AN ESSAY 
 
 ON THE 
 
 PRODUCTION AND PROPAGATION 
 
 OF THIS POISON, 
 
 AND ON THE 
 
 NATURE AND LOCALITIES OF THE PLACES 
 
 BY WHICH IT IS PRODUCED ; 
 
 WITH AN 
 
 ENUMERATION OF THE DISEASES CAUSED BY IT, 
 
 AND 
 
 OF THE MEANS OF PREVENTING OR DIMINISHING THEM, BOTH AT 
 
 HOME AND IN THE NAVAL AND MILITARY SERVICE. 
 
 BY JOHN MACCULLOCH, M.D., F.R.S., &c. &c. 
 
 PHYSICIAN IN ORDINARY TO HIS ROYAL HIGHNESS PRINCE 
 LEOPOLD OF SAXE COBOURG. 
 
 PHILADELPHIA : 
 PRINTED AND PUBLISHED BY THOMAS KITE, 64 WALNUT ST. 
 
 MDCCCXXIX. 
 
ADVERTISEMENT. 
 
 The present volume has, in conformity to the advice of better judges 
 than the author, been separated from two subsequent ones containing 
 the history of the diseases, of a remittent and intermittent nature, 
 which are admitted to be the produce, chiefly, of Malaria. Those 
 two volumes, which will shortly appear, will be found to comprise an 
 account, generically, of marsh fever and of Neuralgia ; one volume 
 having been allotted to each : the former including an account of 
 numerous disorders dependent on intermittent or remittent, the cha- 
 racters and treatment of which have been often misapprehended, while 
 the latter, under a new and generic view, connects Neuralgia, in all its 
 forms, with intermittent : treating of various diseases, original or con- 
 sequential, which appertain to this as a generic affection, and pointing 
 out a systematic plan of cure for the whole of a train of disorders, of 
 the most distressing and refractory nature. 
 
 It has necessarily followed, that in the present Essay, or Volume, 
 there is a deficiency of illustration as to the disorders in question, 
 since it is chiefly trusted to the medical ones ; but to have altered 
 this, would have caused repetitions which would have enlarged the 
 bulk, and increased the expense, to at least the medical readers. To 
 them it will therefore be a work of three volumes ; while the present 
 part remains an essay in one, for those who, as travellers, or as resi- 
 dents in unhealthy districts, or from whatever other causes, may pos- 
 sess an interest in a subject of this nature, which they could not be 
 expected to take in a medical treatise, however popular the subject, 
 and however it has been endeavoured to render it intelligible, as well 
 as interesting, to every class of readers. 
 
CONTENTS. 
 
 Chapter I. 
 
 Introductory remarks on the effects of Malaria, and on the utility 
 of a knowledge of that subject. .... 6 
 
 Chapter II. 
 
 Nature of the evidences respecting the production of Malaria 
 in situations of a less notorious or acknowledged character. 12 
 
 Chapter III. 
 
 Of the soils and situations which most commonly produce Ma- 
 laria. . . . . . . . 21 
 
 Chapter IV. 
 
 Of the soils and situations less conspicuously productive of Ma- 
 laria, or as yet unsuspected of it. . . . 28 
 
 Chapter V. 
 
 On certain obscure or disputed cases relating to the production 
 of Malaria. ...... 64 
 
 Chapter VI. 
 
 On revolutions and changes which take place with regard to the 
 production of Malaria, whether from natural causes, or from 
 artificial sanitary measures. . . . .84 
 
1V CONTENTS. 
 
 Chapter VII. 
 On the propagation of Malaria. ... 99 
 
 Chapter VIII. 
 
 On the climates and seasons peculiarly favourable to the produc- 
 tion and propagation, or the effects of Malaria. . . 1 55 
 
 Chapter IX. 
 On the Geography of Malaria. . . . .168 
 
 Chapter X. 
 On the Nature of Malaria. . . . .191 
 
 Chapter XI. 
 
 On the general effects of Malaria upon the constitutions of the 
 inhabitants of marshy districts, and on the diseases which 
 seem to be produced by it. ... \ 95 
 
CHAPTER L 
 
 Introductory remarks on the effects of Malaria, and on the utility 
 of a knowledge of that subject. 
 
 It has long been familiar to physicians that there was produced 
 by wet lands, or by marshes and swamps, a poisonous and aeri- 
 form substance, the cause, not only of ordinary fevers, but of inter- 
 mittents ; and to this unknown agent of disease the term marsh 
 miasma has been applied. Nor is such knowledge confined to 
 physic. Throughout the world it is a fact known to the vulgar, 
 and even to less enlightened nations ; familiar to the negroes of 
 Africa, familiar to the lower orders of France, Italy, Holland, 
 and elsewhere, and not less known to at least our own rural 
 population occupying districts of this character ; since every la- 
 bourer in Lincolnshire or Essex believes that his ague is the pro- 
 duce of his fens, if neither he nor his physician is so well aware, 
 as both ought to be, that his common fever of summer or au- 
 tumn has the same source, and if neither inquire, with sufficient 
 care, where this pernicious land is present, and this poisonous 
 substance generated. 
 
 This is the unseen, and still unknown, poison t© which Italy 
 applies the term that I have borrowed, Malaria. This is the 
 cause of fevers both ordinary and intermitting ; but it is the cause 
 also of other disorders, scarcely less important in point of num- 
 bers and of mortal power. Such are dysentery and cholera ; and 
 yet all these united form but one portion of the enormous mass 
 of disease, of suffering, and of mortality dependent on this 6ingle 
 cause. 
 
 Of this I shall hereafter give the most ample demonstration : 
 since I trust that I shall be able to trace to this great source of 
 evil, a large proportion out of the whole of the chronic disorders 
 which are the causes of such extensive suffering and wide incon- 
 venience ; while it is already known that there are some depen- 
 dent on this cause, which occasionally terminate in lingering 
 and protracted death. Still further, I think that I shall be able 
 to prove it a widely acting cause of ^vaat « -ulled nervous dis- 
 orders ; the most common, p robs My the chief, source of the most 
 painful diseases to which, mankind is subject, of which one at 
 
 B 
 
O MALARIA. 
 
 least is familiar under the term tic douloureux ; and, lastly, the 
 far more frequent source of those innumerable ailings called, in 
 the ordinary language of society, ill health, by which are espe- 
 cially persecuted those who inhabit certain situations in our own 
 country, as in many others. 
 
 How widely Malaria is a cause of death, will be apparent al- 
 most on a moment's consideration, when we recollect, that in 
 all the warmer, and thence more populous, countries, nearly the 
 entire mortality is the produce of fevers, and these fevers the pro- 
 duce of Malaria. I have said'elsewhere, that it has been estimat- 
 ed to produce one-half of the entire mortality of the human race ; 
 nor do I think that this computation, made by physicians of care 
 and consideration, has been exaggerated. If in our own more 
 fortunate climate it is less destructive, it is far more so than is 
 commonly imagined ; since, of those who die from fevers, it may 
 safely be asserted, that more than nine in ten perish from the fe- 
 vers of this class, too generally confounded with the contagious 
 disorder of the same name, under the term Typhus* And if the 
 deaths produced in England by fevers, in this present season 
 alone, 1826, be examined, if I could name a single parish, and 
 that not a peculiarly unwholesome district, where, in a popu- 
 lation of sixteen hundred, the mortality, in two months, was 
 one in thirteen, we have surely abundant reason, if far less than 
 our neighbours of France, Holland, and Italy, to take an interest 
 in the cause of such diseases, had we even no other motive ; and 
 the more particularly if, by an accurate knowledge of the cause, 
 we can avert its power, or diminish its influence, and thus re- 
 duce this heavy account of human suffering, with all its compli- 
 cated consequences* 
 
 But if, from having heard this term habitually coupled with 
 the name of ftaly, from erroneous views of the nature and causes 
 of the fevers which I have here noticed, and from similarly mis- 
 taken ones respecting a vast body of other disorders, there are 
 persons who imagine that England is by nature exempt from this 
 scourge, let them return to its statistical and medical history for 
 two centuries past, and then see what was the mortality, not 
 merely of England generally, but even of London, from this cause, 
 Malaria. That a King of England should now die of a marsh fe- 
 ver, and that such a cause of death should excite no particular 
 surprise, is an opinion not to be entertained for an instant. Yet 
 thus died Cromwell, one among hundreds ; the death indeed not 
 without note, but its cause not esteemed out of the ordinary 
 course of mortality. Far otherwise, indeed, would such an event 
 be judged now , '" - ~ h i- which has been diminished, has not been 
 extirpated. True; England ls comparatively freed from this 
 plague, and it has been freed from it by industry and attention ; 
 
MALARIA. 7 
 
 but it is not yet exempt ; nor are we exempted from the further 
 exertion of that attention to which it is owing that the fens of 
 Lincoln are not the rivals in deadliness of Walcheren, and that 
 Romney is not what are the Pontine marshes. But knowledge 
 must precede industry and care ; and knowledge also must teach 
 us to prevent or diminish the evils where their cause is beyond 
 our powers. Such knowledge it is the object of this- essay to ex- 
 tend, or rather to teach ; since, however once known, it appears 
 to have been nearly forgotten, though never indeed understood 
 as it ought to have been. 
 
 But if we will not be yet persuaded to look about us at home, 
 let us look abroad, and not even to the tropical regions, but to 
 France, and Spain, and Holland, and Greece, and Italy, and then 
 ask ourselves whether the subject before us is not a subject of in- 
 terest. The value of life, of survivorship, the average chance of 
 approaching to the proverbial limit of threescore and ten, is the 
 measure of the salubrity of a country, and that salubrity depends 
 mainly on the presence or absence, the range or the limitation, of 
 Malaria. We may take the average of life among ourselves, in 
 round numbers, at fifty, with sufficient safety for this purpose. 
 In Holland it is twenty-five ; the half of human life is cut off at 
 one blow, and the executioner is Malaria ; for there is no other 
 cause for the superior mortality of that country. But there are 
 districts in France where it is but twenty-two, twenty, eighteen ; 
 so little is the chance of life; while all the instruments by which 
 Death executes his office, are here superseded by one, by that 
 one which renders all others unnecessary, which has monopo- 
 lized the functions of the whole dark catalogue — Malaria. Let 
 us turn to Italy : the fairest portions of this fair land are a prey 
 to this invisible enemy, its fragrant breezes are poison, the dews 
 of its summer evenings are death. The banks of its refreshing 
 streams, its rich and flowery meadows, the borders of its glassy 
 lakes, the luxuriant plains of its overflowing agriculture, the val- 
 ley where its aromatic shrubs regale the eye and perfume the air 9 
 these are the chosen seats of this plague, the throne of Malaria. 
 Death here walks hand in hand with the sources of life, sparing 
 none : the labourer reaps his harvest but to die, or he wanders 
 amid the luxuriance of vegetation and wealth, the ghost of man, 
 a sufferer from his cradle to his impending grave ; aged even in 
 childhood, and laying down in misery that life which was but 
 one disease. He is even driven from some of the richest portions 
 of this fertile yet unhappy country ; and the traveller contem- 
 plates at a distance deserts, but deserts of vegetable wealth, which 
 man dares not approach, — or he dies. 
 
 Nor do even his houses and towns afford him a shelter against 
 this all-pervSding pestilence. It enters with hira into his cham- 
 
8 
 
 MALARIA. 
 
 bers, and stalks through his streets. Imperial Rome herself is its 
 chosen victim : man flies before it, but the enemy is behind him 
 and around him on all sides : every day sees the dominions of 
 death extended, and the hour is impending when the Eternal City 
 will cease to be, when it shall submit to that fate, which has been 
 the fate of proud Nineveh, and Babylon the queen of nations. 
 
 Such also is Sicily, such Sardinia, and such is classic Greece. 
 To live a living death, to be cut off from more than half of even 
 that life, to be placed in the midst of wealth and enjoyment, yet 
 not to enjoy, such is the fate of man in the lands of Europe where 
 Malaria holds its chief seat ; while in the tropical regions, it is to 
 fall by thousands and tens of thousands, the summer harvest of 
 death walking hand in hand with that of the vegetable world. 
 
 True ; from thus much we are free ; and we may be grateful 
 for a security, purchased, as it is, by an ungenial climate, and a 
 soil less productive. But I shall soon show that our exemption 
 is far less perfect than we flatter ourselves ; that we too suffer, 
 and that we suffer from much which we might remedy or avoid. 
 But can we forget that we also suffer with Italy and with Greece, 
 with Africa and the West and the East, with the entire world ? 
 As travellers, as residents, as warriors, as colonists, we partake 
 with all ; and as they suffer, so do we. Let residents, let travel- 
 lers, let colonists say if it be not so. War at least cannot forget 
 what it suffers, what it has suffered, from this cause ; from that 
 Malaria of which it is too often ignorant, which, too often it 
 thinks fit to despise. If the sword has slain its thousands, the 
 Malaria has slain its tens of thousands. It is disease, not the field 
 of action, which digs the grave of armies ; it is Malaria by which 
 the burning spirit, fitted for better things, is quenched, and in the 
 coward's bed of death. This is the Destroying Angel, the real 
 pestilence which walks at noon day ; and to which all the other 
 causes of mortality are but as feeble auxiliaries in the work of 
 destruction. This is Malaria, the neglected subject to which I 
 am desirous of calling attention, that, by this, its powers may be 
 diminished : Malaria, from which even ourselves, here in England, 
 are not free, though, from ignorance, unaware of it, or from un- 
 willingness to receive conviction, shutting our eyes to the truth. 
 
 What other causes may here act in producing this incredulity, 
 let others say ; yet let me make one remark at least, while the 
 explanation I will as gladly leave to others. 
 
 It is a characteristic moral feature of those who reside in such 
 unhealthy situations in France, and a fact noticed by every one 
 who has examined those districts, to deny strenuously the exist- 
 ence of danger ; and to maintain that neither the soil which they 
 inhabit, nor the air in which they die rather than live, nor 
 their modes of life or labour, are unwholesome. Always ready, 
 
MALARIA. 9 
 
 and even ingenious, in excusing the place of their nativity or re- 
 sidence, they invent any other cause for their diseases, rather than 
 confess or believe in the true one ; and are even indignant at those 
 who would attempt to convince them, as if that were a reproach 
 and a calumny. This is not the feeling of Italy, it is true, more en- 
 lightened on this subject, or at least it is a rare one ; but it is a 
 very general one in Holland, as to which country it will perhaps 
 excite a smile in particular, to know that the people of Walche- 
 ren repelled with no small indignation, at the time of the celebrat- 
 ed visit of our troops, the charge of unhealthiness which was 
 brought against their beloved birth-place. 
 
 Nor is it less true of our own country, as I have said, if under 
 some difference of aspect and manner, perhaps, also, under some 
 difference of feelings. If ignorance cannot see, vanity, habit, un- 
 willingness to learn, or whatever else, supporting themselves also 
 on the general ignorance of the mass of practitioners, is ever ready 
 to deny the presence of Malaria in the indicated place, as it equal- 
 ly refuses to believe that any disorder, which is not a vulgar 
 " ague," in its most vulgar sense, can be the produce of this cause. 
 Far steadier is this obstinacy when the place in question is not a 
 marsh, since beyond a term do vulgar minds never reach ; while, 
 should it be a fish-pond, or the somewhat higher pretence, of the 
 same nature, with which they who imagine themselves gifted with 
 taste have projected to emulate nature, the clamour or contempt 
 become rivals of the obstinacy, and the naturalist, who would 
 demonstrate the identity, must be silent or yield— because marshy 
 ground is not a marsh. 
 
