About thirty years ago, as I have already remarked, one of the most distinguished practical geologists of this or any other country directed his attention to a subject of much greater difficulty than the classification of rocks, and their subdivision into primary, secondary, volcanic, and transition. His object was to discover the origin or cause of those fatal diseases which, under the names of fever, dysentery, plague, rheumatism, &c., render the position of man on the globe so precarious, his life at times so brief, valueless to himself or to others, his prospects so gloomy; in brief, by tracing to its origin, if possible, the active agent of such woes to man, to destroy its fatal influence by practical hygienic measures. In a word, Dr. Macculloch hoped, by discovering the cause, to devise the means either of effectually destroying malaria—using the term, however, in a sense at that time peculiar to himself—or so to mitigate its effects as to render it less destructive to mankind. He, an acute and original observer, statistician, and scientific man, properly so called, did not require to be instructed as to the lamentable results which the premature death of millions causes to the surviving relatives—results so eloquently and so correctly depicted by the illustrious Quetelet in his work on Man.4 Of all this he was well aware, and a consciousness of such a condition of humanity, and a firm belief in the opinion that the cause lay in some defect in our social system, remediable by human means, led to those inquiries on which the late Dr. Macculloch based his theory of a universal malaria the cause of most diseases—a theory now adopted in its entirety by a large section of the medical faculty, and by the English Government of the present date.
The theory or theories of Macculloch,5 as expounded by himself, amounted in fact to this—that a poison, which may be called malaria, is generated by vegetable and animal substances whilst undergoing decomposition or putrefaction, and that to the presence of this poison may be traced most of the diseases afflicting civilized man. In a neglected drain or sewer he saw the cause of typhus, of agues, of skin disease, neuralgias, &c.
These views of Macculloch respecting the origin of malaria and its effects on man, were, when first published, and indeed for many years afterwards, looked on with suspicion by the physicians of that day; they were viewed, in truth, as wildly speculative, and wholly unsupported by facts. This opinion still prevails with many, but they are being rapidly borne down by a host of writers—many, it must not be overlooked, enjoying lucrative official appointments, and who thus have a deep and touching interest in supporting and maintaining the theories of Macculloch. An opportunity will occur in the course of this work of tracing briefly the progress of the mania—for such, to a certain extent, it speedily became—and of assigning the merit or demerit of the movement to those to whom it may be due. Here it is only necessary to allude to it as being in fact the source of all those visionary and Utopian schemes for the entire renovation of the social state of man, alternately advocated or deprecated by a press naturally chiming in with the prevailing public feeling. At times the discussion acquires an almost feverish character—as when, for example, during the present summer, “the river” exhaled an odour more than usually unpleasant; at times it cools down in the presence of a proposal to expend many millions of the public money on some wild, untried scheme, under the superintendence of the very men who deliberately, and despite many warnings, reduced “the river” to its present sad condition—of men who had not the candour or the honesty to admit that, proceeding on the conjectures of Macculloch, they hazarded one of the coarsest experiments ever devised on the health of millions.6 These were the men whose course of action the Registrar-General endeavoured to palliate, on the plausible ground that, although they poisoned the river, the doing so was much less injurious to the inhabitants of London than to suffer the cesspools to continue any longer buried in the earth, although for the most part hermetically sealed! Thus were they permitted in open day to pollute the surface-drains of the metropolis, converting them into sewers—to render the streets and squares impassable—and finally to convert the river itself into a kind of elongated cesspool! This, says the Registrar-General, is an evil of less magnitude than the permitting the cesspools and dead-wells to remain as they were until gradually and cautiously disposed of by other means.
It were easy to show, were it worth while—1st. How the persons to whom I here allude suffered to be withdrawn from the Thames nearly a half of its natural waters before reaching London; 2nd. How next they converted the healthy surface drains of London and of its environs into odious sewers, ignoring the distinction between drain and sewer, a distinction which the most ignorant of day labourers perfectly understands, and heretofore had uniformly respected; 3rd. How they refused to suffer the suicidal act to proceed gradually and slowly, whereby the river, out of its own natural resources, might and would in time have accomplished its own depuration, but as best suiting their ultimate views, issued compulsory edicts on the inhabitants of this great city to empty into the river, and almost at once, the accumulated excreta of a quarter of a century, such being at least the average age of the contents of the cesspools. Thus was demanded of the river a depurative force at the least twenty times greater than under another system would have been required of it. Lastly, to complete a series of experiments so injurious to the public, but so profitable to individuals, the same party proposes further to deprive the stream of all aid in the purification of its waters, by pouring into the German Ocean the entirety of the water which the natural drainage of London, and the valley in which it stands, contribute to it, together with one-half the waters of the river itself, taken from it above the tide-way for the supply of the capital.
