Imágenes de páginas
PDF
EPUB

of blood to the stomach the sensa- themselves in tubs of salt water, he tion of uneasiness is carried

away. says.

This would undoubtedly reHence we may conclude that Hunger lieve their thirst, but it is a plan is in some way dependent on the state which would be excessively dangerof the circulation in the stomach. ous in shipwrecks, unless food were

abundant, since the abstraction of so Thirst closely resembles Hunger much heat as would follow a bath in being a general or Systemic sensa would in all probability be fatal. tion, although it is usually considered As deficiency of food to supply the only as a local and Organic sensation waste of tissue is the primary cause ---the dryness of the mouth and of Hunger, so deficiency of water to throat. This dryness of the throat supply the waste which goes on inand mouth, so familiar to us all, is cessantly in the excretions, respiraproduced by a deficiency of liquid in tion, and perspiration, is the primary the body ; but it may be, and often cause of "Thirst. Every time we is, produced when there is no defi- breathe we throw from our lungs a ciency in the general system, nothing quantity of water in the form of but a local disturbance, this disturb- vapour; and we are made sensible of ance producing a local sensation. this when the breath condenses on Wines, coffee, spices, &c., create a the colder surface of glass or steel, strong feeling of thirst, yet the two and when, as in winter, the atmosfirst increase the quantity of liquid phere is sufficiently cold to condense instead of diminishing it. And we the vapour on its issuing from our know how ineffectual liquid in any mouths. This is only one source of quantity is to quench the feeling of the waste of water : a more imporThirst under some conditions, espe- tant source is that of perspiration, cially after long suffering.

which in hot weather, or during Andersson, in his travels in Africa, violent exercise, causes the water to describes the sufferings of his men roll down our_skins with obtrusive and cattle, adding, “even when the copiousness. But even when we are thirsty, men and animals were let perfectly quiescent, the loss of water, loose in the water, although they although not obvious, is considerable. drank to repletion, the water seemed It is calculated that there are no less to have lost its property, for our best than twenty-eight miles of tubing on endeavours to slake our thirst proved the surface of the human body, from unavailing."* The long continuance which the water will escape as insenof Thirst had produced a certain sible perspiration ; and although the feverish condition which could not amount of water which is thus evabe immediately relieved when the porated from the surface must necessystem received its necessary supply sarily vary with the clothing, the of liquid ; this shows that although de- activity, and even the peculiar conficiency of liquid is the primary cause stitution of the individual, an average of Thirst, the proximate cause must estimate has been reached which be some local affection which has shows that from two to three pounds been induced.

of water are daily evaporated from On the other hand, this local sen the skin. From the lungs it is ascersation is so dependent on the system, tained that every minute we throw that if water be injected into the veins off from four to seven grains of water, or the intestines, Thirst disappears, from the skin eleven grains. To although the mouth and throat have these must be added the quantity ahnot been touched. A humid atmos- stracted by the kidneys, a variable phere prevents Thirst ; a bath re but important element in the sum. lieves it, because the water is ab It may not at first be clear to the sorbed through the skin. On this reader why an abstraction of water principle, Franklin grounds his ad- daily should profoundly affect the vice to men who are exposed to organism unless an equivalent be rescarcity of drink : they should bathe stored. What can it matter that the

ANDERSSON : Lake Ngami, p. 38.

body should lose a little water as when he had a refractory horse, alvapour? Is water an essential part ways used thirst as the most effective of the body? Is it indispensable to power of coercion, giving a little life? Not only is water an essential water as the reward for every act of part of the body, it might be called obedience. The histories of shipthe most essential, if pre-eminence wreck paint fearful pictures of the could be given where all are indis- sufferings endured from thirst ; and pensable. In quantity, water has an one of the most appalling cases enormous preponderance over all known is the celebrated imprisonother constituents : it forms 70 per ment of one hundred and forty-six cent of the whole weight! There is men in the Black Hole at Calcutta not a single tissue in the body-not -a case frequently alluded to, but even that of bone, not even the which must be cited here at some enamel of the teeth-into the com- length on account of its physiological position of which water does not bearing : enter as a necessary ingredient. In The Governor of Fort-William at some of the tissues, and those the Calcutta, having imprisoned a mermost active, it forms the chief ingre- chant-the well-known Omychund, dient. In the nervous tissue 800 -the infamous Nabob of Bengal, parts out of every 1000 are of water; Surajah Dowlah, on the look - out in the lungs 830; in the pancreas for a pretext, marched against 871; in the retina no less than 927. Fort - William with a considerable Commensurate with this anatomical force, besieged and took it, and impreponderance, is the physiological prisoned the surviving part of the importance of water. It is the car- garrison in the barrack-room named rier of the food, the vehicle of waste. the Black Hole. The letter in which It holds gases in solution, dissolves Mr Holwell, the officer in command, solids, gives every tissue its physical describes the horrors of this imprisoncharacter, and is the indispensable ment is printed in the Annual Recondition of that ceaseless change gister for 1758, and from it the folof composition and decomposition on lowing extracts are made :-which the continuance of life depends. Such being the part played by hundred and forty-six wretches, exhaust