 That what is popularly called a marsh is not necessary to the 
 production of Malaria, is what I mean to show, and, 1 trust, to 
 prove, in this essay; to prove that the causes of Malaria exist 
 under numerous circumstances, not at all suspected, in our own 
 country, and in thousands, tens of thousands, of places, even at 
 our very doors. That it produces on the inhabitants, and from 
 these very sources, the same general effects as it does in Italy or 
 France, is what I also hope to prove ; as I shall further show that its 
 casual effects are the same, in the production of marked diseases, 
 and that the fevers of our own island are, very predominantly, 
 the marsh or remittent fever of the countries most subject to this 
 plague, though inferior in severity. Thus, also, in the medical 
 part of this work, or in the future volumes, if I shall prove that it 
 is a frequent, if not the exclusive, cause of a variety of torment- 
 ing, painful, and dangerous disorders, as also of what is called ill 
 health, very widely, I trust that it will no longer be a subject of 
 doubt, still less of contempt; and that the consequence will be a 
 considerable diminution of the evils which are produced by this 
 plague, and by the soils or situations in which it is generated. 
 
10 MALARIA. 
 
 This is the useful end, and the object in view ; correction of 
 the cause, or, if that be impossible, avoidance. To know the ex- 
 citing cause of a disease, is the first and most important step in 
 practical medicine ; it is to be furnished with the means of pre- 
 venting what, unfortunately, we cannot always cure ; pain which 
 we cannot mitigate, or death which we cannot prevent. Avoid- 
 ance is prevention, and, to a large extent, it is effectual. Better 
 still is the abolition of the cause ; but neither end can be gained, 
 until our knowledge is accurate and complete. 
 
 And if Malaria is that cause which I shall prove it to be, of dis- 
 eases numerically, and of instances of disease arithmetically, to 
 an enormous and little suspected amount, then must this essay, if 
 it be as true as I conceive it to be, become an auxiliary to prac- 
 tical medicine, of an importance not less, at least, than would be 
 a new and effectual mode of curing these disorders, including, as 
 they do, some of the most deadly, as well as the most refractory, 
 to which mankind is subject. And if thus, by prevention, effect- 
 ing more than even a method of cure could do, so is it to an ac- 
 curate and minute knowledge of the causes, of the exact spot, and 
 of every spot, productive of Malaria, that we must often resort, 
 even for the means of cure ; since it will be found, that the most 
 obstinate of these disorders are rendered incurable by repeated 
 but unsuspected applications of the cause, so that the mere avoid- 
 ance of that becomes the cure. 
 
 And if this inquiry thus forms a necessary portion of the merely 
 medical part of this work, not less will it prove useful to the peo- 
 ple as a practical guide towards the avoidance of diseases, endless 
 in variety of character as in variety of evil, and which, in the in- 
 finitely greater majority of cases, are the produce of this very ig- 
 norance ; of want of knowledge, or want of suspicion, as to the 
 existence or presence of Malaria. If they were thus taught but 
 to avoid the fevers which, in most cases, are the produce of this 
 ignorance, fevers which, in every summer, are committing their 
 ravages even in our towns, and which a very little caution would 
 often prevent, it would be no small gain ; but when we add to this 
 the endless list of other disorders, chronic or acute, the torments 
 of entire families, or the cause of misery to individuals beyond 
 numbering, the impediments to business and industry as to com- 
 fort and happiness, and all of these but too generally the conse- 
 quences of similar ignorance, I cannot help thinking that to spread 
 such opinions as widely as possible, and to enforce them as strong- 
 ly as possible, is a duty, and a duty which will not fail to be re- 
 warded at least by some success, hereafter, if not at present ; 
 while the only reward which has here been contemplated, is that 
 success; the conviction of having aided in diminishing human 
 suffering. 
 
MALARIA, 
 
 11 
 
 I must now proceed to describe the various facts which relate 
 to the production and propagation of Malaria ; but as I shall have 
 to encounter abundance of incredulity or prejudice, it will be ne- 
 cessary to commence by stating the nature of the evidence as to 
 the actual existence, in particular cases, of a poison, which is, 
 from its very nature, invisible, which has hitherto entirely eluded 
 all chemical investigation, and which can be detected only by its 
 effects on the human body. This is a justice which is due to a 
 reader ; since no one can or ought to be contented with the mere 
 assertions of individuals, however numerous or reputed, or what- 
 ever their own convictions may be ; and it is the more necessary 
 to the reader of our own country, since, on a subject never be- 
 fore submitted to an English public, it would be natural to expect, 
 at least, both ignorance and incredulity, did we not even know 
 that there were also prejudices in abundance to be surmounted. 
 
( 12) 
 
 CHAPTER II. 
 
 Nature of the evidences respecting the production of Malaria in 
 situations of a less notorious or acknowledged character. 
 
 It is admitted on all hands, that what is called a marsh or a 
 swamp, is capable of producing fevers ; and, in our own country, 
 this is more especially believed respecting the intermittent ones, 
 or, as they are popularly termed, agues. This particular class of 
 causes, or localities, will require, therefore, no such proofs as I 
 am here contemplating, though they must be included in the ge- 
 neral enumeration. 
 
 It is not so, however, with regard to all ; and in enumerating 
 the less admitted sources of Malaria, I shall, therefore, be often 
 compelled to resort to proofs of some delicacy, and to appeals to 
 an experience for which, be it received as it may, I must be very 
 often myself responsible. It becomes, therefore, necessary, as a 
 preliminary step, to state the reasons from experience, whence 
 particular soils or qualities of land, many of which have hitherto 
 been unsuspected, have been here judged productive of Malaria ; 
 and where these observations have been multiplied, as has here 
 been the case, there is no reason why we should not generalize 
 for the several causes of this less obvious nature, as has been done 
 in the case of marshes. And if the generalization is not univer- 
 sally true, if exceptions shall be named, as they doubtless exist, 
 it must be remembered, that this is no more than happens with 
 regard to even the most notorious causes, marshes and jungles, 
 and to these, even in tropical climates, as will be shown here- 
 after more particularly. In all cases of philosophy, exceptions 
 occur, until we are masters of all the causes that produce and in- 
 fluence an effect ; while, instead of proving the rule, as is com- 
 monly said, they prove that we do not know that rule ; and if 
 there are exceptions in this particular case, it is no ground for 
 surprise, ignorant as we in a great measure are, of the precise part 
 or action of a soil which generates Malaria. 
 
 It is a fundamental fallacy in this case to limit our decision on 
 the power of any soil or situation in the production of this poison, 
 by the occurrence of regular intermittent fever, or common ague ; 
 and yet it is a leading and a common fallacy, in our own country, 
 even among physicians. The practitioners acquainted with hot 
 countries know indeed perfectly well, that the common fever of 
 summer and autumn, be its names what they may, is equally the 
 
EVIDENCES, &C. 13 
 
 produce and proof of Malaria ; as this is also known to all physi- 
 cians of reading, who have not had the advantage of similar expe- 
 rience. To them it is equally known, that dysentery is produced 
 by the same causes, while, at present, I need not extend this enu- 
 meration. 
 
 But this is as far from being true of the mass of domestic, un- 
 travelled, and imperfectly educated practitioners, as it is of the 
 mass of the people themselves. With these, the fevers in ques- 
 tion are most frequently called typhus, and, further, generally 
 considered as contagious ; such is the laxity still prevailing, al- 
 most, I might say, universally, on this subject ; of which, if it 
 were not disagreeable to recollect, and painful to recal to the 
 minds of those in fault, one notorious instance, among innumera- 
 ble others, not very distant in time or place, and noted for its se- 
 vere consequences, might be quoted ; while the term bilious fe- 
 ver, sometimes used by others, conveys ideas no further definite, 
 particularly as the cause is generally sought in heat, cold, fatigue, 
 fruit, even in plums and cherries specifically, and while the au- 
 umnal dysentery is attributed to the same fanciful causes. 
 
 Having, therefore, set aside this fallacy, the real conclusion to 
 be drawn is, that wherever remitting fevers, or fevers of what- 
 ever nature that are not contagious, as well as dysenteries (to say 
 nothing at present of other diseases less commonly attributed to 
 this cause), are produced, the proof of summer Malaria is as com- 
 plete as if the same soils had, in spring, produced ague; or, gen- 
 erally, that as the same soil, in different seasons, or under differ- 
 ent circumstances, produces both kinds of disease, or the differ- 
 ent species of one genus, while both are mutually interchange- 
 ible, so the occurrence of any species at any season, is a proof 
 that the situation is productive of Malaria. 
 
 Now, to apply this to the desired proof, as to the poisonous 
 quality of unsuspected situations, it will be found by any careful 
 observer, that there are certain determinate places, where never- 
 theless no marshes are present, in which there are annually, or 
 generally, fevers produced or existing, while others, even in the 
 immediate vicinity, are exempt ; and, in these places, a careful 
 nquirer will find that some one of the various circumstances of 
 oil shortly to be pointed out, is present. 
 
 Further, and to come to a more delicate and a scarcely ob- 
 erved species of proof as to the presence of Malaria in certain 
 situations, it is quite notorious that some places or soils are, in 
 eneral terms, unhealthy; a remark as familiar with the people 
 it large as with medical practitioners. Thus it is a vulgar re- 
 nark, that in certain houses or places, a family is rarely without 
 some sickness ; or, to use the strong but coarse language in which 
 t is generally stated , " that the apothecary is never out of the 
 
14 EVIDENCES OF 
 
 house,'" It is almost equally familiar, that families, which had 
 before been healthy, have become the reverse on changing 
 houses or situations ; as, in the opposite cases, that they have re- 
 covered health by change of residence. Of such facts as these, 
 there is no observer who must not be able to recollect numerous 
 examples. 
 
 As may be expected, there is seldom any backwardness in as- 
 signing causes for the unhealthiness of such places ; since the low- 
 est of the ignorant are not less fond of causation, in their own 
 way, than philosophy itself. Thus, to be damp, to be low, and 
 so forth, are obvious physical facts, and easily accused as causes ; 
 while medical men, with an unpardonable carelessness, or absence 
 of reasoning, too generally rest in the same vague and indefinite 
 language, satisfying themselves, as is too common, with words. 
 Thus it also is, that we find even those from whom we should ex- 
 pect more accuracy of thinking, concluding that a given situation 
 or district is unhealthy, and even without asking themselves 
 what are the diseases of this ill health, because the soil is clay ; 
 or reversely, healthy, because it " lies on a gravelly bottom," or 
 is a land of chalk ; concluding, when they do conclude at all, that 
 clay is a pernicious substance, or resting in some vague and loose 
 notions about moisture, cold, porosity, drainage, or what not. 
 
 This is a pernicious laxity, both of thinking and phraseology, 
 because it turns the attention from the real evil, and, preventing 
 the discovery of the true causes, equally impedes that of the re- 
 medy. To anticipate, but no more than is here necessary, what 
 must shortly be said on the subject, if a gravelly soil is healthy, it 
 is because its easy drainage prevents the growth of that particu- 
 lar vegetation which is the cause of Malaria ; and if a clayey soil 
 is the reverse, it is because, by lodging superficial water, it gene- 
 rates, however partially, those marshy or undrained spots, or wet 
 woods, or moist meadows, which are the sources of this poison, 
 and, consequently, of the various diseases confounded under the 
 vague term unhealthiness. But as there are cases without end 
 where gravelly soils do contain spots generative of Malaria, while 
 clayey soils are, over large tracts, often as dry, and therefore as 
 healthy, as the most porous ones, it is plain that this laxity, both 
 of observation and language, is in every way pernicious ; since, 
 from not seeing the real cause, it can never be decided where 
 health may reside or disease be produced. 
 
 Now, to recur to this kind of "unhealthiness," as it is termed, 
 attached to particular houses or situations, as affording evidence 
 of the existence or generation of Malaria in places little suspect- 
 ed, or, rather, not at all suspected, and most generally denied, 
 both by the inhabitants and their physicians, it will be found, on 
 a rigid examination, that it consists very often in the occurrences 
 
MALARIA. ] 5 
 
 of summer and autumnal fevers ; a case, we might suppose, suffi- 
 ciently evincing the real cause, were it not for the almost univer- 
 sal laxity of opinion among medical practitioners respecting the 
 nature and causes of these fevers. But whether decided or 
 marked fevers occur or not, it is usual for the inhabitants of such 
 places to suffer, almost perennially, or with periods more or less 
 durable, of tolerable health, from a vexatious and frequent recur- 
 rence of petty fevers, or of a general febrile state, very often re- 
 ferred to dyspepsia, to nervous ailments, or to any other conve- 
 nient and fashionable cause; while this condition of the body, . 
 sometimes following decided and severe remittents, often occurs 
 without them, producing that general and obscure continuence of 
 ailment which is called ill health. 
 
 An acute and unprejudiced observer, taking this view as his 
 guide, may easily satisfy himself of the real nature of the " ill 
 health" in the situations now under review ; but he will also find 
 that this does not constitute the whole of the diseases thus pro- 
 duced ; as, if he will review his own practice on such inhabi- 
 tants, he will find dysentery, often, or generally, called diarrhoea, 
 one of the prevailing ailments, and, perhaps, cholera ; together 
 with headaches, periodical or irregular rheumatism of the face or 
 head as it is called, toothach, sciatica, with tic douloureux, or 
 other varieties of neuralgia, bilious affections, as the phrase is, 
 and a whole catalogue of all the nervous ailments which, at dif- 
 ferent periods, under different fashions, have been attributed to 
 various causes ; to the nerves, the spleen, the stomach, the liver, 
 and now, as is a far more convenient phraseology, to the chylo- 
 poietic viscera. 
 
 Even if all these should be absent, or if from fortitude, care- 
 lessness, poverty, or from weariness or contempt of physic, per- 
 sons who are thus habitual and hopeless sufferers, should not 
 give a physician all the opportunities of minute observation which 
 he might desire, he will be a bad observer if he does not disco- 
 ver in the sallow complexions, the langour, the irritable tempers, 
 or the melancholy character of individuals thus unfortunately 
 situated, that they are suffering under fixed derangements of the 
 larger glandular viscera ; often of the liver, and perhaps much 
 more frequently of the spleen. And should he have those oppor- 
 tunities of examination which severe diseases of this nature af- 
 ford, he will be enabled to convince himself that this very spe- 
 cies of disease, the noted produce of the places that notoriously 
 generate Malaria in the hotter climates, is also habitual to the 
 similar situations in our own country, if under a less severe cha- 
 racter ; and that it is one of the leading causes of that indefina- 
 ble ill health peculiar to the situation of the patient, as it is, ap- 
 
16 EVIDENCES OF 
 
 parently, the great cause of so many distressing, nervous, and 
 dyspeptic symptoms. 
 
 The whole condition, in fact, of a people so situated, as I have 
 now sketched it, is precisely that of the inhabitants of the pestif- 
 erous districts of France, Italy, and elsewhere ; since in these, 
 and independently of the noted epidemics, or the occasional se- 
 vere or marked fevers, the population is, perennially, and even 
 through life, subject to a whole catalogue of chronic ailments ; 
 the only difference being, that in our own far less unwholesome 
 districts of a similar character, these are less violent, and, also, 
 commonly less perennial and less durable. 
 
 Such are the evidences, derived from the production of abso- 
 lute disease, whence it is here judged that particular situations, 
 often little suspected, are productive of Malaria ; because that 
 poison, where its generation can be demonstrated in the produc- 
 tion of the acknowledged diseases of which it is the cause, pro- 
 duces all these obscurer diseases also, and because these situa- 
 tions do actually contain the same elements which constitute 
 marshes or soils generative of this poison; the difference consist- 
 ing in nothing but slender modifications of form or distribution, 
 or variations of dimension. 
 
