Kitabı oku: «The History of Salt», sayfa 6

CHAPTER VII
MEDICINAL AND DIETETIC PROPERTIES

Salt, except by the ignorant, is generally acknowledged to be a condiment, not only requisite as an adjunct to food, but also for the animal economy; this fact is not to be lost sight of, and therefore I lay much stress on it, and in the next chapter we shall see that physiologically it holds no mean position amongst those other substances which are found in the human body.

There are a number of facts of physiological import, at which it is necessary to glance, and which are indissolubly connected with its medicinal and dietetic properties; and there are various others illustrative of the absolute necessity of salt, which are self-evident to those who think and observe, and which we will now proceed to lay before the reader.

In human blood, salt is a most important constituent; where there is disease, there is a diminution of salt, with corresponding nervous depression, and the individual experiences a want of power: if this want continues for any length of time, the health is gradually undermined; the blood loses its richness and is deprived of its vitalising property; various symptoms finally show themselves, and probably develop into some phenomena of a serious significance – all, indeed, indicative that the system is deficient of a most important essential in its economy. These symptoms may prognosticate the approach of various diseased conditions, partly owing to the habits, constitution, or surroundings of the patient. In all morbid conditions, and particularly in those which owe their origin to an unhealthy state of the blood, we may, to a considerable extent, be certain that there is a deficiency of the chloride of sodium. In proof of this, patients never, as a rule, object to salt; they actually relish it. Why? Because there is a deficiency, and nature intuitively excites the desire. We often find that patients refuse sugar; indeed the very mention of it produces a feeling of nausea and extreme disgust: with salt it is entirely different; they take it, and, in most cases, enjoy it in the same way that fever-stricken patients long for, and relish, a draught of cold water, if they are able to obtain it.

Were the human race once deprived of the chloride of sodium, even for a limited period of time, we should not only lose a natural healthful incentive for our food, but disease, with all her attendant miseries, would spread with such relentless impetuosity as would defy, and even paralyse, the efforts of the most skillful physician, the ingenuity of the surgeon, and the scientific improvements and hygienic precautions of the sanitarian.⁵³ The strength and vigour of manhood would fade as if blasted by disease, food would act as a poison; the blood would not be replenished with the salt which it requires, and consequently our skins would soon be covered with corruption; our cattle would die, our crops would be nipped in the bud; the air would be full of offensive insects; the soil would become foul and barren, the sea a waste of stagnant waters; and all the beautiful productions of nature would wither and decay, and our glorious earth would degenerate into a hideous solitude, solely inhabited, very probably, by monsters horrible to behold, and more repulsive than those gigantic reptiles which once roamed by the dreary marshes of an incomplete world.

Those who take pleasure in decrying the inimitable works of nature, and affirm that they are provocative of evil, can only support their arguments by brazen assertions and subtle paralogisms.

Common salt is considered by most persons as a mere luxury, as if its use were only to gratify the taste, although it is essential to health and life, and is indeed as much an aliment or food as either bread or flesh. It is a constituent of most of our food and drinks, and nature has kindly furnished us with an appetite for it, though there are not a few who regard it quite in another light: that quadrupeds and birds (as I have before stated) should be fully alive to the vivifying properties of salt, and that mankind should be indifferent to, and in many instances totally ignorant of them, is somewhat curious and incomprehensible, but it is so.

Another strange fact is, that savage nations use it freely with but few exceptions: on the other hand, in civilised life there are a great number who never touch it; but these abstainers little think that they carry in their countenances visible signs of ill-health, and their impurity of skin indicates that at some future time disease, in some form or other, will cause them to regret, in more ways than one, that their short-sighted neglect has prepared a soil ready to receive the seeds of some fever, and other maladies more deadly and obstinate.

Cutaneous eruptions, so distressing to the patient, and so disgusting to an observer, flourish when they attack those who have abstained from the use of salt.

