two or even three pints. The secretion is retarded during fasting, and accelerated by the ingestion of food. From the numerous and important physiological researches that have been made in modern times, it appears that the biliary secretion has a double function to perform. On the one hand it purifies the blood of carbon, the product of molecular disintegration, or a component of imperfectly digested and unassimilated chyle; and on the other it performs an important part in the digestive process.

Bile is principally composed of carbon and hydrogen, which it separates from the portal blood, loaded as that blood is with albuminous and amylaceous products directly absorbed from the food in the intestines. Thus the portal blood is purified by a process which we may partly compare with respiration; which, under certain circumstances, it may partly or wholly replace. In respiration the carbon and hydrogen in excess in the venous blood combine witli the oxygen of the atmosphere, and form carbonic acid and water.

In the liver the carbon and hydrogen of the portal blood are merely transformed by the secretive process into bile. In both cases, however, the venous blood is purified. During foetal life the purification of the blood appears to be entrusted to the liver only, and on birth the intestinal canal is found filled with bile in the shape of meconium. In warm climates.

and even in temperate climates, when the weather is warm, respiration is less active, and consequently less efficient in purifying the blood of its carbon and hydrogen. As a compensation the secretory activity of the liver increases, and hence, partly, the frequency of liver disease in these climates and seasons.

During digestion, bile, which thus flows into the small intestine along with the pancreatic fluid, mixes with the chyme shortly after it has passed out of the stomach. This mixture of the bile with the chyme no doubt modifies its character, and fits it still further for its absorption by the lacteals. It operates also as a stimulus on the entire intestinal canal, promoting its action and the excretion of the residue of the food, as shown by the constipation which accompanies jaundice, when the excretion is temporarily arrested; and the diarrhoea which follows bilious fluxes. It is worthy of remark, however, that in health the greater part of the bile is reabsorbed in the intestinal canal, not more than one-sixteenth passing away with the motions.

The chyme, or food which has undergone the stomachal digestion, becomes alkaline, instead of acid, after mixing with the pancreatic and biliary secretions ; it is, also, more homogeneous, more consistent, and darker in colour. Thus elaborated, it has become fit for the absorbent process which now commences. The soluble portions of the chyme are successively presented to the surface of the small intestine as it is propelled along its course, and are absorbed principally by the lacteals, but also partly by the veins. The lacteals are very numerous in the small intestine, and more sparse in the large. By this process the albuminous, fatty, and saccharine elements are taken up, as also the bile and the salts in part. What remains and is expelled from the body, as faeces, consists, or ought to consist, only of the non-nutritive part of the food, viz. woody fibre, vegetable and animal epidermic detritus, mucous corpuscles, colouring matter of the bile, fat, starch unmodified by the digestive process, salts, &c.

The chyle which at first fills the lacteals presents the appearance of a milky fluid. This appearance it owes to the fatty globules, in a minute state of division, which it contains. These globules are supposed to be surrounded with albumen, which prevents their coalescing. The fluid in which they swim contains albumen in solution. After it has passed through the ganglia to which the lacteals converge, this fluid presents corpuscles similar in form to those of the blood, to which the name of chyle corpuscles is given. Fibrin is also found in the chyle, which has evidently been formed out of the albumen of the chyle. The chyle corpuscles become more and more perfect, and more like true blood corpuscles as the chyle advances towards its destination, the jugular vein ; until in the upper portion of the thoracic duct, they often assume the red colour of the latter. The fibrin also increases in quantity in the same proportion. Thus the more the chyle, the result of the digestive process, approaches the point at which it is thrown into the current of circulation, the more it assumes both the microscopic and chemical characteristics of the blood, which it is evidently destined to renew.

By this same channel, the thoracic duct, is also thrown into the current of circulation the fluid collected by the lymphatic vessels from all parts of the body. These vessels, originating in nearly all parts of the economy by minute radicules, pass through gauglia like the lacteals, and converging, finally terminate in the thoracic duct. They contain, at first, an albuminous fluid like the lacteals, but clear instead of milky, owing to the absence of the fatty particles. Lymph corpuscles and fibrin appear on their emerging from the ganglia, and both the perfection of the first, and the quantity of the latter

DIGESTION AND NUTRITION IN HEALTH.

increase as they approach their termination. The lymphatics, like the lacteals, evidently perform an important part in the renewal of the blood ; but, unlike the lacteals, the renovating elements they contain and elaborate are drawn, not from food, but from the blood itself, and the tissues it creates.

To complete this sketch of the sources from which the blood, the grand element of nutrition, is derived, we must not forget that, as we have seen, part of the chymous fluid is absorbed by the intestinal veins, and is carried directly by the portal vein to the liver, and that there it is elaborated and eliminated in the shape of bile ; the greater portion of this bile being again absorbed in the small intestine.

Thus we find the chyle which enters into the circulation by passing from the thoracic duct into the jugular vein is, in reality, new blood. This new blood is elaborated out of the chyme and bile absorbed in the intestines and out of the fluid brought by the lymphatic vessels from the capillary tissues. The quantity of chyle thus contributed in the twenty-four hours is very considerable, amounting, it is supposed, to as much as one-third or onefourth of the weight of the blood contained in the body. This fact proves how rapid and constant must be the nutritive processes, for the weight of the blood of a healthy adult is supposed to be about twenty-eight pounds.

The new, or lacteo-lymphatic blood, reaches the right heart along with the venous blood, returning from the different parts of the body. It is propelled by the right ventricle into the lungs, and as it passes through the capillary vessels which form the connecting link between the pulmonary artery and vein, it comes in contact with the atmospheric air, introduced by respiration into the pulmonary cells, around which the capillaries in question are spread. It is at this stage of the pulmonary circulation that the chemical changes of respiration take place; changes which modify the air inspired on the one hand and the blood on the other.