Thus, by a series of man?uvres, transparent enough to those who have carefully watched the movements for the last twenty years, its inhabitants are now called on at their own expense to remedy the clumsy experiments of those who occupy positions they could not fill in any country but England.7
Four-and-twenty centuries ago, Hippocrates, the father of medicine, gave to the world his celebrated treatise, de aere, aquis et locis (Περι ?δατων αερον κα? τοπων), having for its object an inquiry into the influence of the external world on man’s physical structure and moral nature. To trace the origin of disease to these circumstances, does not seem to have fallen within the scope of his argument; accordingly, it can scarcely be said that any author prior to Macculloch ever considered this matter from a philosophical or physiological point of view, a reason for which may be found, I think, in the absence of a minutely accurate chemical analysis of natural and artificial products. No Ehrenberg had taught mankind the wonders of the living microscopic world of life; even the geology of Macculloch was much behind the profound analyses of the present day. Sober thinking men had rejected the bold speculations of Buffon as to the antiquity of life on the globe, and the demonstrations of the immortal Cuvier were as yet but partially admitted; whilst the theories of Lamark, respecting the vast influence of life in the construction of the crust of the globe, had been suffered quietly to fall into abeyance. Life was thought to be but a recent acquisition by the earth; the Silurian and Cambrian systems of fossils were either unknown or misunderstood. These fossils, at present called “the first stages of this grand and long series of former accumulations,” must, in the nature of things, yield their claims to others which geology will no doubt soon discover, thus rendering more than probable the theory that life and the globe are coeval.
Placed accidentally in a country usually considered as a focus or centre of that malaria or influence, whatever it may be, which man, correctly, perhaps, esteems as the source and cause of remittent and intermittent fevers, I have thought it might prove a labour of some utility to mankind to test the theoretical opinions to which I have alluded, by an appeal to facts submitted to more refined analyses than were known at the period of their promulgation. Time can only show in how far the views I venture to substitute for those now in vogue fairly represent the truth. A power of nature, invisible and impalpable, harasses mankind, destroys armies,8 desolates districts and countries, slays adult man at the moment when his native land expects from him a suitable return for all the labour, trouble, and expense bestowed on him: to inquire into the nature of this poison is the object, or at least the main object, of this work. If we would rightly understand its essence and properties, it may be admitted that we ought to study carefully in the first instance its manifestations and effects; now these are tolerably well known. The most difficult part of the inquiry remains, that is, the demonstration of the essential nature of the poison or miasm giving rise to such disastrous results. All modern science leads to the conclusion that malaria, whether it originate in circumstances over which man has no control, despite every hygienic effort, or emanate from a combination of circumstances mainly caused by man himself, or be only effectual when it meets with individuals living in contempt of common sanitary precautions, must, by its material nature, be within the range of philosophical research. To Schonbein, a distinguished chemist now alive, we owe the discovery of ozone. Major Tulloch had already hinted at the doctrine that the cause of the frightful mortality in tropical countries was to be looked for in electrical conditions of the atmosphere, of whose nature we as yet are ignorant.9 Other discoveries in this direction are sure to follow at no distant period. What so obscure a short time ago as electricity? Now look at its position, at least, as a science of application! Life, it is true, is the mystery of mysteries, equally so in its origin and extinction; yet granting this to be a truth, and foreseeing in it all the difficulties of every inquiry directed to elucidate its essential nature, every reflecting mind must be struck with the remarkable discoveries of modern times, all tending to show the close alliance between the chemical and vital phenomena, an alliance wholly unknown to the most gifted of antiquity. The modern world, right or wrong, looks to chemistry for the solution of many great and important problems, the most elevated of which unquestionably is the discovery of the causes rendering certain wide-spread localities of this earth unfit for the habitation of those at least who may not claim them as their natal soil; of which they are not the aborigines.