 But it must be added, also, as an unanswerable argument, " that 
 these very spots are known to produce the common intermit- 
 tent ; and thus, while they demonstrate their power in generating 
 Malaria, even to those who know of no test but this common 
 one, they also aid in proving that all the concatenated diseases 
 just enumerated depend on the same cause, occurring, as they do, 
 in the same persons, often the sequel of intermittent or of remit- 
 tent, and notoriously common in the situations in question, while 
 rare in others. Unquestionably, the marked and regular inter- 
 mittent is by no means necessary, nor, perhaps, even common, 
 in these places ; but the force of the argument derived from it 
 will not be injured by that exception. We are not bound to ex- 
 plain this, until we can also explain why intermittent is not al- 
 ways produced where remittent is generated, why certain coun- 
 tries abounding in the remittents of autumn do not produce the 
 intermittent of spring, while the reverse is also not uncommon; 
 or why the rice fields of Bengal, if that be true, are not as poison- 
 ous as those of Lombardy. This is the misfortune of our igno- 
 rance at present ; and it is a difficulty that will not be solved till 
 we become acquainted with the immediate nature of Malaria, or 
 at least with the immediate chemical actions under which it is 
 produced. 
 
 It remains to mention one more fact, and in the nature of a 
 test, if such a term may be used, by which the power of any giv- 
 en place in producing Malaria may be determined. Hereafter, 
 
MALARIA. 17 
 
 chemistry, striding on as it does with such unexampled rapidity, 
 may, perhaps, put us into possession of a test of its own, by which 
 we may be enabled to determine its presence as easily as we now 
 do that of oxygen or carbonic acid. Till then, we must be con- 
 tent with what we can command ; and the test here alluded to is 
 human susceptibility. 
 
 It is notorious, that those who have suffered severely and re- 
 peatedly from intermittent, or, sometimes, from remittent, be- 
 come, and even through a long course of years, so highly suscep- 
 tible, that the slightest exciting cause, and, among others, the 
 slightest application of Malaria, is capable of reproducing the dis- 
 ease. That this is true of the host of sufferers at Walcheren, 
 needs not be said ; while it has been also found common among 
 those who have suffered from the intermittents of China or of 
 Canada; as indeed of many other countries, among which Mol- 
 davia is said to be pre-eminent. Hence, therefore, where we 
 find that such a person has experienced a renewal of his disorder, 
 from communication with a place otherwise suspicious from its 
 nature, it offers as convincing a proof as can be desired, that 
 there Malaria is produced or producible. 
 
 It is true that there may be, and there in fact are, places, 
 where, apparently from the small quantity or moderate intensity 
 of the poison, persons in health, to whom these diseases have 
 been unknown, may not suffer at all ; while this negative is often 
 used as an argument in favour of their salubrity. But it is a ne- 
 gative which proves nothing, if the effect can be produced upon 
 any one individual ; while it must be remembered that it is a very 
 injudicious argument to repose on, when it is known, that in cer- 
 tain seasons, places which are but moderately unhealthy become 
 extremely dangerous ; and there is never any security that where 
 the poison exists at all, it may not at some day be called into 
 complete action. Let it be remembered, also, that accessary 
 causes, causes that will be enumerated hereafter, must often con- 
 cur, and that many persons are unsusceptible of the poison, as 
 some are of small pox and other diseases ; facts which, it is easy 
 to see, will have an additional influence when the Malaria is not 
 existent in great abundance, or when its virulence is inferior to 
 that which it displays in the hotter climates. 
 
 There is a pride indeed in foolhardiness, but it is a sufficiently 
 silly one ; while there are abundant useful or necessary hazards 
 which every one may encounter, if he pleases, and which many 
 must brave, however unwilling. There is little merit in courage 
 where there is neither duty nor utility ; but if some, as is but too 
 true, cannot quit the places where their lot has been cast, nor 
 entirely avoid the hazards to which their modes of life may sub- 
 ject them, there is still much to be done in avoidance and pre- 
 
18 EVIDENCES OF 
 
 caution, which will be discovered hereafter, in the course of this 
 essay ; while it is satisfactory to reflect that our sufferings were 
 at least the inevitable results of our duties, and that we have not 
 aggravated them by our own want of prudence or want of know- 
 ledge. 
 
 I am almost ashamed, on this subject, to answer such an argu- 
 ment as the following ; and yet it is by such arguments that the 
 people at large do defend their opinions ; while I must not forget 
 of what the mass of mankind is composed, nor who my readers 
 may be. A resident in a Lincolnshire fen dies of a remittent fe- 
 ver at the age of thirty or forty. The cause cannot be in the pes- 
 tiferous spot, it is said, else the man should have died at twenty, 
 fifteen or ten. The answer does not seem very remote, and 
 needs not be very long. At Mantua, at Ferrara, at Syracuse, at 
 Cagliari, no one should live at all ; every man should die at the 
 hour of his birth. I need not be more explanatory ; let others 
 complete the answer. 
 
 If I have now dwelt at some length on the evidences from 
 which I shall shortly enumerate certain little suspected situations 
 as generative of Malaria, it is because I consider the assignment 
 of these as a matter of the greatest importance, inasmuch as the 
 health of the people must very mainly be affected by their know- 
 ledge or ignorance in this respect. It is by knowledge and con- 
 viction of what is insalubrious that they will avoid ill health and 
 death, as far as inevitable duties or circumstances permit ; as it 
 is by ignorance that they will run themselves into dangers and 
 sufferings which they might have avoided. 
 
 And it is only thus, also, that those remedies which consist in 
 altering the nature of poisonous situations can be applied, appli- 
 cable as we know them to be. There was a time when our rude 
 ancestors did not know that their poisonous marshes were the 
 causes of pestilence and death. This we have learned, and have 
 profited accordingly. But we have not learned all ; though, with 
 the usual conceit that attends on every new step in improvement, 
 we would fain believe that we have nothing more to acquire. 
 
 It will be seen, when the classes of soil and situation which I 
 am shortly to point out shall be enumerated, that there are many, 
 very many cases, in which either the remedy, the remedy of pre- 
 vention, is easy, or where the hazard, always incurrred through 
 ignorance, needs not be encountered. But, for these ends, they 
 must be known ; and, for these ends, further, the people must be 
 informed, or rather convinced. My duty, as it is my design, is 
 to make them known ; let he who has the power of convincing 
 mankind that they have been in error, and that they are ignorant, 
 undertake the other task. But time effects what man cannot ; 
 and hereafter, perhaps, an English gentleman will be as much sur- 
 
MALARIA, 19 
 
 prised that his neighbour should dig a sleeping canal before his 
 door, as that his feudal ancestor should have built his castle in a 
 marsh, and inclosed it within a putrid moat. 
 
 To suggest that he who does this is sowing the seeds of dis- 
 ease, that he may reap the fruit of fevers and apothecaries' bills, 
 is to excite the smile of superciliousness or contempt; as he must 
 long yet submit to be the object of both, who would try to con- 
 vince mankind that the pond which has been constructed for a 
 few gold fishes, or the river which meanders through the woody 
 valley, is a death-spring of diseases, or that the fevers and the 
 tooth-aches which are the torments of his family, the ailing wife 
 who is his own torment, and the sciatica which is the torment of 
 his poorer neighbours, are the produce of a few bunches of rush- 
 es, or of a splendid display of waterlilies. Yet the time is not 
 very long past, it is not every where past yet, when the intermit- 
 tent itself was supposed to be salutary, when a " spring ague" 
 was esteemed such a blessing as persons of similar powers of rea- 
 soning even now esteem the gout ; and the time will also arrive, 
 when he who has smiled at this philosophy, will, in his turn, be 
 the object of a smile to the heir who shall expend in laying dry 
 as much as his predecessor wasted in inundating. 
 
 The obscure cases in question are very principally such, that 
 while prevention is generally easy, either by amending an exist- 
 ing bad situation, or avoiding an incurable one, it seems espe- 
 cially called for, from their number, as well as from the number 
 and the inveteracy of the diseases thus generated. Let me urge 
 what I said before, that Malaria produces, in itself, a far wider 
 mass of human misery than any other cause of disease ; as, for 
 the world at large, it is also the cause of far more than half the 
 mortality of mankind. And that many of the diseases which it 
 produces are almost beyond the power of physic, while marked 
 by a resistance which often terminates but with life, is an addi- 
 tional reason for making every exertion to avoid what we know 
 not how to cure. And further, if I am myself fully convinced by 
 wide observation, it would also not be difficult to prove, that this 
 very persistence, the cause of so much misery, is most generally 
 the result, not of a fixed disease, of organic affections, as com- 
 monly supposed, or of inveterate habit, but of incautious or un- 
 known, and repeated or continued exposure to the re-exciting 
 cause, Malaria. 
 
 Hence, if the diseases from this cause are incurable in the 
 places where they arose, as is notorious in every marked situation 
 of this nature throughout Europe, so it is from repeated exposures 
 to Malaria that they are renewed, even under change of place ; 
 and from ignorance, generally, of the situations, too often unsus- 
 pected, which are productive of the poison. He who labours 
 
20 EVIDENCES, &C. 
 
 under an incurable intermittent in England, is perhaps sent to 
 Italy or France for change of air and a cure; as thousands are 
 daily sent, for other reasons, to the same countries. The phy- 
 sician forgets, and the patient knows not, that he is flying Scylla 
 to rush into Charybdis, and too often confirms the disease or 
 meets the death which he meant to avoid ; while he who hopes to 
 leave consumption behind him at Montpellier, leaves it indeed in 
 the grave where the fever has superseded his more tardy enemy ; 
 as he who flies from poverty and England to the banks of the 
 Rhone or the Loire, finds too late that he has bartered his health 
 for the expected ease and happiness of France. 
 
 And thus, even in England, it is the Malaria, lurking in a thou- 
 sand unsuspected places, which perpetuates, if it does not pro- 
 duce, those diseases which are the curse of thousands, rendering 
 life a burden to the owner, and depriving him of those powers 
 for the use of which he was created. If, with these views, the 
 cases which form the subject of the fourth Chapter, are especially 
 enumerated, both minutely and strongly, if even any one instance 
 should prove unfounded, it is much better that we should err by 
 superfluous precaution, and even through groundless fears, than 
 by ignorance and rashness. I am fully willing to bear the blame 
 of exaggeration, if exaggeration shall be proved ; or the ridicule, 
 should that be the weapon preferred : holding little of the civil 
 courage of him who, with such an object in view as the benefit 
 of mankind, is not ready to submit to that which has ever been 
 the lot of those who undertake to do good to others, against their 
 will, and in spite of their prejudices or ignorance. 
 
(21 ) 
 CHAPTER III. 
 
 Oh the soils and situations which most commonly produce 
 Malaria. 
 
 if is as superfluous to describe what constitutes a marsh, as it is 
 unnecessary to insist on what is universally admitted. 'But this 
 condition of land is subject to so many diversities of character, 
 and such variations, that it is by no means superfluous to notice 
 some of them, particularly where they are, in the popular opinion, 
 esteemed innoxious ; as it is only by cautioning the people respect- 
 ing these unsupected evils, that we can succeed in diminishing 
 the production of this class of diseases. 
 
 Now, to commence, while it is generally believed that marshes 
 of fresh water are, even in our own island, productive of Malaria, 
 it is a scarcely less common popular conviction, that salt marshes 
 are innocent in this respect. Whatever may be true of the nor- 
 thern and colder parts of Britain, no observer can doubt that 
 Malaria is produced by salt marshes in the southern parts, and, 
 as might be expected, most conspicuously in hot summers ; the 
 examples being found in so many places that it is unnecessary to 
 name them, since the difficulty would be to find the exemption. 
 
 Could any doubt indeed remain about this, it would be remov- 
 ed by the examination of this kind of soil over almost the whole 
 world. The salt marshes of Normandy, of which the country 
 round Dol may be taken as a sample, are notoriously productive 
 of intermittents, to such a degree, that scarcely an inhabitant is 
 exempt from them ; while the general effect on the population is 
 what is usually produced in such cases ; a condition which will 
 fall under review hereafter. It is the same op the French shores 
 of the Mediterranean ; it is the same in the Adriatic, on both 
 shores, as it is in Greece and Italy generally, and as it is in Sicily, 
 in Sardinia, in the Crimea, in Spain, every where, in short, in 
 the middle and southern parts of Europe ; and it is equally true 
 of every part of the African, Asiatic, and American continents, 
 at least within the range of heat, which, however indefineable, 
 extends far beyond the torrid into the temperate zones. 
 
 It is perhaps superfluous to add here, what, if not strictly the 
 same, is so far analogous as to admit of being quoted, and of which 
 examples might equally be drawn from many other parts of the 
 world. 
 
 D 
 
22 SOILS AND SITUATIONS 
 
 It has frequently been remarl&d in Holland, that the severesi 
 seasons of fever have followed casual irruptions of the sea, and 
 also that, on these occasions, there has been produced a degree 
 of putrifaction, attended with an insufferable smell, unusual in 
 other cases ; a fact which, if not necessary to the generation oi 
 Malaria and fever, still marks an ultimate degree of that vegeta- 
 ble decomposition which, in some previous condition, is capable 
 of producing the peculiar substance which is the cause of the dis- 
 eases under review. Nor is there any reason why this, and many 
 other similar and analogous facts, should not be true ; since we 
 know that the decomposition of dead vegetable matter takes 
 place as effectually and readily in salt water as in fresh. It has 
 even been asserted by many writers on this subject, both in France 
 and Italy, that the putrifaction is more rapid wherever salt and 
 fresh water intermix, and that salt marshes are consequently more 
 pernicious than fresh ; the well known experiments of Sir Johu 
 Pringle on the effects of small quantities of salt in aiding this pro- 
 cess, having been quoted in support. Facts, in confirmation oi 
 these opinions, are quoted from Leyden in 1679, where an acci- 
 dental event of this nature produced a very destructive fever: 
 from Martigues in France, and elsewhere; but whatever the 
 value of the theory may be, there seems no reason at least to 
 doubt that other circumstances being the same, it is at least in- 
 different whether the marsh be salt or fresh. 
 
 Further, it is a popular prejudice, and a somewhat more defin- 
 ed one on the same subject, that however such soils may produce 
 Malaria when exposed for any length of time, their injurious 
 qualities are remedied wherever they are washed by the sea. 
 But for this also there seems no ground ; however difficult it may 
 be, without an accuracy and extent of personal examination 
 which must ever be impossible, to be satisfied that, in situations 
 of this nature, there is not some portion or spot present, indepen- 
 dent of that which is subject to daily inundation from the tide. 
 Others must attempt to investigate the truth here, as far as they 
 can ; but, in the mean time, the testimony of all voyagers seems 
 to establish, that there are few places more productive of Malaria 
 and fevers than the palm and mangrove rivers of the tropical cli- 
 mates, as I shall have occasion hereafter to show more particu- 
 larly ; while the characters of these are too well known to re- 
 quire description. Perhaps similar doubts as to the exact purity 
 of the observation may sometimes attach in our own country ; 
 yet there are few tracts in England more productive of a Malaria, 
 which is even of a virulent nature, than Heron bay and the river 
 banks in general about Reculver, where the water is salt, and the 
 whole is covered twice in the day. The same indeed is true of 
 so many parts of England, that the enumeration would be equal- 
 
WHICH PRODUCE MALARIA. 23 
 
 \y tedious and superfluous. Be the truth, however, what it may, 
 in this case, it will be always the most safe belief to adopt the 
 opinion and to act on it; as the philosophical evil of the error, if 
 it be one, bears no comparison to its value as a practical secu- 
 rity. 
 
 The power of woods in generating Malaria is not less notori- 
 ous than that of marshes, at least in the tropical climates. To 
 repeat all that has been written respecting this particular class of 
 soils, would be to compile without purpose. The jungles and 
 the jungle fevers of India are as familiar, even to the multitude, 
 as the ditches and fevers of Walcheren. The jungle, it must how- 
 ever be remarked, is a low and dense brushwood, or a thicket of 
 reeds and grass ; and it is often, consequently, as the residence of 
 moisture and decaying vegetation, analagous to a marsh. Yet 
 the production of fever does not seem limited to this particular 
 species of woods in India; since, according to the testimony of 
 Buchanan, confirmed by that of others in several parts of the East, 
 fevers are produced among the opener and larger forests, in My- 
 sore and elsewhere, and are in fact the usual concomitants of all 
 woods. 
 
