CONCLUSION.
In the first chapters of this work I have endeavoured to trace briefly yet succinctly the history of opinion as to the nature of malaria, showing how, prior to the appearance of Macculloch, no one had given to the theory of malaria any definite form. In those which followed I have traced the history of his presumed discovery from the period of its first announcement to its distinct refutation by one of the ablest of statisticians, showing that, notwithstanding this refutation, the physician having, in fact, no other theory to fall back on, persisted in adopting the theory, and, as a natural result, continued to look for and to find in cesspools and ditches, lay-stalls and drains, that unknown and mysterious poison which they had been told by Macculloch was the cause of all diseases. Confounding it with bad odours of all sorts, they sought for remedies in the destruction of bad odours; at times they sealed the sewers and cesspools hermetically and by law: now they opened up and ventilated the sewers and cesspools also by law;[72] and lastly, on finding that they had poisoned the air of the metropolis, and that every experiment they made ended in the precisely opposite results to what they had foretold would happen, as a last resource they endeavour now so to dilute the refuse of living beings as to render it, if possible, inodorous at least. This experiment will also fail. Like true Englishmen, they would not let well alone; they would attempt to solve questions by main force, which science, aided by long and careful experience and observation, could alone effect. At last Liebig appeared, and gave to the whole question a new phasis and another basis; that basis rests on an appeal to the great laws of nature, and not on any researches into the occult, hidden, and mysterious laws regulating the building up and the constructing of the various forms of animal and vegetable life. In this grand work the vital force is in action, whereas the destructive processes by which she annihilates her own forms are strictly chemical; there science may be properly said to commence in respect of the great question I now consider; and uniting experience with observation, it seems to lead to the following conclusions, which, if legitimate, will probably stand their ground until overthrown or modified by the larger experience of succeeding ages.
§ 1. Seeing that putrescent, that is fermentable, bodies can and do exert so great an influence on organic compounds when dead (in the sense we consider them), it is not unreasonable to suppose that animal structures and fluids capable of being fermented, may undergo the same process, that is, fermentation, putrescence, and destruction, or decay, whilst forming a part of the living body.
§ 2. As no sane person doubts the harmony which can be shown to exist in all created beings, so it is probable, if not quite certain, that the laws of decomposition must be as regular as the laws of composition; or, in other words, that as the organic matter is without a doubt the same throughout the living world, and as living bodies are built up or constructed agreeably to certain laws, so, undoubtedly, will they be decomposed by laws equally fixed and constant; invariable; and the nature of the material so decomposed will in no shape be affected by those specific differences which bestow on organic nature her beauteous and varied aspect.
§ 3. The final product, whether of composition or decomposition, must be the same in all respectively; the infusoria, as well as the gigantic whale and elephant, are composed, when living, of the same elementary tissues, and, when dead, decompose into elements the same in all.
§ 4. The presence of microscopic animalcules in putrifying substances is viewed by Liebig as accidental, and not essential to putrefaction or to fermentation; but even admitting this, it is certain that animalcules (infusoria) exist everywhere in inconceivable numbers; if water contains these putrescible substances, as it must always do, then the infusoria are also present in the water; let this water evaporate under the heat of the sun, and we have in a fermentable, that is, putrescible, condition countless myriads of infusoria wafted through the atmosphere, and in certain localities (Pontine Marshes, Sierra Leone, the Orinoco, &c.) forming almost a constant, if not a constituent, part of the atmosphere; they pass into living bodies by respiration: hence the hitherto inexplicable phenomena with regard to the influence of locality in the production of disease, whether derived from animal or vegetable remains.
§ 5. Thus these bodies cause disease, not as live matter, but as dead, fermentable, and putrescible. They are not found everywhere, nor are they everywhere liable to pass into fermentation, a certain degree of heat being necessary for the production of this condition. Their evil effects on human life are chiefly felt when man places himself in a false position in regard to them. In pursuit of gain, national or individual, he seeks the deltas of the rivers of hot climates, plunges within the tropics, despising the maxims of the natives of those countries, encamps on or near putrescent marshes, hoping to escape destruction; prances in holiday costume across the Dobrudscha, as if he were on the Champs Elysées or the grassy slopes of Hyde Park, and having carried folly and contempt for the experience of others to its height, pays the sad penalty sure to be exacted by nature from all those who despise her warnings.
These are my opinions, supported, I believe, by facts and figures, and to those who honour me with a perusal of the preceding chapters I beg leave to say, in the words of the ancient poet and satirist—
Si quid novisti rectius istis,
Candidus imperti, si non—his utere mecum.