“ Figure to yourself the situation of a water in the organism, we can under- ed by continual fatigue and exhaustion, stand how the oscillations of so im- crammed together in a cube of eighteen portant a fluid must necessarily bring feet, in a close sultry night in Bengal, with it oscillations in our feelings of shut up to the eastward and southward comfort and discomfort, and how any (the only quarters whence air could reach unusual abstraction of it must produce us) by dead walls, and by a wall and that disturbance of the general sys

door to the north, open only to the westtem which is known under the name

ward by two windows strongly barred of Raging Thirst--a disturbance far

with iron, from which we could receive

scarce any the least circulation of fresh more terrible than that of starvation,

air.

We had been but a few and for this reason: During

absti

minutes confined before every one fell nence from food, the organism can into a perspiration so profuse, you can still live upon its own substance, form no idea of it. This brought on a which furnishes all the necessary raging thirst, which increased in propormaterial ; but during abstinence from tion as the body was drained of its moisliquid, the organism has no such ture. Various expedients were thought source of supply within itself. Men of to give more room and air. To gain have been known to endure absolute the former it was moved to put off their privation of food for some weeks, clothes; this was approved as a happy but three days of absolute privation motion, and in a few

moments every one of drink (unless in a moist atmos

was stripped-myself, Mr Court, and the

two young gentlemen by me, excepted. phere) is perhaps the limit of endurance. Thirst is the most atrocious selves with having gained a mighty ad

For a little while they flattered themtorture ever invented by Oriental vantage ; every hat was put in motion to tyrants. It is that which most gain a circulation of air, and Mr Baillie effectually tames animals. Mr Astley, proposed that every man should sit down

on his hams. This expedient was seve lent struggles and frequent contests to ral times put in practice, and at each get it, that before it reached the lips of time many of the poor creatures, whose any one, there would be scarcely a small natural strength was less than that of tea-cupful left in them. These supothers, or who had been more exhausted, plies, like sprinkling water on fire, only and could not immediately recover their seemed to feed the flame. Oh! my dear legs when the word was given to rise— sir, how shall I give you a just conception fell to rise no more, for they were in of what I felt at the cries and cravings of stantly trod to death or suffocated. those in the remoter parts of the prison, When the whole body sat down, they who could not entertain a probable hope were so closely wedged together that of obtaining a drop, yet could not divest they were obliged to use many efforts themselves of expectation, however unbefore they could get up again. Before availing, calling on me by the tender connine o'clock every man's thirst grew siderations of affection and friendship. intolerable, and respiration difficult. The confusion now became general and Efforts were made to force the door, but horrid. Several quitted the

other winin vain. Many insults were used to the dow (the only chance they had for life) guard to provoke them to fire on us. to force their way to the water, and the For my own part, I hitherto felt little throng and press upon the window was pain or uneasiness, but what resulted beyond bearing ; many, forcing their way froin my anxiety for the sufferings of from the further part of the room, pressed those within, By keeping my face close down those in their passage who had less between two of the bars I obtained air strength, and trampled them to death. enough to give my lungs easy play, From about nine to eleven I sustained though my perspiration was excessive, this cruel scene, still supplying them with and thirst commencing. At this period water, though my legs were almost broke so strong a urinous volatile effluvia came with the weight against them. By this from the prison that I was not able to time I myself was near pressed to death, turn my head that way for more than a and my two companions, with Mr Parker, few seconds at a time.