 Yet in this matter, and even in those climates, there appears 
 some irregularity, as far at least as we can judge from the reports 
 of ordinary travellers ; since it is said that, in Cambodia, Cochin- 
 china, and Siam, there are extensive tracts of wood where fevers 
 are unknown. As to Africa, the same rules seem to apply, as far 
 as it is known to us ; and the same also seems true of the warm- 
 er regions of America, however the opener and drier pine forests 
 may be exempt. I need not here notice the mangrove woods, 
 because they have been mentioned as a variety of salt marshes, 
 and will come under review again for another purpose. But I 
 may be allowed to remark, that what I have quoted respecting 
 the woods of those peninsulas and shores which intervene be- 
 tween Bengal and China, does not appear matter of authority ; 
 particularly when the same traveller remarks that, reversely, the 
 plains of these countries are insalubrious, while those of Bengal 
 are healthy; since this assuredly is not the fact. Though it is the 
 remark of an acute general observer, it must be supposed one of 
 those errors of observation not unusual with those who have not 
 been exerting their attention on a particular subject. 
 
 Even in the warmer climates of Europe, as well as in the cold- 
 er ones, very little suspicion seems entertained respecting woods; 
 yet while there is much reason to doubt their exemption from 
 Malaria in our own quarter of the globe, I have no absolute evi- 
 dence against them to produce, from the writings of physicians 
 and economists, or none at least which is very definitive. It is 
 possible that they may have been overlooked amid districts where 
 
24 SOILS AND SITUATIONS 
 
 there are other causes present in abundance ; as it is easy to at- 
 tribute to the open soil, what may, in reality, be the produce of 
 the wood in its neighbourhood. If there are scattered facts, which 
 seem to prove my conjectures respecting their pernicious proper- 
 ties right, I am unwilling to quote them ; since there is so much 
 more of foreign inquiry on this subject, which I must needs leave 
 to a future investigation and to others ; intending this, as I do, ra- 
 ther for a stimulus to future inquirers than as an entire inquiry in 
 itself. I have a far other opinion of the extent and importance oi 
 this subject, than to suppose it capable of being adequately treat- 
 ed in a sketch so slender as this is meant to be : and if, in the 
 hands of Italian writers, this question, even as it relates to their 
 own country alone, has often occupied three or four volumes, 
 each as bulky as my own, I need not surely say that 1 have not 
 here exhausted the subject. 
 
 There is the more reason for thinking that close and wet woods 
 in general, throughout Europe, at least in the warmer parts, pro- 
 duce Malaria, from the fact of their unquestionably producing il 
 in our own country. If any one will examine the districts in 
 Sussex and Kent which produce both intermittent and remittenl 
 fevers, he will often be unable to assign a cause, unless he seeks 
 it in the woods, which, from their characters, seem amply com 
 petent to this effect. And we must often explain, in the same 
 manner, the occurrence of these fevers, in the form of habitua: 
 endemics, in Hampshire, as well as in Essex : occurring, in the 
 latter, in the center, and on the borders especially, of Eppinc 
 forest, in the higher grounds, even where the soil is gravelly, and 
 being by no means limited, as is popularly imagined, to its flat wei 
 meadows or marshy tracts. And, in a similar manner, it is founc 
 that autumnal fever occurs, even in Wales, and among the grounds 
 of the higher vallies, in the vicinity of phashy woods and coppices 
 and even where these are situated on the steep declivities of the 
 hills. Let others who have better or other local opportunities 
 extend these proofs by adequate investigations ; since, to any one 
 inquirer, the means of such examination must necessarily be 
 limited. 
 
 But there are some general facts belonging to this questior 
 which must not be passed over, particularly, as, for want of making 
 some necessary distinctions, there will be found, in writers, con 
 siderable contradictions on this subject. However I might wisl 
 here to examine the whole, it would infringe on the order of this 
 essay, to notice at present what belongs rather to the propagation 
 than the production of Malaria; and I can only regret that it is 
 nearly impossible to prevent the different branches of this inquir) 
 from interfering with each other. 
 
 If woods or trees do, in certain and sufficiently numerous cases, 
 
WHICH PRODUCE MALARIA. 25 
 
 generate Malaria, and thus render a district unhealthy, they are 
 also often a safeguard ; or a country which was before healthy, 
 {may become the reverse by cutting them down. In such cases, 
 j the poison is actually produced sometimes by this change ; in 
 others, the propagation merely is facilitated or extended. As a 
 ;| proof of the former fact, Rush has observed, that, in Pennsylvania, 
 j epidemics invariably follow the clearing and cultivation of forest 
 .lands, and that they do not disappear till after many years of con- 
 tinued agriculture. The same remark has been made in France ; 
 and the district of Bresse (Lyonnais) which was comparatively 
 healthy when full of woods, has become nearly depopulated since 
 they were cut down. In this particular case, as in some others, 
 the facility of propagation has probably been increased, and may 
 have been the main cause ; but in that of America, above cited, 
 and in others, in addition to the mere circumstance of breaking 
 up the land, the cause will be found in the action of the sun on 
 the wet ground, previously guarded from it by the shade of the 
 trees. It is a more general cause, if one which operates more 
 slowly, thatthus also the climate is improved, or becomes warmer ; 
 a fact of which there is abundant evidence all over the world ; 
 and thus, even over a whole country, the production of Malaria 
 may be increased. To this general effect I have alluded in speak- 
 ing hereafter of Rome ; and it is not probable that it has had a 
 very extensive influence all over Europe, and indeed in America 
 also, however counteracted by improvements of various kinds ; 
 since, as is familiar, the whole of our division of the world has 
 undergone an immense change in this respect, or a general aug- 
 mentation of its temperature, since the times of classic antiquity. 
 Reversely, it follows that the planting of trees will sometimes 
 check the production of Malaria, by protecting wet lands from the 
 action of the sun : while by absorbing and dissipating the mois- 
 ture, and not less by destroying, through their shade, an injurious 
 vegetation, they may act in other modes not less salutary. There 
 is a real truth therefore in Pliny's remark, elsewhere quoted, that 
 trees destroy or consume the mephitic vapours; however inaccu- 
 rate his philosophy may be on this subject. 
 
 It is plain, therefore, that even independent of the effects of 
 
 trees as relates t& the propagation of Malaria, a circumstance in 
 
 itself of great delicacy to understand or manage, it will require 
 
 j considerable attention and reasoning, and those directed to the 
 
 i precise spot in question, to determine on planting or the reverse, 
 
 j when the object is to correct an unhealthy soil by such means ; 
 
 while nothing more can here be done than to furnish the general 
 
 principles by which any such attempts must be guided. 
 
 To say that rice grounds are productive of Malaria, is equally 
 to state a fact notorious to the whole world ; while the causes, 
 
26 SOILS AND SITUATIONS 
 
 consisting in a succession of inundation and drainage, approximate 
 them in character to swamps and marshes, however obscure the 
 immediate operation of either in producing this poison may be. 
 How extensively Italy suffers from this cause, it is quite super- 
 fluous to say ; since the mortality in Lombardy, and elsewhere, 
 arising from it, is matter of daily observation, even to the most 
 incurious travellers. And the same is true of Greece and Sicily, 
 as it is generally of Europe, wherever this grain is cultivated. 
 
 In France, the same remarks have been made, far too exten- 
 sively and by observers too accurate, to leave it a matter of doubt ; 
 it having been further demonstrated, that this cultivation has in- 
 troduced disease where it was unknown before, and materially 
 augmented that of lands where Malaria had formerly existed in a 
 moderate degree. Here, as in Italy, not only are the usual sum- 
 mer fevers produced, but the inhabitants are, in the same manner, 
 the victims to visceral obstructions and dropsies, as to all the 
 other ailments elsewhere enumerated. It is even stated, on au- 
 thorities which seem to admit of no dispute, that in those districts 
 the term of life does not exceed forty, and that the population is 
 decimated in every year. In certain parts of Russia, and point- 
 edly near Oczacow, the cultivation of rice is prohibited for this 
 reason ; and it is well known that a similar intention as to cer- 
 tain parts of France and Italy, had seriously been entertained by 
 Napoleon, while some partial attempts were also made to carry 
 it into execution. In spite of such experience and such evidence, 
 there are persons, as in all points of physic there have ever been, 
 who assert that the cultivation of rice is not unwholesome, and 
 that in Italy especially, it is not a source of Malaria. What ans- 
 wer can be made to assertions in the face of all evidence ? what 
 but that silence with which we receive the similar assertions of 
 those who maintain that plague and jail fever are not contagious. 
 The reason assigned by Zacchiroli will not at least be received 
 as proof ; when it is, that the air in such situations contains as 
 much oxygen as elsewhere. Could Eudiometry prove this, it 
 would prove much more that we should be well pleased to find 
 true ; and when he wishes similarly to prove that hemp ponds can- 
 not be pernicious, because the water contains tannin, we can only 
 smile at the all-sufficiency of a schoolboy's chemistry. Unques- 
 tionably, it may be admitted that rice grounds will vary in this ! 
 respect according to the nature of the soil, the mode of treatment, 
 the periods of inundation and drainage, and the pecularities of the 
 climate, so that it is even possible to conceive a case of excep- 
 tion ; but unless China can produce such, I know not that one 
 instance of exemption has yet been pointed out. 
 
 A similar assertion has been occasionally made respecting the 
 rice grounds of India, namely, that they do not produce fever, 
 
WHICH PRODUCE MALARIA. 27 
 
 and, consequently, do not generate Malaria ; it being further as- 
 serted that this is especially the fact in the peninsula. Indian 
 ] experience, it might be said, should be allowed to determine how 
 i far this is really true ; as no one ought to contradict such an as- 
 sertion from the theory or analogy. In the mean time, we may 
 at least be allowed to doubt; while if it should prove true, it is 
 but like so many other anomalies in this case, incapable of expla- 
 nation for want of more accurate knowledge of the necessary 
 facts. 
 
 It will be difficult, however, to admit the truth of an opinion 
 | which considers the rice grounds of Bengal or similar districts as 
 j not productive of remittent fever, until it is explained whence 
 j arise those fevers which so often rage in India, and of which the 
 |j year 1762 produced so destructive an instance ; since it was com- 
 jputed that, in this one season, the mortality included 30, 000 na- 
 tives and 800 Europeans in Bengal alone. Inundations of the 
 Ganges may be allowed their full share, and so, in many situations, 
 may jungles ; but if we exclude the rice cultivation, we shall 
 scarcely find sufficient causes for a mortality of this nature, of 
 which that country furnishes, and has furnished at all times, abun- 
 dant examples. 
 
 But were it even admitted that such a cultivation, in that 
 country, did not produce fevers, or rather, what is the more com- 
 mon assertion, that it does not produce intermittents, and there- 
 fore does not generate Malaria, it does not follow that it does not 
 generate Malaria productive of other diseases. Malaria does not 
 necessarily produce intermittent ; as the pure and simple, original 
 ague is rare in many of the most pestiferous parts of Europe ; 
 yet no one doubts its existence in those countries. And that it 
 produces glandular and visceral affections in France, in Sicily, in 
 Italy, all over Europe, without previous decided fever, or without 
 producing fevers at all, is as notorious as any thing in the whole 
 history of these diseases ; while there seems no reason whatever 
 to doubt that this is also a common occurrence in our own coun- 
 try. Hence, therefore, it might even be admitted, were itfneces- 
 sary, that from some unexplained peculiarity in the Malaria of 
 India, or of the climate, or of the state of constitution in the in- 
 dividuals, its action was often to generate glandular disease ra- 
 ther than pure fever, since the common endemic of India, hepa- 
 jtitis, is in reality the produce of its Malaria, and probably of that 
 : of its very marshes, meadows, and rice grounds. But it really 
 ! seems unnecessary to seek for explanations to answer what ap- 
 j pears the mere random assertion of a few individuals, biassed by 
 j some hypothesis, or unacquainted with the subject. 
 | Such is an enumeration, as far as it is here necessary, of the 
 jmost obvious and acknowledged species of soils or situations pro- 
 
28 SOILS AND SITUATIONS 
 
 ductive of Malaria. This is the ordinary view of the subject ' 
 which is taken by the people at large, wherever obvious circum- 
 stances have led them to feel an interest in it ; and I have, there- 
 fore, for the greater part, thought it superfluous to be minute, be- 
 cause that would have been to detail and to prove what is known 
 and admitted. If there are other kinds of land which, as modifi- 
 cations of these, must also be ranked among the admitted sources, 
 they are so much more nearly connected with those cases where 
 the production of Malaria is doubted or denied, that it seems most 
 convenient to pause here, and to class all the remaining causes 
 together in one chapter. And I hold it the more useful to adopt 
 such a division, because these remaining cases will thus attract 
 more attention than if they had been confounded with the broad- 
 er facts from which they essentially derive, and because my chief 
 object in this history of Malaria is to call the public attention to 
 the innumerable neglected or denied sources of that poison. 
 
 [ 
 
 CHAPTER IV. 
 
 Of the soils and situations less conspicuously productive of Mala- 
 ria, or as yet unsuspected of it. 
 
 To begin with the qualities of soil or situation which are least 
 likely to undergo dispute as to their power in producing Malaria, 
 or which are partially or tacitly acknowledged to possess this 
 property, I may commence from the fundamental point, the 
 marsh or swamp. 
 
 If it is acknowledged or proved that marsh or swamp, whether 
 fresh or salt, is generative of Malaria, it is also a very common 
 opinion that a certain extent of this soil, and, generally, a consi- 
 derable one, is necessary to the production of disease. This 
 is an error ; and it must "be classed among the dangerous ones, as 
 being productive of a false security. 
 
 A priori if a large tract of land in this particular condition pro- 
 duces a given quantity of Malaria, it is certain that this mass must 
 be an union of all the portions generated by its parts ; and if, as 
 is the fact, however vaguely stated, this poison is the chemical 
 produce of vegetables living or dead, acting on water, or acted on 
 
LESS SUSPECTED OP MALARIA. 29 
 
 >y it, then must every plant and fragment of a plant contribute 
 ta share of the deleterious substance. 
 
 j Now there is a certain analogy between Malaria and the mat- 
 ter of contagion, but on which it is unnecessary here to enter ; 
 md while we know that a quantity of contagion which is impon- 
 lerable, as it is insensible to every chemical test, and equally so 
 
 all our senses, is sufficient to produce its peculiar disease by 
 ts poisonous and chemical action on the body, we have no rea- 
 on to suppose that effects analagous may not be produced by the 
 hinutest portions of Malaria ; since, if we suppose any imagina- 
 
 le quantity applied, however large, it is still as insensible and as 
 jinponderable as the matters of contagion. It would bear that 
 jnalogy in this point, which it does to contagion in so many 
 (thers, if a small quantity were as efficacious a poison as a large 
 Jne ; and there are reasons for supposing, practically, that this is 
 fie fact, since it is matter of observation, that a, minute's expo- 
 sure to Malaria, a single inspiration probably, and of a poison 
 fmich must be far more diluted than contagions can ever be in 
 le same circumstances, is sufficient to excite its fever, and, very 
 otoriously, to re-excite it in those who are subject to that mor- 
 id sensibility derived from former or habitual fevers. And as 
 
 1 posteriori , any careful observer can confirm this last fact, it may 
 e concluded with as much security as such a case admits, that 
 fie quantity of Malaria necessary to produce its peculiar disease 
 1 diseases, is indefinably small, and probably extremely minute. 
 