Everyone perspires or sweats: the indolent perspire, the laborious sweat. This distinction will be regarded as too fine by those who entertain the opinion that perspiration and sweat mean the same thing; this, however, is a great error; there is a marked difference between perspiring and sweating, as much difference, indeed, between these two processes of the elimination of refuse animal matter, as there is between walking and running. It is true the same laws of nature are brought into play; but one is a modification of the other. Those of a spare habit are seldom in a state of general diaphoresis, and are only so when the weather is sultry, or when they have taken a walk on a hot summer’s day. The stout or plethoric, on the contrary, sweat copiously, even on the slightest movement; and it is really a good thing for them that they do, for otherwise they would very likely be attacked with a fit of apoplexy, or would fall down from syncope; the former arising from the flow of too much blood to the brain, or from rupture of an artery; the latter resulting from an insufficient supply; or the blood owing to its circulating in an impure state, which is practically the case if there is a deficiency of salt, would generate, not what is generally considered disease, but a condition which would render the system prepared for the reception and development of morbific influences.

During perspiration the blood is deprived, in proportion as the diaphoresis continues, not only of the liquor-sanguinis, but of the chloride of sodium which it holds in solution. Though to a certain extent perspiration is an act of nature necessary for the continuance of health, yet, if it goes beyond a point which is consistent with an equalisation of the several secretions, the individual experiences a diminution or loss of power, and nervous exhaustion or irritability is the result. In natural diaphoresis the only way in which the system can recuperate itself is by quenching the thirst; for free perspiration is generally or almost invariably succeeded by a corresponding thirst, varying in intensity according to the peculiar idiosyncrasy of the individual.

Thin people do not perspire so copiously as those who are more stoutly built, therefore they do not lose so much and neither do they require so much fluid. Their blood, by reason of its retaining its liquor-sanguinis and its chloride of sodium, does not require salt as an aliment so freely as those who, owing to their profuse perspiration, are in constant want of it. Stout people, or those who have a superabundance of adipose tissue (for I must observe there is a great difference between stoutness and obesity, though in common parlance the two words are synonymous), require salt in a greater degree than thin people. Well-developed muscles covering a well-made frame, accompanied by a proper and due proportion of fat, constitute stoutness of a healthy standard; but small muscles covered with an overdue amount of fat, with an abdomen distended to an offensive size (which is so frequently seen), seem, in my opinion, to determine a habit of a Vitellian obesity, if I may so apply the name of that Roman epicure.

Owing to the fact that stout and fat people perspire freely and profusely, and to a much greater extent when undergoing fatigue, they must necessarily lose a great amount of salt; for as it is held in solution by the liquor-sanguinis, which passes through the pores of the skin in the form of sweat (the word perspiration is not sufficiently emphatic when we are speaking of stout and fat individuals), it must naturally pass out with it, and thus they experience thirst and a desire for salt; which desire is strongly indicative of a healthy state of the secretions. If there is no wish for salt, then we may conclude that disease in some form or other is lurking unsuspected in the system, ready to break out, either by an act of indiscretion, poisoned atmosphere, or because of a taint of an hereditary character. We may compare this condition of things to a barrel of gunpowder, ready on the application of the faintest spark to ignite, and spread confusion and death far and wide, with a fury proportionate to the amount of the inflammatory material. If these people do not take salt with their food they allow their blood to become impoverished and more unhealthy than it already is, and their constitutions materially suffer in consequence, their skins are ultimately affected, the complexion frequently becomes sallow, and appears discoloured, and in some severe cases we have that skin disease called acnæ, indicative of the poor and unwholesome state of the blood; they are affected with intestinal parasites, they do not digest their food, their breath has a most disagreeable odour, very unmistakable, and they are more or less out of health.

Those of a scrofulous habit require salt to a much greater extent than even the gross, because the blood of scrofulous or strumous persons does not possess its due proportion of salt; and the only way to make up for this deficiency is to use it freely, otherwise the system does not derive the support and nourishment from that source which vitalises the whole frame. We may justly infer that if the blood is deficient of a most important constituent the system must, as a matter of course, degenerate into a condition not only ready to receive disease, but into one which reduces the strength and undermines the nerve-power, and this in a scrofulous habit is fraught with serious consequences.