who had forced himself to the window, “Now everybody, except those situ were really so. At last I became so ated in and near the windows, began to pressed and wedged up, I was deprived grow outrageous, and many delirious. of all motion. Determined now to give Water! water! became the general cry. everything up, I called to them, and An old Jemmantdaar, taking pity on us, begged them, as a last instance of their ordered the people to bring us some regard, that they would relieve the presskins of water. This was what I dreaded. sure upon me, and permit me to retire I foresaw it would prove the ruin of the out of the window to die in quiet. They small chance left us, and essayed many gave way, and with much difficulty I times to speak to him privately to forbid forced a passage into the centre of the it being brought ; but the clamour was prison, where the throng was less by the so loud, it became impossible. The many dead, amounting to one third, and water appeared. Words cannot paint the numbers who flocked to the windows; the universal agitation and raving the for by this time they had water also at sight of it threw us into. I flattered the other window. myself that some, by preserving an equal self down on some of the dead, and, re. temper of mind, might outlive the night; commending myself to Heaven, had the but now the reflection which gave me comfort of thinking my sufferings could the greatest pain was, that I saw po pos. have no long duration. My thirst now sibility of one escaping to tell the dis grew insupportable, and the difficulty of mal tale. Until the water came I had not breathing much increased ; and I had myself suffered much from thirst, which not remained in this situation ten min. instantly grew excessive.

We had no utes before I was seized with a pain in means of conveying it into the prison my breast, and palpitation of heart, both but by hats forced through the bars ; to the most exquisite degree. These and thus myself, and Coles, and Scott obliged me to get up again, but still the supplied them as fast as possible. But pain, palpitation, and difficulty of breaththose who have experienced intense thirst, ing increased. I retained my senses notor are acquainted with the cause and na withstanding, and had the grief to see ture of this appetite, will be sufficiently death not so near me as I had hoped, but sensible it could receive no more than a could no longer bear the pains I suffered momentary alleviation : the cause still without attempting a relief, which I subsisted. Though we brought full hats knew fresh air would and could only give through the bars, there ensued such vio me. I instantly determined to push for

I laid my

the window opposite to me, and by an the first ranks ; and got hold of the bars, effort of double the strength I ever be from which there was no removing them. fore possessed, gained the third rank at Many to the right and left sunk with the it-with one hand seized a bar, and by violent pressure, and were soon suffocatthat means gained a second, though i ed; for now a steam arose from the think there were at least six or seven living and the dead, which affected us in ranks between me and the window. In all its circumstances, as if we were fora few moments the pain, palpitation, and cibly held by our heads over a bowl of dijaculty of breathing ceased, but the strong volatile spirit of hartshorn until thirst continued intolerable. I called suffocated; nor could the effluvia of the aloud' Water for God's sake.' I had been one be distinguished from the other. I concluded dead; but as soon as the men need not ask your commiseration when found me amongst them, they still had I tell you that in this plight, from half the respect and tenderness for me to cry an hour after eleven till two in the out, 'Give him water ' nor would one of morning, I sustained the weight of a them at the window attempt to touch it heavy man with his knees on my back, till I had drunk. But from the water I and the pressure of his whole body on kad no relief; my thirst was rather in my head ; a Dutch sergeant who had creased by it; so I determined to drink taken his seat on my left shoulder, and a no more, but patiently wait the event. I black soldier bearing on my right: all kept my mouth moist from time to time by which nothing would have enabled me sucking the perspiration out of my shirt to support but the props and pressure sleeves, and catching the drops as they fell equally sustaining me all round. The two like heavy rain from my head and face; you latter I frequently dislodged by shifting can hardly imagine how unhappy I was if my hold on the bars, and driving my any of them escaped my mouth.

knuckles into their ribs; but my friend I was observed bg one of my companions above stuck fast, and, as he held by two on the right in the expedient of állaying bars, was immovable. The repeated my thirst by sucking my shirt-sleeve. trials I made to dislodge this insufferable He took the hint, and robbed me from encumbrance upon me, at last quite extime to time of a considerable part of bausted me, and towards two o'clock, my store ; though, after I detected him, finding I must quit the window or sink I had the address to begin on that sleeve where I was, I resolved on the former, first when I thought my reservoirs were having borne truly, for the sake of others, sufficiently replenished, and our mouths infinitely more for life than the best of and noses often met in contact. This it is worth. man was one of the few who escaped I was at this time sensible of no death, and he has since paid me the com pain and little uneasiness. I found a pliment of assuring me he believed he stupor coming on apace, and laid myself owed his life to the many comfortable down by that gallant old man, the redraughts he had from my sleeves. No verend Jervas Bellamy, who lay dead Bristol water could be more soft or plea- with his son, the lieutenant, hand in sant than what arose from perspiration. hand, near the southernmost wall of the

“By half-past eleven the much greater prison. Of what passed in the interval, number of those living were in an out to the time of my resurrection from this rageous delirium, and others quite ungo

hole of horrors, I can give you no acvernable; few retaining any calmness count." but the ranks near the windows. They now all found that water, instead of re.