 Could this admit of doubt, or should those who have made no 
 bservations, or who are incapable of observing, choose to deny 
 le well-known facts now alluded to as evidence, it would be 
 roved by the great distance to which Malaria travels through 
 le air without losing its poisonous quality. Not to dwell here 
 n examples which must be adduced hereafter, it is quite familiar 
 lat from any known and often very limited spot, this poison will 
 iroceed through the air, or on the winds, to distances of three or 
 >ur miles, exhibiting as much virulence as in its native marsh, 
 'his, to quote a familiar domestic example out of hundreds that 
 light be adduced, occurs on the hills of Kent, far from the 
 larshes of Erith, Northfleet, or Gravesend ; and it is easy to see 
 lat whatever was the body or quantity of Malaria in the origi- 
 al place of its production, or whatever portion of atmosphere it 
 pcupied over the few acres by which it was produced, it must 
 iten, in such a course, have been diluted to a degree so incom- 
 jrehensible, that while we can only wonder how it should exist 
 it all as a distinct substance, or a chemical compound, even more 
 mst we be surprised that it should be capable of producing ifa 
 eculiar diseases, with an activity as great, and often greater 
 lan it did at the very point of its birth place* 
 
30 SOILS AND SITUATIONS 
 
 In reality, this implies an activity on the part of Malaria, or, 
 what is the same thing, a power possessed by minute quantities of 
 this poison, to which that of all the contagions with which we 
 are acquainted bears not the most remote comparison ; since it is 
 notorious that the distance of but a few feet from the most active i 
 sources of these poisons, of the contagion of plague and of ty- i 
 phus, for example, is sufficient to render them innoxious, even ci 
 where the presence of a crowd of living bodies in the act of pro- c i 
 ducing them, assures us that the quantity generated must be con- i 
 siderable, and when we have also reason to believe, from the fa- 
 cility with which they unite to solid bodies so as to retain their . 
 properties, even for years, that they are not destroyed in the ca- 
 ses referred to, but merely diluted into inactivity. 
 
 The conclusion is obvious; and there is nothing in it which to 
 seems to admit of dispute, since it is almost a question of arith- 
 metic. If the produce of a hundred square feet, or acres, or of 
 any scale and number of parts, can, under a dilution of one thou- 
 sand or ten thousand times, excite disease, then must, in the in- 
 verse ratio, the produce of the one-thousandth or the ten thou- 
 sandth portion of that space be capable, before dilution, of pro- 
 ducing the same effects ; or a single blade of grass acting on 
 water (if this be the cause) may be as efficacious as an acre ; 
 supposing, of course, that it is actually applied to that part of the ; 
 body which can suffer from its action. 
 
 A marsh, therefore, as far as its essence consists in producing 
 Malaria, is not to be defined by space, or it does not demand ex- }: 
 tent ; and I must now show that it is not to be defined by its as- 
 pect, as that is commonly understood. It is essentially necessary 
 to analyze this subject to its very ultimate elements, before we 
 can form a right understanding respecting it. 
 
 In different climates, a marsh or swamp, other circumstances 
 being the same, may vary materially in its obvious aspect, accord- 
 ing to the nature of the plants which form its vegetation ; but as 
 no well founded suspicion has ever yet been entertained that 
 these have, according to their diverse qualities, any influence in 
 this matter, we must at present, perhaps, consider them as mere 
 vegetables, living or dead ; since we cannot prove that there is 
 even a difference in the action of the ligneous and the herbaceous 
 plants, other than what may depend on the relative facility of 
 their decomposition. 
 
 I do not, however, mean to prejudge this particular question, 
 or to suppose that the nature of the plants subjected to the action 
 which produces Malaria, does not affect either its virulence, or 
 its quantity, or the rapidity of its production ; or even, further, 
 that as there are diversities of contagion producing different dis- 
 eases, so there may not be differences in the varieties of Malaria, 
 
LESS SUSPECTED OP MALARIA. 31 
 
 Whether depending on this or any other cause, which influence 
 br direct the production of the several disorders which arise from 
 'his as a leading or generic source. So far from that, we might, 
 n the first place, very naturally infer, that as certain parts of any 
 vegetable are more prone than others to decomposition or putri- 
 [action, and as there are also some plants which run faster into 
 his state than others, so there might be important differences in 
 ihe quantity, quality, or rapidity of the poisonous produce, con- 
 nected as this is with the decomposition in question. 
 
 Thus, also, knowing, as we do, that the sensible gaseous pro- 
 duce of some plants in this state, is very different from that of 
 fkhers, and knowing also, from chemical analysis, that there are 
 pumerous and very striking differences in the elementary consti- 
 utions of plants, as there are in their actions on the animal body 
 k r hile in a living state, it would not be an irrational supposition 
 'hat the peculiar substance, Malaria, which results, as a genus, 
 Irom all vegetable decomposition, could be regulated, as to cer- 
 
 Pin variations, by the original chemical nature of the plant pro- 
 icing it ; or that, under this leading type, there were essential 
 prieties, poisons capable of producing different diseases or modi- 
 fccations of disease, just as different gases, distinguishable by their 
 Imells, if not as yet subjected to better and chemical tests, are 
 produced during the decomposition of such plants. 
 j Thus, to have recourse to illustration, might the cruciform 
 plants, or the tribe of fungi, produce a Malaria differing from that 
 poison as resulting from the gramineous ones, or the consequence 
 \( the putrifaction of seeds differ from that of leaves ; and thus 
 llso, while the putrifaction of capsicum produces a gas singularly 
 ptid and remarkable, as does that of the Bixa Orellana one not 
 jess offensive, if different, might the Malaria generated by these 
 fre attended with unusual virulence, or some other peculiarities, 
 f it is true that we have not as yet any decided evidence on this 
 ubject, there are not absolutely wanting some facts which ap- 
 i>ear to justify such a conjecture ; such as the peculiarly poison- 
 pus effects of flax and hemp in this state ; together with those of 
 ndigo, often observed, and those of coffee and other substances, 
 is supposed to have been ascertained at New York. 
 j Thus also has it been thought or said, that one cause of the su- 
 perior virulence of Malaria within the tropics, consisted in the 
 £reat proportion of astringent barks or vegetables which those re- 
 gions produce; though the reason assigned, namely, that they 
 Contain animal matter united to tannin, will scarcely be taken in 
 lieu of evidence. If some French writers have been at the trou- 
 ale of drawing up a sort of Flora of their own marshes with such 
 i view, it would be sufficiently easy to imitate them as to our own 
 jr any other country : but when they lay great stress on the influ- 
 
32 SOILS AND SITUATIONS 
 
 ence of narcotic vegetables, with not a little leaning also to a fan- 
 cifully threatening physiognomy in the plants of such soils, it 
 ought to be remembered that there is no great proportion of the 
 aquatic plants which is narcotic, and that as far as beauty is con- 
 cerned, there is nothing very unpromising in the Nymphoeas, the 
 Butomus, the Hottonia, the Hydrocharis, the Sagittaria, the Ra- 
 nunculus aquatillis, nor even in the Arundo, the Typha, the Scir- 
 pus, and many more, which form the predominant vegetation of 
 the most poisonous ditches and marshes. But, to pass over what 
 is fanciful, the subject is at least one of curiosity and interest : 
 nor only thus, since it might even become of value in the ques- 
 tion of prevention : but while nothing but possibilities can yet be 
 suggested, we must trust to future observation for the investi- 
 gation of this, among many other questions still involved in the 
 darkness which besets almost the whole of this important sub- 
 ject. 
 
 But to pass from this ; the essential character of all marshes 
 and swamps, as far as we yet can decide, is, that the land should 
 be partially inundated, that it should be dry in some places and 
 wet in others, or that pools and dry spots should be intermixed, 
 or that it should be boggy and soft from the mixtures of earths 
 and decayed vegetables with water, or that it should be subject 
 to peculiar alternations of moisture and dryness, sometimes 
 amounting to absolute inundation in the first case. 
 
 Now, in all this we see no apparent reason why the water 
 of the marsh should produce Malaria, because we do not find 
 that water produces it in other situations ; and as little have we 
 reason to suppose it the produce of earth and water mixed, or of 
 clay or mud ; since neither is it caused by such mixture where 
 vegetation, or vegetable matter is not present. Nor is it produc- 
 ed by the mixture of decomposed and subcarbonized vegetable 
 matter and water ; since it is notoriously not produced by dead 
 peaty bogs, or by peat which carries no vegetation. The pre- 
 sence of vegetables or vegetable matter, therefore, in some mode 
 or form, is necessary : while the conclusion has sometimes been, 
 that it is a production formed between the living vegetable and 
 water ; more generally, that it is generated between that and the 
 latter in some stage intermediate between life and absolute de- 
 composition; or, lastly, that it is the consequence of absolute pu- 
 trifaetion. 
 
 A qualifying remark is, however, here necessary on the subject 
 of peat. This is a substance which is not generated at all, above 
 a certain average temperature, on account of the rapidity with 
 which, in the higher ones, vegetable matters hasten to utter de- 
 composition. Hence it is limited, either to the colder climates 
 or to the more elevated regions in the hotter ones ; and though 
 
LESS SUSPECTED OF MALARIA. 33 
 
 not by any means confined to a temperature so low as to be in- 
 capable of producing Malaria, the greater and more numerous 
 ! tracts of peat land will be found to belong to countries or places 
 j where the production of this poison is checked for want of the 
 necessary heat. With this limitation, there will be no difficulty 
 Jin showing, as I shall very soon, that peat lands are not exempt 
 'from the production of Malaria ; though as no gas appears to be 
 I generated from this substance under the action of water, when 
 jjonce it is thoroughly formed, no such produce could be expected 
 from perfect peat ; while we must look for it in those cases where 
 the process is still incomplete, and cheifly in those where the ve- 
 getation is still going on, or where the whole series is in action, 
 | from the living vegetable to that completed peat where all de- 
 j composition seems at an end. With respect to the other remark, 
 i namely, that the presence of living vegetables is necessary, or 
 that Malaria is not formed during the putrifaction of that which' 
 is absolutely dead, or disintegrated, it will shortly appear that 
 this is an erroneous conclusion when too exclusively made, 
 though it may be viewed as a sort of rule ; yet under exceptions 
 in particular climates, that is^ in the colder ones, which almost 
 render it useless, and even false, as a rule of practice, or as a rule 
 connected with precaution. 
 
 Recurring now to the case of marshes, it remains therefore 
 first to inquire, whether this peculiar contact between a living 
 vegetable, or a vegetable in a state of incipient, or further de- 
 composition, and water, does not take place in many situations 
 that are not marshes, either in the popular, or in any, sense; and 
 if this can be shewn, there is one main datum obtained ; while> 
 if the former be also granted, namely, that space or bulk is not 
 necessary to the generation of Malaria capable of producing dis- 
 ease, we have all that is necessary to prove, a priori, that a thou- 
 sand places, hitherto unsuspected, are capable of exciting the dis- 
 orders of this great class ; while the proofs, a posteriori, will be 
 found in the evidences enumerated in the preceding chapter, or 
 may, for each place so inferred, be discovered by such examina- 
 tion into its local diseases. As to the case of absolute putrifac- 
 tion, or of decomposition, united to disintegration, I shall reserve 
 the inquiries to a separate chapter ; seeing that it comprises 
 i some facts and statements which have been subjects of doubt or 
 I dispute. 
 
 I Now, that this peculiar state of vegetation not only as to the 
 | appearance and character of the soil, but as to the mode of growth 
 | and death, and the very nature of the plants themselves, does oc- 
 cur in numerous situations that are not marshes, is the point to 
 be proved, and is a point indeed that will require no proof to al- 
 most the most superficial observers ; no proof assuredly to bota- 
 
34 SOILS AND SITUATIONS 
 
 nists, whatever it may to medical men ; not often even to the ob- 
 servant inhabitant of the country, whatever it may to the limited 
 man of towns and cities. If the botanist will recognize the spots 
 in question by the nature of the plants which attach themselves 
 to such soils, if the growth of an Iris, an Equisetum, a Hydroco- 
 tyle, points out to him what the farmer sees, though less acutely, 
 in tufts of rushes, or traces by the coarseness of the pasture or the 
 canker of a tree, it is the latter who will know every spot of land 
 about him which asks for drainage, where he to whom these pur- 
 suits are strange, will seek in vain, even should he, as a physician 
 be engaged in investigating this very question in a medical view. 
 So necessary is even such knowledge in a science scarcely to be 
 cultivated, and an art not to be practised effectually, without a 
 range of study far greater than is dreamt of by the mass of man- 
 kind, or than is often imagined even by physicians themselves. 
 •To such observers I must trust, to confirm facts that cannot be 
 transported to the tables of the sceptical or ignorant ; and I may 
 now proceed to specify the chief varieties of place or form in 
 which these circumstances occur, and thus to shew, under what 
 obscure, questioned, or unsuspected circumstances, Malaria, with 
 its consequent fevers and diseases, occur. 
 
 I have just observed that pure peaty bogs do not produce Ma- 
 laria ; and the same opinion is entertained in Scotland as to all 
 peat mosses, in whatever condition ; while the popular reason is 
 sought, since causes must always be found, in the imaginary anti- 
 septic qualities of peat, or peat water. As a general statement, 
 it is as far from being true, as the reason is fanciful and false. 
 Peat possesses no antiseptic qualities : it cannot itself putrify, be- 
 cause that progress has in reality been completed, if in a peculiar 
 manner : it is, thus far, what a vulgar phraseology in science used 
 to term a caput mortuum. The water of peat possesses no anti- 
 septic powers ; its contents, minute at all times, are merely hy- 
 drocarbonaceous compound, somewhat resembling bistre or resin. 
 The opinion is as puerile as the language is unmeaning and con- 
 fused. The climate of the great peat bogs of the north of our is- 
 land is one that has not energy enough to produce Malaria, from 
 any thing, except in very peculiar seasons ; while it is so far from 
 being proved that the intermittents of the fenny and peaty counties 
 of England are not actually generated in the very soil which is 
 supposed to be so adverse to them, that there can be no question 
 respecting their power in this respect, and as little respecting the 
 great extent and severity of the diseases produced by these very 
 lands. Further than this, 1 cannot confirm, by any very decided 
 fact, the power of a pure peaty bog in producing Malaria in our 
 own country, nor can it possibly be necessary : while I have little 
 doubt that observers possessed of means that I have not, will find 
 
LESS SUSPECTED OF MALARIA. 35 
 
 jno difficulty in establishing, by marked and decided facts, that, 
 finder a sufficient heat, they are, among us, as active in this evil 
 fas any other wet vegetating soils : and that they are so in Hol- 
 land, no one will question, whatever difficulty there may some- 
 times be in separating and discriminating the actual causes, in 
 jthose cases where land of this nature is intersected by drains or 
 Pitches. 
 
 It is also a popular opinion, that the rushy pools and petty 
 Iswamps so common in high moorlands, are innocent, or incapa- 
 jjble of producing Malaria. I know not why they should be more 
 Ibxempt than other marshy places, unless under a very high ele- 
 vation or a cold climate ; and that the fact is not so, has been 
 proved to my satisfaction, most convincingly, by many cases of 
 the occurrence of intermittents, even in Wales, and at considera- 
 ble elevations, in those very situations, and from these unques- 
 tionable causes ; while one instance is so remarkable as to be 
 worth quoting specifically, though I shall rarely indulge in a species 
 jof proof which must depend, as being a single fact, on the veracity 
 lof the narrator. In this instance, a considerable body of labourers 
 were employed in excavating a pond on a moor of this nature, 
 'situated about a thousand feet above the level of the sea ; and in 
 Ithe course of the work, within a very short time, nearly one half 
 were incapacitated by the ague. And if such rushy spots can, 
 because they are extensive, produce an extensive effect of this 
 kind, so, as will be more fully confirmed hereafter in parallel cases, 
 there is always cause for suspicion in the vicinity of even the 
 smallest fragments of such wet land, be the character what it 
 may. 
 