The chronic inflammation which attacks the joints in scrofula sometimes occurs, not so much from the unhealthy low state of the system, but rather from the impure condition of the blood, resulting from the partial absence of salt. This must be the case, because the sufferer experiences an increased vitality if salt is used more abundantly; the change of course is gradual, and therefore we must not expect to see one’s efforts immediately crowned with success. It is sometimes necessary to explain to scrofulous patients the unhealthiness of a persistent avoidance of salt, and to point out to them the benefits accruing from it, and also to insist upon their using it, because, owing to their ignorance of its operation and their unwise dislike, they look upon it in the light of a noxious compound.

I have frequently noticed (and I dare say others have observed the same thing) the disfiguring eruptions with which many people (and especially the young) of a scrofulous habit, and even some who are free from this taint, are afflicted about the face and neck. These pimples and blotches, when not caused by constipation, are generally accompanied by a swollen condition of the glands, which are sometimes acutely sensitive to the slightest pressure.

If we were to question them closely we should find that salt is to them an almost unknown article of diet, or distasteful to them, though no doubt it is, in some few instances, used but sparingly and seldom.

The blood, more or less, is always undergoing a change, even in health; the nitrogenised and non-nitrogenised substances are invariably variable, and at no two moments are the salts of the same proportion, its alkalescence always being in a constant state of variation. Notwithstanding our increased facilities for obtaining a better acquaintance with disease than formerly, the few facts which have been satisfactorily made out show us that as yet we have made but little progress as regards the morbid conditions of the human blood, and that a great deal remains to be accomplished before we are masters of the subject.

Amongst the chief diseases in which a pathognomonic condition of the blood has been discovered is the increase of the fibrine, which always takes place in inflammatory diseases, such as acute rheumatism and inflammation of the lungs; in low fevers it is diminished; it is also subject to variation in other diseases. In typhoid fever the diminution of salt and the increase of fibrine is very marked; and indeed in all inflammatory states of the system, especially of a sthenic type, the partial absence or variation of the amount of the chloride of sodium is a most important characteristic. No attention has, up to the present time, been given to the relation which the presence of the chloride of sodium in the blood bears to disease, at least not that I am aware of; and from what I have noticed it opens up a question which in time will be considered of some moment. As the chloride of sodium obviates the tendency of the fibrine to coagulate, and as its coagulation or solubility is quite dependent on its normal amount in the blood, it presents to us many varied points of interest, not only physiologically, but medicinally, though in this respect it has not yet been recognised as a curative agent.

Whenever the blood is impoverished we may be tolerably certain that salt is, in a greater or lesser degree, absent, or below the standard, and that it is variable.

Now in scrofula the blood is not only vitiated, but poor in the extreme, and there is a decrease of the fibrine; and that being the case, the constitution suffers in proportion, the affection showing itself in various ways, which unmistakably indicate the adynamic state of that fluid which permeates the whole frame.

Scrofula and her twin sister struma, for there is a difference, are low forms of chronic inflammatory cachexia, and are never entirely recovered from. We may justly term them systemic diseases originating local morbid phenomena, and which are always liable to give rise to obscure attacks of an apparently serious nature, but which are considerably modified if the treatment be simply hygienic, judicious, and practical; scrofula is always tedious and prolonged, and therefore, as I have said before, we must not anticipate that because salt is of a nature somewhat antidotal to it and its attendant evils, that its effects are to be observable instantaneously, or that any very remarkable results must necessarily be obtained. It is the reverse; the effects are slow in the extreme, but the benefit is permanent – that is, if the treatment adopted be calculated to restore to the blood that constituent so necessary for health.

