As there is a continual waste and decay, however, both of our fluids and solids, some degree of reparation is absolutely necessary, especially to animals of warm blood; and such ingesta as would give the stimulus of food, without being possessed of any nutritious principle, would indeed continue life for a certain time; but disease would ensue. The provision used at sea answers, in a great measure, to this description; for unless the powers of digestion and assimilation are remarkably strong, salt beef and biscuit, which have been long kept, do not contain much more nourishment than saw-dust, or the bark of a tree, and the disease induced by this diet is the scurvy.
The nature and symptoms of the scurvy countenance this opinion: for as the means of renewing the animal matter of our bodies is withdrawn under this course of diet, nature, in consequence of an accommodating principle, observes a sort of frugality, and the animal œconomy adopts such measures as may be productive of the least possible waste and corruption of the fluids. Accordingly all the secretions become scanty; and, in particular, one of the first symptoms of this disease is a suppression of perspiration, as appears by the goose-skin that attends it. There is a paucity of urine. There is also a great languor in the circulation, which may be considered either as a means adopted by nature to prevent that vitiated and effete state of the fluids which a brisker action might induce; or it may happen from a want of that due supply of nourishment necessary to produce a vigorous action of all the functions.
We have a proof of this general languor not only from the great aversion to motion, and the great disposition to syncope, but from the inspection of the dead body, from which it appears that the whole circulating system, being more flaccid and less elastic, is subject to preternatural distention. The heart is accordingly found enlarged in bulk, the size of the cavities being increased; and in the extremities, where the circulation is naturally most languid, the small vessels carrying the colourless part of the blood, are so far enlarged as to admit the red part of it, as appears by the livid colour; and where this is the case, these vessels being unable to carry on the circulation, a stagnation ensues, as is evident in those livid appearances most common about the calves of the leg, which feel like a hard cake. I have examined those parts in the dead subject, and found a want of fluidity in the contents of the vessels, but could not discover any thing like eechymosis; from which I concluded that the colour was owing to an error loci, and the hardness to stagnation and coagulation of the fluids, and a want of action of the vessels.
The incurable state of ulcers, so common in this disease, is also what we might expect from the defect of fresh assimilated juices; for where a breach is made, either by nature or accident, in the solids, particularly of the extremities, the proper suppuration is prevented by the depraved state both of the fluids and vessels; and we cannot expect that renewal of solid parts in which healing consists, where both the instruments and materials of its formation are so defective.
I shall conclude what I have to say on this subject, by shortly considering whether or not this disease is ever contagious.
There is something in the nature and history of the scurvy that would lead us at once to pronounce that it is not infectious; for the external causes on which it depends are so obvious, and seem so adequate to account for its appearance and prevalence upon certain occasions, as at first sight to exclude every other external cause.
But it seems extremely unphilosophical to deny the reality or possibility of any thing in Nature, from our supposed knowledge of the means and causes she employs, particularly in a branch of science so obscure as the animal œconomy. Could we, therefore, prove the point as a matter of fact, it would be in vain to deny it, from our fancied acquaintance with Nature’s modes of operation.
The facts which give a suspicion of the scurvy being infectious are, 1st, What is related by Dr. Lind, that the sea scurvy spread at one time from the naval hospital to the people of the adjacent country. 2dly, There occurred several instances, in the first part of this work, of this disease prevailing to a much greater degree in some[123] particular ships than others, though upon the most accurate inquiry there was found no difference in the diet, or any other external or predisposing cause adequate to account for this. We can conceive, that those ships having accidentally a few men, whose constitutions were remarkably predisposed to this disease, might catch it earlier than in other ships, and communicate it to the rest of the crew.
The only practical inference that would lie from the establishment of this fact would be, that when the disease begins first to appear, the men affected should be separated from the rest; and this is a good practice, whether this opinion is true or not; for such men ought to be put in one mess, in order that they all may live upon the same antiscorbutic articles of diet, and that they may more easily be debarred from the use of their common provisions, of which this disease does not make them lose the relish.