 There can be no doubt either, that the minute marshy or 
 swampy spots which occur occasionally in a thousand low situa- 
 tions, whether on commons, near woods, by road sides, or in in- 
 numerable other places where they scarcely or never attract no- 
 tice, are similarly productive of Malaria and disease ; though their 
 limited range of action generally renders their power in this man- 
 ner insensible, unless when houses happen to be erected in their 
 vicinity. Their characters as to vegetation are precisely the 
 | same as that of larger spots; while it would be abundantly easy 
 to quote examples of bad health, and even of severe fevers, pro- 
 | duced by them ; though difficult and tedious to refer to the exact 
 | places, obscure as they are innumerable, or to convince the in- 
 , credulous of the truth of the fact. As to the smaller spots of 
 ; w r ood, or coppice, or brushwoods, as yet little suspected in Eng- 
 j land, even where extensive, I need not recur to a subject on 
 j which I have said all that was necessary in a former chapter ; 
 I since in this case, as in that of marshy grounds, the possibility of 
 | a poisonous produce is not dependent on the extent : though, were 
 
36 SOILS AND SITUATIO 
 
 it possible to refer to the places, or could the enumeration which 
 has convinced myself, produce any greater conviction than the 
 general fact thus stated as operating on my own, it would be easy 
 enough to enumerate the specific examples on which this general 
 assertion is founded. 
 
 In how far meadows which cannot be called marshy are capa- 
 ble of producing Malaria, is an intricate and entangled question ; 
 partly on account of the difficulty of exactly limiting the term 
 meadow, or defining the degree of moisture, and partly because 
 they are so often intersected by drains and ditches, whieh may 
 sometimes be the generative sources, instead of the including land 
 itself. I cannot hope to clear this question by an exact definition ; 
 but taking the term in its usual lax sense, it appears unquestion- 
 able that there are many tracts of meadow, or of alluvial land, 
 not marshy, and often not intersected by ditches, at least in a con- 
 spicuous manner, which are the sources of Malaria all over Eu- 
 rope. 
 
 Such is the case with the alluvial tracts at the entrances, and 
 sometimes also at the exits of the lakes of Switzerland, and, 
 doubtless, elsewhere ; and such is the case all over France, in 
 the alluvial lands that border the great rivers, such as the Loire, 
 the Seine, and the Rhone ; and in places innumerable where there 
 is no proper marsh, nor even an approach to such a character, 
 to which the prevalent diseases can be attributed. Such also ap- 
 pears to be very frequently the fact in the interior of Italy ; 
 though I will not pretend to speak decidedly on any case which 
 1 have not personally examined ; knowing well, that neither or- 
 dinary travellers, nor even medical observers in general, deserve 
 much reliance on these subjects, inasmuch as they have not yet 
 seen the necessity of pursuing these observations with the neces- 
 sary accuracy. 
 
 I think, however, that the testimony of Volney on this point is 
 most satisfactory evidence to the purpose; because, while his 
 general accuracy as an observer is well known, and while, as not 
 being a physician or a theorist on this subject, he must be judged 
 unprejudiced, he appears to have bestowed a minute attention on 
 it during his travels in America. And that testimony is, that every 
 valley in the country which he visited, does produce the 
 fevers of Malaria; while, as he has minutely classed his causes, 
 so as to enumerate woods as well as marshes, and, besides all the 
 other better known sources, distinguishes even rivers, universally, 
 and, still more minutely, mill-ponds, there can be little doubt 
 that in thus enumerating valleys, he has done so as exclusive of 
 such specified sources, and therefore that, in these, he must 
 had an eye to the meadows alone by which they are characte- 
 rized, The same conclusion must be drawn from many of the 
 
LESS SUSPECTED OF MALARIA. 
 
 3? 
 
 rnicious tracts which occur on the shores of the Mediterranean, 
 fere, and in every country within this boundary, there is perhaps 
 ! no valley terminating in the sea, be it in Spain, Italy, Sicily* 
 | Greece, which is not a seat of Malaria ; while, though many of 
 ! the rivers which they include produce salt or fresh marshes, there 
 ; are also many where no proper marsh is formed, and where 
 j therefore the poison must be generated by the meadow lands; 
 by tracts which are also the seats of an active cultivation. 
 
 But, indeed, with respect to meadow lands, there is a circum- 
 stance of considerable importance to be considered, and which, 
 in fact, suffices to determine this question ; while if, in some cases, 
 it rather belongs to another branch of causes, it is too indetermi- 
 nate and graduating in its degrees, to be omitted in this place ; 
 since I am persuaded that it will be found the very common cause 
 i of the Malaria and disease produced by the lands of this class. 
 I In the extreme cases, it is inundation and subsequent drying, fal- 
 | ling therefore to be considered again elsewhere ; in others, it is 
 that drying during spring and summer, which follows the moist 
 or wet condition of such meadow lands, as they are left by the 
 winter rains. Instances of this, in all its degrees, abound every 
 where : but as one established example is enough, I may point 
 out the lands about Fontainebleau at the junction of the Yonne 
 and the Seine, notorious for the " Fievre du pays ;" so injurious, 
 that few escape fever or intermittent over a considerable tract, 
 while it is a pure example, inasmuch as there is nothing else pre- 
 sent ; nothing but that drying of moist meadows, whether previ- 
 ously inundated or otherwise wetted in winter, which takes place 
 under the summer heats. How extensively this cause operates 
 as to meadow lands in all cases, be their characters what they 
 may, I need not add : and I may therefore safely conclude, that 
 wherever the heat of the climate is sufficient, such tracts will be 
 among the most common causes of disease. 
 
 But whatever particular causes may exist in any specific case, 
 the mere fact that such tracts of meadow are productive of Malaria, 
 is, sufficient to operate as a caution respecting them, whether in 
 the choice of habitations, or in occasional residence during the 
 seasons in which that poison is called into action. 
 
 To what extent and in what places, similar land produces Ma 
 laria in England, will be best judged of by those whose local 
 j opportunities give them the means of ascertaining where the dis- 
 ; eases arising from this cause exist. But that this fact does occur, 
 ! and frequently, admits of no doubt; while 1 should find no difficulty 
 jhere, as in every other case which I have described, in proving 
 jit most extensively, by details, details of disease and enumeration 
 j of places, derived from personal observation or unquestionable 
 I authority : that authority also being peculiarly valuable, as being, 
 I F 
 
38 SOILS AND SITUATIONS 
 
 in almost every case, a mere report of the occurrence or preva- 
 lence of autumnal fevers in certain places, while the cause was 
 unsuspected. But it is evident that such a proceeding would 
 double the bulk of a volume, which it is most desirable to keep 
 within moderate bounds. A very few notices only of this nature 
 are admissible. 
 
 If some of the great tracts of meadow land in this country have I 
 once been marshes, and have been recovered to their present 
 condition by drainage, it is very certain that there are many of 
 them which are now purely meadows, without the least remains 
 of the marshy character; while some are even as dry as the ordi- 
 nary lower lands of the plains and vallies. And yet, that these 
 do produce the diseases of Malaria, is familiar to every one's ex- 
 perience ; though, in enumerating some of the instances, I cannot' 
 pretend to say that the cause may not, sometimes, lie rather in 
 the ditches than in the meadow itself. 
 
 This is true of the meadows which border the Thames, not 
 only beneath London and through their whole extent, but above 
 it; which, though often retaining the name of marshes, because 
 once marshy, are now as dry as the common meadow lands of 
 inland vallies and plains. It appears to be the fact also in many 
 parts of Cambridgeshire and Essex, and, among others, in the 
 vicinity of Waltham Abbey ; as it also is in Kent in the isle of 
 Thanet, in Somersetshire, in Lancashire, in Huntingdonshire, and 
 far more commonly indeed than it is necessary or convenient to 
 enumerate. Thus it also was, even in the Carse of Gowrie in 
 Scotland, until that great tract of alluvial meadow was brought 
 into universal cultivation ; and this may perhaps serve to prove 
 that the meadow land itself, and not the ditches, was the cause, 
 because the latter remain, while the grass has been succeeded by 
 almost universal crops of grain. And it will be found, in confir- 
 mation of this, in France and in Flanders, and probably far widei 
 than I now know, that where tracts bordering the same river, or 
 in any other respect exactly similar, whether in soil or situation, 
 are respectively, cultivated with grain or kept in grass, there the 
 production of fever or of Malaria is correspondent ; occupying 
 the uncultivated lands so as to produce what is popularly called 
 thefievre dupays, as if it was a necessary part of the order oi 
 things, and flying from those that have been ploughed for a grain 
 cultivation. 
 
 How the two facts, relatively, that is, a grain cultivation or 
 pasture, act in this case, it ought to be almost superfluous to say: 
 since the former husbandry will be commonly adopted whenever 
 the meadow can be maintained in such a state of drainage as tc 
 fit it for the plough, while a condemnation to pasture is also, in 
 itself, almost evidence of wet land. But I must here also add. 
 
LESS SUSPECTED OF MALARIA. 39 
 
 what T am obliged to remark elsewhere, that the mere act of 
 ploughing, with the crops and processes which follow it, produce 
 a very different effect as to the natural moisture of the soil, from 
 that which must occur under a dense covering of luxuriant grass. 
 
 If, in these instances, I have chiefly had in view the flat mea- 
 dow lands on alluvial soils, which, whether they have ever been 
 marshes or not, generally occupy the bottoms of vallies and the 
 margins of rivers, the same is not less true of upland meadows, 
 and even of perpetual pastures on the declivities of hills ; of all 
 meadow or pasture land, be its situation what it may, which is 
 retentive of moisture, or which the winter leaves poachy and soft 
 in spring, as it is thus rendered so again by the first autumnal 
 rains. If I could confirm this by specific facts, it would be even 
 more inconvenient, from the difficulty of reference to such spots ; 
 and I shall, therefore, content myself with suggesting to those 
 who, in the country, wheresoever, observe the fevers of autumn 
 to occur or prevail, to examine the land around, and to see whe- 
 ther, in the absence of more obvious causes, this one is not pre- 
 sent. They may thus convince themselves as I could not so rea- 
 dily convince them ; since they may be assured, as I hope to prove 
 satisfactorily hereafter, that some such cause is always the cause 
 of these fevers, and that all the others so often resorted to, are 
 imaginary ; while it is also fully time for them to understand that 
 such fevers are not contagious ; are not typhus. To proceed to 
 other causes. 
 
 It is not only a popular but a rooted opinion in England, that 
 there can be no Malaria produced near a running river or stream 
 of any nature ; an error, beyond doubt, and one, of which the 
 consequences may be, and are occasionally, serious. 
 
 With respect to the rapid streams of mountainous or elevated 
 countries, it is not probable that they are ever the causes of such 
 diseases ;. yet, in France, this opinion is held respecting all the 
 rivers at least that intersect the flatter lands. In a work so po- 
 pular, and, in this sense, vulgar, as the Letters of Madame Cam- 
 pan, this opinion is expressed in very strong language. And it is 
 apparently the result of a wide experience in France, though 
 there are doubtless cases where the inclosed meadow may be the 
 cause of what is attributed to the river banks. As to America, 
 w r e have the very strong and decisive testimony of Volney, the 
 accuracy of whose observations can seldom be questioned, that 
 every river in that country which he visited, whether rapid or 
 stagnant, produces Malaria and fevers. How frequently the same 
 opinion prevails in Italy, cannot fail to be known to the numerous 
 travellers in that country. 
 
 That the same should occur in tide rivers, such as the Thames, 
 would be a natural expectation, from the margin which is thus 
 
40 
 
 SOILS AND SITUATIONS 
 
 exposed under all the worst circumstances that belong to marshy 
 lands. And that it is the fact with regard to the Thames, I for- 
 merly noticed ; always providing a saving clause against cavils 
 from the vicinity of ditches or undrained^pots, as already remark- 
 ed. And if the same effect should occur in any river subject to 
 alternations of altitude from floods, or from ordinary increase 
 and decrease, as is remarkably the case with the Loire, it cannot 
 be a matter of surprise, because the deserted margin, or the bank 
 which is alternately wetted and dried is, in many cases, precisely 
 a marsh, in as far as we can conjecture what are the circum- 
 stances in this which do produce Malaria. Where, under such 
 circumstances as this, the exposure of mud is the consequence, it 
 forms a case which will come under examination hereafter. 
 
 If indeed any argument were wanted further, to prove that the 
 perpetual flow of fresh water, or the alternate rise and fall of the 
 tide so as to cover twice in the day a tract of the nature in ques- 
 tion, were not remedies or preventives against the production of 
 Malaria, it is amply demonstrated, and in a thousand places, in 
 the intertropical or hot climates, as I formerly suggested when 
 speaking of salt marshes. One or other of these is the condition 
 of those rivers, the character of which will be understood by all 
 who know the nature of such regions, when I call them Mangrove 
 rivers, let the woody vegetation or jungle consist of what it may : ; 
 and similar tracts of mangrove, or of other jungle or thicket, oc- 
 cur almost every where in those countries, which, if they do not 
 give passage to a river, are perpetually washed by the clear green 
 sea. Yet no one needs be told, that of all pestiferous soils or 
 tracts, none exceed these in destructiveness ; the Malaria being 
 never absent from the margins of such a river, even when steadi- 
 ly full, and appearing at the ebb tide, in the other kind of situa- 
 tions, almost at the very moment the ground emerges from the 
 water ; a fact amply and bitterly ascertained in our naval service, 
 everywhere. 
 
 Whatever doubts may still exist as to rivers in general in our 
 own country, in this case, there is no reason whatever to doubt 
 that such streams as the Ouse, the Lee, and all others flowing 
 with similar difficulty through fertile meadows and with a flat 
 vegetable margin, are productive of Malaria, because the diseases 
 which attend it are Gommon in all those situations. And, a priori, 
 we ought to form this conclusion, because the margins of suchi 
 streams in particular, are in every sense marshes. And abundant 
 facts, falling under my own observation, have shown that such 
 diseases as I have formerly adduced in proof of Malaria, exist 
 habitually and endemically on the borders of similar streams, of 
 even the smallest size; on those, for example, which flow almost 
 like artificial canals, through shaven lawns that border them with 
 
LESS SUSPECTED OP MALARIA. 41 
 
 i thin and grassy margin. Here indeed, in England, popular 
 opinion decides that no such disease can be generated where 
 ivvater flows, even should it flow through a pond ; but it is one of 
 the cases where popular opinion is popular ignorance or preju- 
 dice ; as it is sufficient for any careful observer to investigate such 
 Istreams and the state of the inhabitants near them, in any part of 
 England where they exist, to be convinced that the fact is as I 
 fiave here stated it. That any one should study to introduce 
 ^uch ornaments into his grounds where they do not already exist, 
 jor select them as places for the formation of pleasure grounds 
 £ind the sites of houses, is one of those pernicious errors which 
 lit is a part of the object of this essay to remove. 
 
 If, in this case, and also in others, I have often comparatively 
 eglected foreign countries, and entirely omitted the tropical and 
 istant climates, to dwell on our own, it is partly because this 
 essay is intended chiefly for our own countrymen, partly because, 
 with respect to other countries, the information to be procured is 
 (not sufficiently accurate ; and also because, as to the tropical cli- 
 mates, I can add nothing from personal observation and could on- 
 ly repeat what is already known to those who have attended to 
 this subject, or may be found in books, if with some difficulty, 
 and in the form of casual remarks, by those who are desirous of 
 studying it. 
 