This is easily explained – the unhealthiness of the system arising from mal-nutrition, owing to the blood being more or less deficient of a constituent which is necessary for the promotion of health, and being solely constitutional, it takes some time to make up for that deficiency, and to supply that which is lost. A disease of long standing, and of an hereditary character, is not speedily recovered from, particularly if the mischief is caused by, or is dependent upon, an impure state of the blood, and if there is not the normal amount of the chloride of sodium it must of necessity be corrupt.

Though salted provisions are apt to produce scurvy if continued for too long a time, yet in the case of those on board ship I do not think it arises exclusively from the salt itself, but by the unwholesome food upon which the toilers of the sea are obliged too often to subsist. The biscuits, which are of the coarsest kind, and sometimes worm-eaten, are certainly not calculated to keep up the stamina of the men; and the salt pork which they have three or four times a week is not exactly the food to promote a healthy condition of the blood; neither is the soup, which is little better than rice water, capable of even satisfying the cravings of hunger.

Besides, there is a very miserable custom, and which tends to ruin the health of our sailors, and that is the drink which is, I may say, encouraged on board ship, and officially served out to them daily, in the shape of rum, though of late they can have cocoa if they prefer. So habituated have they become to this that no captain would think of suggesting a diminution of the supply. Our sailors, poor fellows! will stand anything but the deprivation of their “grog;” they do not mind being crowded like beasts of burden in a close, stifling forecastle, eating coarse biscuits or unwholesome pickled pork, so long as they are duly supplied with their “grog” and allowed to go “ashore” and spend their contemptible pittance on poisonous compounds which burn their stomachs and sow the seeds of some deadly disease, and especially if they happen to be in the tropics.

All these inseparable accompaniments of nautical life are, without doubt, provocative of scurvy to a certain extent, and I am sure do not help to stave it off. If rum is taken on an empty stomach, day after day, as regularly as clockwork, we cannot expect that the men should be in a state of sound health, or that their blood should be pure; particularly if the voyage is long, the biscuits worm-eaten, the pickled pork of a questionable condition, sometimes even approaching putridity, and the rice-soup – upon which I shall abstain from passing any remarks, further than by saying that it is decidedly not of that quality tending to act as a substantial sustentation of men who work hard, and who are exposed to all weathers, both by night and by day. Indeed it is surprising that they can perform their duties as they do when we call to mind their irregularities, their daily use of spirits, and their periodical alcoholic indulgences when ashore, combined with their abominable diet on board ship.

Though salted provisions solely are not altogether conducive to health, or contributive towards preserving the due equalisation of the constituents of the blood, I cannot see that they entirely originate scurvy, as some assert; I am of an opinion that this disease is caused principally by seamen’s peculiar habits, and the surroundings belonging to a seafaring life, joined, much more frequently than some would like to confess, with the ingestion of animal food just rescued from putrescence by a timely immersion in brine.

Everything, as is well known, can be used and abused, and salt, like other natural productions, owing to human avarice, can be put to a purpose so as to derange and render nugatory the laws of health. We know full well that salt completely arrests the formation of putrescent larvæ in meat, if it is rubbed in when fresh, or if it is well soaked in strong brine; and if the meat is bordering on decomposition, we may prevent it proceeding to a more advanced stage by immersing it in brine; still it is not in a condition fit for human consumption. Such food in my opinion is of a nature calculated to produce disease of a most virulent type; indeed it is quite sufficient to produce the worse form of scurvy, let alone the outbreaks of a milder degree.

I am acquainted with the fact that a diet consisting exclusively of salt pork and salt beef, with very little variation or change, would be, if continued for any length of time, combined with the absence of fresh vegetables, productive of much mischief, and in the end no doubt scurvy would be the result; but for us to assert that every outbreak of this disease is produced by salted provisions, is to run into a very ridiculous error, and we fall into a trap cunningly laid for us by those whose interest it is to keep up this preposterous imposition in the eyes of the not too discerning public. If shipowners took more care in provisioning their ships with wholesome food, instead of allowing them to be stored with bad pork, putrid beef, and rotten biscuits, we should not read the heart-sickening accounts so frequently in the newspapers. It is all very well for them to assert that the disease springs from salt, and the absence of vegetable food; it is to their interest to say so. We can cast their flimsy statements to the winds, however, and give them an emphatic contradiction, for their proceedings in this matter will not bear even a partial investigation.

