The history of salt

by Evan Marlett Boddy

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.