 A canal, partaking partly of the nature of a sluggish river, and 
 partly of that of a stagnant pool, should natutally be esteemed a 
 probable source of Malaria ; because its margin possesses or may 
 possess, all the essential qualities of a marsh, as a diminution of 
 its waters may expose mud impregnated with vegetable matter. 
 This, in fact, is the point which we must always have in view ; 
 it is the analysis of the whole question. If it is not putrifying 
 mud, it is the marshy spot, the peculiar vegetation, or death of 
 vegetation, carried on at a certain point of vacillation between 
 earth and water, which is the generative cause ; and while this 
 may exist in a hundred different characters of ground or situation, 
 and while further it is not essential that bulk or space should be 
 present, it is easy to see that the business of investigation is, in 
 reality, reduced to a very simple principle ; for those at least 
 who are gifted with the powers of observation and generaliza- 
 tion. Let this fact be ascertained by a due examination of any 
 jspot, and the probability, at least, of Malaria is established : let 
 jit further be ascertained that certain diseases do belong to those 
 isituations, taking care also to prove that they are endemic or lo- 
 jcal, and the fact of its production is determined. That such con- 
 | fined spots do not act far beyond their immediate limits, that they 
 do not produce the same wide effects of disease as extensive 
 I marshy tracts, does not prove that they are not seats of Malaria. 
 
42 SOILS AND SITUATIONS 
 
 That which is originally but small in quantity, may, by being 
 transported even to a short distance, be diluted to nothing, or to 
 absolute inactivity ; while further, in all such cases, it will de- 
 pend on many collateral circumstances whether the poison which 
 they produce shall extend to any marked or notable distance, or 
 not. This is the common and constant error, whence the perni- 
 cious nature of such confined spots, be their characters what they 
 may, is overlooked, or denied. We are not to expect that a pool 
 of a few square yards is to cause fevers throughout a whole coun- 
 try, while also it may be so situated as never, or rarely, to be ap- 
 proached. But if it can affect its immediate neighbours, or ex- 
 cite but one fever in the course of years, the fact is as fully proved 
 as it is of the Pontine marshes. 
 
 To recur to the facts in absolute evidence respecting the nox- : 
 ious powers of canals, it is sufficient to revert to Holland, respect- 
 ing which I know not that there is any dispute. The canals of 
 Batavia, in a far worse climate, are still more notorious. As to 
 the few canals of Italy and France, lying as they so often do in . 
 districts of which the atmosphere is almost an entire mass of Ma- 
 laria, it must, in those cases, be fruitless to inquire what share 
 their banks or bulwarks possess in its production. The facts, as 
 far as they are known to me, are not pure enough to ground an 
 evidence on from observation, and we must be content with the 
 general reasoning a priori. If however the canals of France 
 shall be held authority for England, or even for Europe in gene- 
 ral, we have the authority of Monfalcon for their pernicious na- 
 ture ; since he enumerates them, generally, all through France, 
 as sources of Malaria ; not apparently deeming it necessary to ad- 
 duce such special evidence as I have been obliged to seek for, 
 since not encountering the same incredulity. 
 
 In our own country, if I have not, personally, been able to pro- 
 duce absolute evidence of the existence of the appropriate ende-: 
 mics in the vicinity of canals, I attribute it solely to want of 
 means for sufficient personal observation. I have little doubt that 
 the fact will be found such ; but must be content to point out to 
 others who may have opportunities, an inquiry into this part of: 
 the subject. 
 
 Next to canals, I may rank ditches and drains, already noticed 
 as probable causes of the production of Malaria ; and since theys 
 possess every property of a marsh, and in the very worst form, it 
 seems unnecessary to dwell long on a cause so obvious. What 
 limitations may be required to this as a general rule, are also too 
 obvious to require more than the barest notice ; as we can have 
 no reason to expect Malaria in the comparatively clean ditches 
 of upland grounds, where neither the drain itself nor its vegeta- 
 tion possesses the marshy character. 
 
u 
 
 LESS SUSPECTED OF MALARIA. 43 
 
 But if facts should be required respecting the pernicious effects 
 ditches or drains, Walcheren itself seems to furnish unexcep- 
 tionable evidence ; since the soil itself is sandy, being a mixture 
 iof clay and sand : and it appears to be from the drains chiefly, a 
 few pools being also present, that its most pestiferous air is pro- 
 duced. That, in the Campagna of Rome, which is also a dry 
 (soil, the Malaria seems similarly to be produced by the drains, is 
 a remark which I shall have occasion to make in another place. 
 jl know not indeed why there should be any reason to question 
 jthe fact at large, nor, unless from decided proofs of innoxious- 
 Iness, to deny it of any particular case ; since the chemical condi- 
 tion of a drain is so often that of a marsh. It is only for those to 
 idoubt this, and much more which I have here attempted to prove, 
 !kvho are guided by words, and to whom the connection between 
 Jthe two sounds, marsh, and ague, is exclusive as it is all-sufficient : 
 [unable to generalize the cause, as unaccustomed to view any 
 jthing in its principles. Or, otherwise, these statements are dis- 
 puted by those persons who conceive that an injury is inflicted on 
 them by endeavours to enlighten them ; incapable of pardoning 
 even him who would confer on them a benefit, when, before re- 
 ceiving that, a tacit confession of previous ignorance is necessary. 
 jit is the man who persists in eating the wrong end of his aspara- 
 gus. 
 
 Yet further, where medical men doubt or deny in these cases, 
 entraining with them, very naturally, the general mass, it often 
 arises from that inveterate error which I cannot point out too of- 
 ten, so essential is it that it should be remedied ; namely, the per- 
 petual seeking after ague as the sole proof of Malaria, and the as 
 perpetual forgetting, or not perceiving, that the fevers of sum- 
 mer which they persist in calling typhus, are the produce of the 
 very circumstances in question. Should it be doubted that such 
 iis the general feeling among our own physicians, as among the 
 Ipeople, I could prove it, as far at least as a single authority, on 
 jjboth sides, of the highest character, can prove any thing, by ad- 
 ducing the two greatest names in our own country, each in his 
 Ijrespective department, in proof of this. A sense of propriety, of 
 Iwhich no one will question the necessity, prevents me from nam- 
 ling those personages, as I must, for the same reasons, suppress 
 jeven the name of the place in question. All that I can venture 
 jito say is, that after a demonstration of the most palpable nature, 
 jit was merely admitted that the fetid mud thrown out in clearing 
 Jtjthis spot might indeed be unhealthy, and should be " corrected 
 P e*|by quicklime," but that quoad marsh or stagnant water, there 
 was no hazard, and that the fevers generated every autumn in its 
 vicinity were not its produce, but common typhus. 
 
 While on the subject of drains, I must now also inquire respect- 
 
t I SOILS AND SITUATIONS 
 
 ing the drains of towns or houses, in which, whether open or close, 
 is no living vegetation; a subject of some obscurity, and on 
 which there is a great deficiency of absolute evidence. There is, 
 I need not say, a general impression, I might perhaps safely add, 
 a general experience, of their insalubrity ; in proof of which I 
 might refer to the municipal reports and reforms of towns and 
 cities beyond enumeration, as I might, very especially, refer to 
 the history of the improvements of our own capital, and the cor- 
 respondent increase of its health. The question is, whether these 
 receptacles produce Malaria and the diseases arising from it, or 
 whether that which they have been esteemed to produce is ty- 
 phus, or disease of an analogous character. There is abundance 
 of general statements which would indicate that the former is the 
 fact, but there are also, as might be expected, not wanting many 
 which would show the reverse ; a natural enough consequence 
 of the universal and long continued carelessness in distinguishing 
 between marsh fever and contagious fever. I find one however 
 which is decisive, and which seems to me quite sufficient in itself 
 to establish the former opinion, or to prove that the diseases thus 
 produced are the diseases of Malaria, This is, that in the Salpe- 
 triere at Paris, intermittents were common among the residents 
 confined there, and that the Malaria having been suspected to en- 
 ter the house from the drains, the disease was, at once and for 
 ever, removed by making alterations in them. 
 
 Nor, on general principles, is there any reason to doubt that 
 this must be true, while it offers the readiest explanation of the 
 experienced insalubrity of such receptacles. A large proportion 
 of the contents must always consist of vegetable matter ; and it 
 is shown elsewhere, that hemp, flax, indigo, coffee, and so forth, 
 in a state of putrifaction or something analogous, do produce 
 Malaria, independently of any vegetation. And that the fevers 
 resulting from drains do occur in summer and autumn, or at those 
 seasons when Malaria is generated from all its other foci, seems 
 to present a further confirmation of their nature and causes, since 
 typhus, it is well known, is limited to no season, and is indeed, in 
 many towns, most frequent in winter. 
 
 Such appears to me the conclusion to be drawn as to this sub- 
 ject. I do not always expect to convince others by the facts that 
 have convinced myself; but that must not prevent me from add- 
 ing, that in a house well known to me, where intermittent fever 
 was perpetually brought on in an occasional visitor of considera- 
 ble susceptibility, as it had been, on former occasions, in another 
 person of the same constitution, and during a long course of years 
 no cause could be assigned but the passage of a sewer beneath the 
 house, or the existence of a well, since both were suspected : and 
 that in another similar case, the recurrence of an intermittent, 
 
LESS SUSPECTED OF MALARIA. 45 
 
 long cured, seemed as decidedly to have been caused by the ca- 
 sual inundation of a cellar. Should the absence of vegetation be 
 here held an objection, the fact that it can be produced by the 
 exposure of damp and naked ground, is put out of doubt by a 
 fact related by a physician and an author, whose name has es- 
 caped me, occurring in the West Indies ; where, on the removal 
 of some stores which had for some time covered a piece of ground, 
 I and on exposing it to the light, an immediate and severe fever 
 among the workmen was the consequence. 
 
 But before quitting this particular class of stagnant waters, I 
 must notice one case which seems important as illustrating the 
 general principle, as it indeed is with a view to sanitary measures, 
 although the exact circumstance has almost ceased to exist in 
 England, or occurs now but in a few places. The castle of Fla- 
 mandville, near Gueliette, in Normandy, is situated on the high 
 lands where no endemics of this class are known ; but, being sur- 
 rounded by a moat, has, for generations, been noted for the bad 
 health and destruction of its inhabitants ; while it may be partly 
 accidental as connected with this, that the original family has at 
 length been entirely exterminated, undergoing, as is well remem- 
 bered in the neighbourhood, that gradual diminution of powers, 
 both of mind and body, which is so conspicuous in the Orlean- 
 nais, and in every part of France, in fact, where Malaria is per- 
 petual. 
 
 It is not unlikely that, to similar causes, we must often attri- 
 bute the mortality of the besieged in the castles of the feudal 
 times, knowing, as we do, that fevers and dysenteries were the 
 causes of all this loss of life. Medical men indeed, often, or ge- 
 nerally, attribute this to want of provisions, water, and so forth ; 
 and, as constantly, have considered these fevers as the contagious 
 typhus, or the fever produced by confined human effluvia. 
 
 This error, which I can never omit to notice when opportuni- 
 ty offers, that of mistaking remittent fever for typhus, an error so 
 universal that we trace it through almost every medical work, 
 and so common, even to this hour, as to be committed every day 
 by nine-tenths of practitioners, or more, is one which, while it 
 confuses the whole history of endemic, as well as of epidemic fe- 
 vers, has also produced a train of incalculable evHs, in the cure, 
 jwith even far deeper and wider ones in the business of preven- 
 tion. If medical history is full of glaring examples of this in our 
 lown day, so it is from similarly false views that we must now 
 jread with distrust, almost all that is recorded of the diseases of ar- 
 mies in ancient times, and very much of what belongs to modern 
 warfare under the same head. Hence, we cannot fail to suspect 
 |that the mortality to which I am here alluding, arose from the 
 causes that I have stated, assisted, as is invariably the case, by 
 
 G 
 
|6 SOILS AND SITUATIONS 
 
 the various collateral evils which attended both the besiegers 
 and the besieged, though we cannot very properly dispute with- 
 out facts more particular. But while it is not very obvious why 
 typhus should be generated out of the habits of a baronial castle, 
 where ever} r defender was almost for ever in the air, it is abun- 
 dantly easy to understand how remittent and dysentery might 
 arise from confinement within a ditch, aided perhaps by scanty 
 food. This is very nearly the recent case of the Penitentiary, so 
 long and so improperly the subject of controversy ; a case in 
 which not the slightest doubt ought for a moment to have existed, 
 either with respect to the cause or the disease, and where a re- 
 medy was sought by letting in that Malaria, which it should have 
 been the object to exclude, or else destroy, as far as possible, af- 
 ter an admission that could not be prevented. 
 
 And further, this view is confirmed by the analogous conse- 
 quences occurring to the besieged, and very frequently also to the 
 besiegers, in the case of modern fortifications. There is often 
 the same bad or scanty food, with similar fatigue and exposure in 
 the night as well as in the day ; while the works to be defended 
 are either surrounded by water, or, if the ditch be not wet, it is 
 seldom truly dry in those flat countries which are the most fre- 
 quent seats of fortified towns. And, in fact, even in peace, these 
 fortified places are very generally unhealthy, and productive of 
 the diseases of Malaria, as will be discovered on inquiry by any 
 who will be at the trouble of making it; while it is scarcely less 
 easy to ascertain, that, in most of these cases, the focus of the dis- 
 ease is in the ditch, and that the attack, or the fever, falls first on 
 the sentries who mount the night guards on the ravelins or the 
 glacis. This was notorious in Malta during our first occupation 
 of the works of Valeria, whatever the fact may be at present ; 
 though, in that particular case, as I shall hereafter attempt to ex- 
 plain, it is not certain that the ditch actually produced the Mala 
 ria which occupied it, and which affected the guards of those par- ^ 
 ticular posts so remarkably. But almost every fortification in 
 Flanders and Holland, and many in France, will afford evidence 
 enough of this nature ; as will Portsmouth also, in our own coun- 
 try, if I am not very much mistaken, even at present, though much 
 improved of late by means which I need not here detail. 
 
 To mention but two facts more, one of which particularly 
 proves the insalubrity of such works, it had been suspected that 
 the fevers at Bourg en Bresse, which, down to the middle of the 
 last century, had so tormented the inhabitants that half of them 
 were incapacitated for a third of the year, arose from the ditches 
 of its fortifications. These were consequently filled up, with the 
 result of effecting an entire change, in the disappearance of those 
 fevers. Lastly, it had been observed that at Havre de Grace, 
 
LESS SUSPECTED OF MALARIA. 47 
 
 the soldiers were seized with headach and giddiness within five 
 minutes after approaching the ditch, with the usual consequences 
 of fever, and that fever, of course, of a violent character. Whe- 
 ther this fortification has been reformed or not, I am ignorant, 
 but it is a case strongly in point ; while it also serves to prove, 
 incidentally, that a very brief exposure to this poison is sufficient 
 to produce the effects, and further, that the effect immediately 
 follows the application. 
 
 The last class of situations requiring notice, includes all still or 
 stagnant waters, from the largest lake to the smallest pond ; and 
 it will be found to comprise an immense number of localities in 
 our own country, respecting which also there is perhaps less pop- 
 ular suspicion than with regard to any other species of ground 
 generative of Malaria. 
 
 A lake cannot, it may be thought, be otherwise noxious in this 
 sense, than as it may contain marshy margins, or be skirted by the 
 wet alluvial tracts, formerly noticed, and generally found at the 
 entrances of its streams ; and I need not therefore dwell minutely 
 on that particular subject. 
 
 But it requires observation to detect a thing even so obvious 
 as this ought to be. The general purity of the waters of a lake, 
 added to its brilliancy, often to its romantic or picturesque cha- 
 racter, and not a little aided by poetical feelings or metaphysical 
 prejudices, commonly remove all suspicion of this nature ; and, 
 after the physician interested in investigating this subject, it is per- 
 haps the painter, or the geologist alone, who will discover, or 
 even see, along the shores of such a piece of water, the particu- 
 lar ground which is a cause of suspicion or a source of disease. 
 Whatever, with other views, these latter may detect, it is not the 
 splendour of the scenery, the limpid purity of the waters, nor 
 even the rocky precipices or pebbled shores, that will be, to the 
 former, a warranty of health and security, if he finds these limpid 
 waters encroaching occasionally on a meadow, or the gravelly 
 margin shallowed by accumulating reeds and water plants, or the 
 water lily reposing in some creek, undisturbed by the waves. 
 Here, he will see reasons for suspicion, even in the most roman- 
 tic lakes of an alpine region; and should they lie in a warm cli- 
 mate, his suspicions will be too commonly justified. 
 