I have gone more fully into this part of my subject than I intended, for the following reason: the advocates of total abstention from salt invariably bring forward scurvy as a conclusive proof of their argument, and as unanswerable; they have not looked at it, I am afraid, from the above standpoint, and I think if they will take the trouble to go into the matter more thoroughly, they will find that scurvy originates, not from wholesome salted provisions and the want of vegetables, but from impure and putrid food, which too many owners of ships, from pecuniary motives, prefer to supply, not for the passengers – that would of course be unwise policy – but for the men who labour for them on the waters, and who are at the mercy of employers as insatiable and inexorable in obtaining their pounds of flesh as the storm-tossed ocean yawning for its victims.

“Digestion is the process by which those parts of our food which may be employed in the formation and repair of the tissues, or in the production of heat, are made fit to be absorbed and added to the blood.”

I do not think it will be out of place to make a few cursory observations on the process of digestion, for as scurvy is the result of the ingestion of unwholesome food, we cannot do better than consider the process in relation to salt, and its action on animal and vegetable food while it is in the stomach.

When this organ is empty it is completely inactive; there is no secretion of the gastric juice, and the mucus, which is slightly alkaline or neutral, covers the surface; but immediately food is introduced, the mucous membrane, which was pale, at once becomes turgid, owing to the greater influx of blood; because when any organ has work to perform, it requires an increased supply.

The amount of the gastric juice secreted has been variously estimated to be from ten to twenty pints a day in a healthy adult, and by the following table, we find that salt, or rather the chloride of sodium, is present in a considerable quantity. Looking, then, at the immense secretion of the gastric juice, salt is really in continual requisition, making it self-evident that if the supply is not kept up in the same ratio, digestion is retarded, the food passes out of the stomach in an undigested state into the duodenum, and the stomach is consequently overstrained because of the loss of one of its most important constituents; the supply of salt not being equal to the demand.

Composition of Gastric Juice.

In a sheep’s gastric juice there is to 971·17 of water, 4·36 of chloride of sodium, showing at once how highly necessary it is for cattle to be supplied with it; a sheep will consume on the average half an ounce of salt daily; that it tends to prevent an outbreak of the rot, I have already drawn the attention of the reader.⁵⁴

There is we see 0.20 of hydrochloric acid to 994.40 of water in the gastric juice, though some are of an opinion that it is lactic acid; the weight of evidence is decidedly in favour of free hydrochloric acid.

Food when it is going through the process of digestion is reduced to a pulp by the solvent properties of the gastric juice, which are due to the presence of the animal matter or pepsine, and the hydrochloric acid; neither of these two constituents can digest separately, they must be together; and they must be in that proportion as we have before us in the preceding table; to act as complete disintegrators and solvents.

The general effect of digestion is the conversion of the food into what is called chyme; and though the various materials of a meal are entirely dissimilar in their composition, whether they are azotised or nitrogenous, and non-azotised or non-nitrogenous; when they are once reduced to this condition, viz., chyme, they hardly admit of recognition.

The reader may naturally suppose “that the readiness with which the gastric fluid acts on the several articles of food, is in some measure determined by the state of division, and the tenderness and moisture of the substance presented to it,” and he may also be aware of the fact, that the readiness with which any substance is acted upon by the gastric juice, does not necessarily imply that it possesses nutritive characteristics, for it stands to reason that a substance may be nutritious, and yet hard to digest; and when this is the case, the gastric follicles supply a greater quantity of fluid, in order to effect the conversion of the food into chyme. Pepsine and the hydrochloric acid, the two indispensable and inseparable solvents, are consequently secreted in greater abundance in order to meet and overcome the difficulty, so that the food may be in a condition fit for assimilation with the various tissues.