At six in the morning the door lieving their uneasiness, rather heighten was opened, when only three-anded it, and Air / air ! was the general cry. twenty out of the hundred and fortyEvery insult that could be devised against six still breathed. These were subthe guard was repeated to provoke sequently revived. Although the them to fire on us, every man that could, principal cause of this mortality rushing tumultuously towards the win must be ascribed to the vitiated atdows with eager hopes of meeting the mosphere rather than to Thirst, we first shot. But these failing, they whose nevertheless see some of the frightful strength and spirits were quite exhaust phenomena of Thirst exemplified in ed laid themselves down, and quietly this narrative. Death by asphyxia expired upon their fellows; others who had yet some strength and vigour left, (from vitiated air) is generally peacemade a last effort for the windows, and ful, and not at all such as is describseveral succeeded by leaping and scram ed in the foregoing. Attention is bling over the backs and heads of those in moreover called to certain passages

a

in italics. These show that the sen water moistened mouth and throat on sation of Thirst is not merely a its way to the stomach, thirst was Systemic sensation dependent on not appeased because the water was deficiency of liquid in the system, but not absorbed. The dog drank till a specific sensation dependent on a fatigue forced it to pause, and a few local disturbance : the more water minutes afterwards recommenced the these men drank, the more dreadful same hopeless toil; but no sooner seemed their thirst; and the mere was the opening closed, and the water sight of water rendered the sensation, retained in the stomach, from whence which before was endurable, quite in- it was absorbed into the system, than tolerable. The increase of the sensa thirst quickly vanished.* tion following a supply of water, would After learning the physiological be wholly inexplicable to those who importance of water, and remembermaintain that the proximate cause of ing how the water is continually beThirst is deficiency of liquid ; but is ing removed from the body in respinot wholly inexplicable, if we regard ration, perspiration, and the various the deficiency as the primary, not the excretions, we are greatly puzzled by proximate cause ; for this primary the great variations which animals cause having set up a feverish condi- exhibit in the quantity they drink. tion in the mouth and throat, that The difficulty is not explained by a condition will continue after the ori- reference to the food of the animals, ginal cause has ceased to exist. The some vegetable feeders requiring stimulus of cold water is only a mo- large quantities of water, while others mentary relief in this case, and exag- subsist for months without drinking, gerates the sensation by stimulating the supply they receive in the vegea greater flow of blood to the parts. tables they eat being sufficient for If, instead of cold water, a little luke- their wants. Dr Livingstone found warm tea, or milk-and-water had the elands on the Kalahari Desert, been drunk, permanent relief would although in places where water was have been attained; or if instead of perfectly inaccessible, with every incold water a lump of ice had been dication of being in splendid contaken into the mouth, and allowed to dition, and their stomachs actually melt there, the effect would have been contained considerable quantities of very different-a transitory applica- water. “I examined carefully the tion of cold increasing the flow of whole alimentary canal,” he says, “in blood, a continuous application driv- order to see if there were any pecuing it away. If, therefore, the reader liarity which might account for the is ever suffering from intense thirst, fact that these animals can subsist let him remember that warm drinks for months together without drinkare better than cold drinks, ice is ing, but found nothing. Other anibetter than water.

mals, such as the düiker (Cephalopus We must not, however, forget that mergens), the steinbuck (Tragulus although, where a deficiency of liquid rupestris), the gemsbuck (Oryx cahas occasioned a feverish condition pensis), and the porcupine, are all of the mouth and throat, no supply able to subsist for many months at a of cold liquid will at once remove time by living on bulbs and tubers that condition, the relief of the Sys- containing moisture. Some animals, temic sensation not immediately pro on the other hand, are never seen ducing relief of the special sensation, but in the vicinity of water. The nevertheless, so long as the system is presence of the rhinoceros, buffalo, in need of liquid, the feeling of thirst and gnu, of the giraffe, zebra, and must continue. "Claude Bernard ob- pallah (Antelope melampus), is always served that a dog which had an à certain indication of water being opening in its stomach drank unceas within seven or eight miles.”+ The ingly, because the water ran out as only solution of the difficulty which fast as it was swallowed; in vain the presents itself to my mind is, that

* Claude BERNARD : Leçons de Physiol. Expérimentale, ii. 51.
Missionary Travels in South Africa, p. 56.

« AnteriorContinuar »