Man requires a mixed kind of aliment, therefore he must have animal as well as vegetable food, though there are many instances of people who live wholly on animal or vegetable substances; these of course are anomalies, and therefore their habits are unnatural. Vegetarianism is a foolish freak of the weak-minded and semi-ignorant; the structure of the teeth of man points conclusively to the fact that he is both carnivorous and herbivorous; though these vegetable philosophers would have us believe that he is destined to feed upon cabbages!

Food is divided into two groups, nitrogenous and non-nitrogenous, or animal and vegetable; the only non-nitrogenous organic substances of the animal, or nitrogenous, are furnished by the fat, and in some few cases by those vegetable matters that may happen to be in the organs of digestion of those animals who are eaten whole.

Nutritive or plastic, is given to those principles of food which are converted into fibrine or albumen of blood, and being assimilated by the various tissues through its medium, and those principles comprising the major part of the non-nitrogenous food, in the form of fat, gum, starch, and sugar, and other substances of a similar nature, are supposed to be utilised in the production of heat, and are termed calorifaciant, or sometimes respiratory food. The principal ordinary articles of vegetable food contain identical substances, in composition, with the fibrine, caseine, and albumen, which constitute the chief nutritive materials of animal food; for instance, the gluten which is present in corn is identical in composition with fibrine, and is therefore called vegetable fibrine; legumen, which exists in beans, peas, and other seeds of the leguminosæ, is similar to the caseine of milk; and albumen is most abundant in the seeds and juices of nearly all vegetables.

On carefully analysing the preceding remarks on food and some of its uses after it has been digested, and the composition and properties of the gastric juice, it is obvious that salt is not only a simple adjunct to food, and therefore not of much importance, but is an article of diet in every sense of the word, and as necessary, if not more so, than many aliments which are regarded as essential.

In its relations to animal or nitrogenous, and vegetable or non-nitrogenous, food, salt is in every respect important.

The hydrochloric acid of the gastric juice, which is so bountifully secreted by the glands of the stomach, of course drains the whole system of its salt, and especially does it draw the chloride of sodium from the blood, which contains 3·6 in 1000, being held in solution by the liquor-sanguinis.

Animal or nitrogenous food contains only a minimum of salt, which chiefly exists in the muscular tissue, its principal constituents being albumen and fibrine; if, therefore, it is eaten as a rule without salt, digestion is by no means facilitated, because meat being comparatively tough, the glands have to secrete an increased quantity in order to break down or disintegrate it, and there is, as I have observed, a greater drain on the system.

Vegetable or non-nitrogenous food contains potash; only those vegetables growing near the sea contain soda. The same reasons which apply to animal food hold good as regards vegetable, with this difference: the gluten, the legumen, and their other ingredients are acted upon by the gastric juice more rapidly, and that being the case, a less amount is required, and as a natural consequence less salt, or rather chloride of sodium, is abstracted from the blood; because the more the stomach is called upon to exert itself, a greater flow of blood to that viscus is the result, which takes place only when the food to be acted upon is of a harder or tougher material than ordinary, when the organ is filled to repletion, or when salt is omitted as a rule.

Another fact should be borne in mind: cellulose is a substance invariably present in the vegetable kingdom, and is found both in low and high plants; it is present in the fungus as well as in the palm, in the lichen as well as in the oak; it is not subject to climatic influences nor to atmospheric changes, so that its quantity in all plants is always the same. This cellulose is almost identical in its composition with starch, which is a substance entirely non-nutritious. When in the system starch undergoes a transformation, by some process not as yet clearly defined, into sugar; whether in the stomach or by some action of the liver, physiologists are uncertain, but it is an unexplained physiological fact, nevertheless. Sugar, we know, is a very active agent in the production of fat; therefore it is not desirable for us to have an overplus, but rather to keep it under. Salt is not a fat-producer; it has an opposite effect; therefore it should be used plentifully with vegetable food in order to neutralise the effect of the starch or cellulose.