 And they will also be confirmed by a great mass of facts deriv- 
 ed from the Lakes of Switzerland and Italy ; there being abun- 
 dant records even of severe epidemics in these countries and in 
 such situations ; independently of the ordinary endemics, and of 
 a permanent bad state of health in the inhabitants, which can 
 scarcely fail to be known, even to general travellers in those coun- 
 tries, of any observation. How the fact stands in our own coun- 
 try in this particular case, I am unable to say ; while., though such 
 
48 SOILS AND SITUATIONS 
 
 effects might possibly be found in Westmoreland and Cumber- 
 land, they could scarcely be expected in Scotland, where our 
 chief lakes lie, .on account of the low temperature of the cli- 
 mate. 
 
 When a lake lies in a flat country, a case of which our own 
 Whittlesea mere offers an example, it is much more easy to un- 
 derstand how it should be a source of Malaria, without further 
 explanation ; since not merely its margins, but much of the sur- 
 rounding land, must possess those qualities which are pernicious. 
 Such is the natural history of a large portion of Hungary, noted 
 for its insalubrity, and such also is that of many considerable 
 tracts in France, often referred to in this essay on account of 
 their highly pestiferous nature ; the waters in question, of differ- 
 ent sizes, amounting often to many hundreds within a small space, 
 and including therefore what must be called pools, while they 
 form the basis of a very profitable inland fishery, regularly farmed 
 and cultivated. Respecting these, I must add, that they are 
 there esteemed fully as poisonous as marshes ; a fact inferred from 
 comparing two unhealthy and extensive districts of these differ- 
 ent characters. 
 
 But it must also be said in explanation, (a view which is im- 
 portant, as it concerns all waters of this nature, even to pools,) 
 that in France, it is supposed that the Malaria is not solely pro- 
 duced by the vegetating marsh, but is disengaged from the mud 
 which the summer leaves dry, (a fact which I must notice again) 
 and that it also escapes from the bottom and through the water, 
 accompanying the air which is so notedly extricated in those 
 cases. And in confirmation of this, it is said, that while such 
 pools retain a considerable depth of water, or whenever their 
 banks are steep, no Malaria is produced, but that it appears in 
 the reverse cases, or, either on the diminution of the water in 
 depth, or on its retiring from theshores. The same facts, I should 
 observe, have often also been noticed in the West Indies ; while 
 a very strong case, illustrating this particular cause, is stated by 
 Senac, in France, where, in a town previously unaffected by fe- 
 vers, a violent epidemic was produced, in consequence of an un- 
 usual evaporation which exposed a large portion of the bottom of 
 a lake. From these facts it is wi obvious inference, that in warm 
 climates, at least, whatever may be the case in our own, tranquil 
 or stagnant water is unsafe in any form, and that a vegetating 
 margin is not rigidly necessary to its pernicious qualities ; though 
 it cannot be doubted that the evil is materially diminished by 
 cutting off this additional source of Malaria. 
 
 With respect to other still or stagnant waters, including mill- 
 dams on all scales, from some hundred acres to a few square 
 yards, and comprising also fish-ponds, artificial and ornamental 
 
LESS SUSPECTED OP MALARIA. 49 
 
 lakes and canals, together with casual pools formed in uneven 
 ground, or, as near London, in old gravel pits, there seems, inde- 
 pendently of their sizes, but one marked difference among them ; 
 and that is, whether they do or do not transmit a running stream, 
 and in what quantity as it relates to the renovation of the mass 
 of water which they include. In mill-dams, this is a fundamental 
 property, though the renovation varies in almost every instance. 
 It is generally the case also with ornamental waters and fish- 
 ponds, but seldom or never happens with the remainder of the 
 pools classed under this head. 
 
 Now here, as in the case of rivers, it is a popular conviction 
 that there can be no " danger," as it is expressed, when there is 
 a running stream, or a renovation of the water ; an error of the 
 greatest importance, as I shall shortly demonstrate. If, among 
 the general mass, this is a mere opinion of rote, the usual ground 
 of belief with the vulgar, there are not wanting among others, 
 reasons, such as they are, for this piece of philosophy. All the 
 danger apprehended is invariably from stagnant, absolutely stag- 
 nant and putrescent water ; or it is considered that either the 
 smell is the criterion of the hazard, or that the poison and the 
 smell are one thing. Thus, a water covered with duckweed, or 
 crowded with potomogetons, nymphasas, and other floating and 
 absolutely aquatic plants, is the exclusive object of terror; 
 while no fear or suspicion is ever entertained respecting a limpid 
 and apparently pure water, whether at rest in a green lawn, or 
 gliding quietly along its grassy and poachy margin. 
 
 If I once thought that a heresy so wicked and an alarm so ab- 
 surd as I have experienced the contrary belief to be, was my own 
 exclusively, it was for want of reading ; and I am now most glad 
 to find myself supported by Monfalcon, though how far he also 
 may be accused of belonging to the class of terrorists, I cannot 
 pretend to foresee. " Pieces d'eau d'agrement ;" " lacs artifi- 
 ciels," such are conspicuously in his catalogue of evils ; and with 
 such aid I may therefore boldly continue to defend my own opi- 
 nions, while 1 would gladly not have been able to produce the 
 proofs which, even now, I shall leave to be conjectured. If he 
 refers pointedly to the artificial water of Chantilly, as the source 
 of frequent and serious epidemics, so does another authority, 
 D'Audebert, ascribe some peculiarly severe intermittents occur- 
 ring in his experience, to a similar piece of water, and a similar 
 cause. On the subject of such ornamental pieces of water, how- 
 ever small, 1 could not indeed wish for stronger testimony than 
 that which respects what is called the " canal" at Versailles, al- 
 most a mere fish-pond ; and which, like the similar "piece d'agre- 
 ment" at Chantilly, is noted for producing summer fevers and in- 
 termittents ; so noted as to have been quoted by Monfalcon as a 
 
50 SOILS AND SITUATIONS 
 
 special example of the pestiferous nature of such spots ; while I 
 have seen the very effect produced, and instantaneously, on an 
 
 English visitor to that "Tiber" of the ancient monarchy, and that 
 effect being as inveterate a tertian as I ever witnessed. 
 
 \Ve have not enough of pure experience yet, to decide whether 
 water, in all cases, emitting smell simply from decaying plants 
 immersed in it, or water confined by walls or clean earthen banks, 
 and producing purely aquatic or floating plants, does produce Ma- 
 laria, independently of the exposure of its mud, or of a diminu- 
 tion which allows the air to escape from the bottom. It would, 
 however, be very surprising were such water innoxious ; since it 
 ought to be indifferent whether the vegetable decomposition is 
 produced under this peculiar mode, or in the plants while attach- 
 ed to the land. It would not therefore be safe to conclude, that 
 by walling in the water of a pond, and thus destroying the vegeta- 
 ting margin, we have ensured safety, though we have excluded 
 one source of • the poison; and hence I should not consider this 
 alteration in the canal of St. James's park a complete remedy, 
 although my own proposal ; since it is notorious for the abundant 
 produce of aquatic plants, causing, in autumn, an even insuffera- 
 ble stench. All I can say is, that if in its present condition, 
 abounding in both causes of Malaria, it does not generate fevers, 
 it is the only exception in the whole world, at least wherever the 
 climate equals that of England ; a fact undoubtedly which ought 
 to be a source of great self-congratulation. Whether the pond in 
 St. James's square also, forming so refreshing a receptacle for its 
 statue, claims the same English exemption or not, must be deci- 
 ded by Monfalcon ; as I am not courageous enough to think that 
 such an Italian substance as Malaria can exist in the center of the 
 English capital. But to finish with this particular question, we 
 do know, from ample experience, that Malaria occurs in abun- 
 dance when there is no smell and no putrescence, and that the 
 process of vegetable putrefaction, in the ordinary sense of that 
 term, is not necessary to its production. There is good reason 
 therefore why we should shun the vicinity of putrescent and ve- 
 getating waters, but there is infinite hazard in rendering this doc- 
 trine and this terror exclusive. 
 
 To prove that mill-dams, though transmitting large streams, 
 ought to be injurious, from the frequently marshy nature of their 
 margins, would be to repeat what has been said before, respect- 
 ing the priori proofs on this subject in general ; and by the same 
 laws we may judge of the other kinds of still water included un- 
 der this head. To prove it by facts, to prove the actual produc- 
 tion of Malaria, in some place or other, and even in a vast num- 
 ber of places, by every kind of pool or still water here mentioned, 
 would be abundantly easy to myself, and will be scarcely less so 
 
LESS SUSPECTED OF MALARIA. 51 
 
 to any one who will inquire respecting the endemic diseases of 
 those who reside in such vicinities. 1 might here easily fill some 
 pages with local instances ; but I shall be content with naming a 
 very few ; selecting such as are either known to others as well as 
 myself, or that may easily be verified by any one still inclined to 
 doubt. That similar condemnation has been passed universally 
 on mill-ponds or dams in America, by Volney, may perhaps as- 
 sist in satisfying those to whom the authority of a strong name is 
 necessary, or who receive with faith from a stranger and a fo- 
 reign country, what they are unwilling to believe from him who 
 prophesies where he is known. 
 
 About the iron district of Glamorganshire, there are numerous 
 large mill-dams constructed for the supply of machinery, and 
 there is not one of these, in the lower grounds, which is not noto- 
 riously attended by the endemic ill-health of all the immediate re- 
 sidents and visitants, consisting in the diseases already mentioned ; 
 of which, in consequence of some peculiarities which I do not 
 pretend to explain, the Neuralgia of the face is extremely com- 
 mon. And as the surrounding country is high and hilly, and sin- 
 gularly healthy, as are the people in general, from their state of 
 industry and opulence, these local exceptions are the more con- 
 spicuous ; being indeed so remarkable as to have attracted the at- 
 tention of the people themselves to the causes. And when I 
 point out the pernicious nature of such receptacles of water, so 
 "very little suspected in our own country, and least of all likely to 
 be suspected, even by medical men, when in a cold or elevated 
 district, I may, from the report of an intelligent medical friend, 
 name, specifically, the village of Hirwain, in this county, where, 
 about four years ago, one-sixth of the inhabitants were affected 
 by intermittent at the same time, and from this very cause. 
 
 These are waters on a large scale, and from the size of their 
 streams, rapidly renovated ; offering a sufficient proof that such 
 renovation is of no value. In truth, there is no reason why it 
 should be so ; since were this as rapid as possible, the pond 
 "would even then be but a river, and it has been shown that ri- 
 vers so circumstanced are common sources of Malaria and disease. 
 A mill-dam at Southend, near Lewisham, affords another example 
 of a similar nature, on a small scale, and within the reach of easy 
 verification ; while it is also an instance applicable to fish-ponds 
 and other kinds of still water similarly circumstanced. Here, the 
 poorer inhabitants in particular, are notedly subject to intermit- 
 tent as well as autumnal fever, while they bear marks of glandu- 
 lar visceral affections, and are reported to die of the consequences 
 of those disorders. To have seen the fit of intermittent invaria- 
 bly produced in a susceptible individual by an approach to this 
 pond, hundreds of times, and always within a stated distance of 
 
52 SOILS AND SITUATIONS 
 
 time from the approximation, completes an evidence which can- 
 not be controverted. 
 
 And if my chief reason for pointing out this otherwise insignifi- 
 cant spot, is the facility of examination which it offers to the in- 
 habitants of London, it will be useful to notice here the whole 
 valley of the Ravensburn, with the communicating low lands, in- 
 eluding the villages of Lee and Lewisham,as affording examples, 
 within reach, of the greater number of the less obvious class of 
 situations producing Malaria, which I have been attempting to 
 describe. The use of such examples is, that as there is a pecu- 
 liar physiognomy, if it may so be called, attached to all such 
 places, the power of distinguishing that is more easily acquired 
 by a single example than by pages of description. 
 
 I may add here another instance, from the mill dam of a paper 
 mill in Hertfordshire ; after the formation of which, the workmen 
 became subject in a most serious degree, to remittent fevers, which 
 were, before that, unknown ; and as the ground in this particular 
 instance resembled that of an ornamental park, as did the water 
 itself, it may suffice to prove what I have advanced on that par- 
 ticular subject ; although it would be easy to confirm this by an- 
 alogous instances adduced from many of the dressed pleasure 
 grounds ornamented by water, which skirt the Thames, near 
 Walton and Chertsey, and which occur also in a hundred other 
 places : the produce of a well known improving gardener, or else 
 of his progeny; to the demerits of whom, as the sources of an 
 endemic disease of English landscape, far, very far yet from be- 
 ing extirpated, an eruptive contagion blotting our fair island, it is 
 no small addition that they have, in founding ponds which their 
 vanity mistook for rivers, and in converting rivers into Dutch 
 canals, brought the intermittent to our doors under cover of the 
 breeze of the violet, and formed pest houses of fever where we 
 study to retire for coolness from the heats of the autumn. This 
 is to manufacture a Batavia, in defiance of nature ; to court dis- 
 ease through deformity and expense ; the evil less, it is true, but 
 of the same kind, and incurred as certainly. 
 
 Here is another case in point: for I believe that it is only by 
 such specific facts, that popular conviction, less amenable to ge- 
 neralizations, Will ever be produced. In a high and formerly 
 healthy part of Hampshire, the name of which, for the reasons 
 often here assigned, I must reserve, a clear and quick stream was 
 dammed not long ago, both for ornament and use. The immedi- 
 ate consequence was seen in the production of evening mists be- 
 fore unknown. That mist indeed is not in itself Malaria, but it 
 is a very common attendant, as it is a conductor; while it is always 
 a suspicious circumstance, for obvious reasons. But the proof 
 was completed by the production of fevers, and in autumn; as 
 
LESS SUSPECTED OP MALARIA. 53 
 
 unknown before as the mists. A French or an Italian physician 
 would be at no loss here in deciding; but the English apothecary, 
 having no term but typhus for a destructive fever, decides accor- 
 dingly ; never questioning himself as to the origin of the contagion 
 of which he dreams, nor ever recollecting to wonder why it 
 should not spread to the attendants, when the patient is covered 
 with petechias ; and thus the public goes on, creating more mill 
 dams, more fish-ponds, more fictitious rivers after the models of 
 Brown, and more fevers. To proceed. 
 
 In one instance, while I need not quote the particular place, 
 the recurrence of an intermittent fever in a susceptible subject 
 was caused repeatedly, by merely entering a garden containing a 
 I pond of the fashion of King William's day, dedicated to gold fishes 
 i and river gods. And that the same effect is produced, by similar 
 J ponds or canals in these and similar situations, in many of the 
 ornamental grounds and gardens of rural habitations, particularly 
 in the flatter tracts of England, is a fact which has at length been 
 confirmed to me by many individuals who had at first rejected the 
 suggestion: such persons now recollecting what had not originally 
 struck them, that their families were always unhealthy, and, in 
 particular, that their servants were so, while residing at their 
 country houses, though free from such complaints in their town 
 residences. And when, during the last summer in particular, it 
 has been notorious, that not only numerous individuals, but entire 
 families have experienced fever under change of temporary resi- 
 dence, sometimes in their own country houses, at others in the 
 several watering places situated amid the circumstances here 
 pointed out as suspicious, there seems nothing wanting to pro- 
 duce conviction ; since most assuredly these fevers were not the 
 contagious typhus. 
 
 On the subject of the smallest, and the least suspected, perhaps, 
 of all kinds of ponds, I shall commence by quoting one instance, 
 because it was notorious to the medical establishment of Wool- 
 wich in those days, and because there are, doubtless, officers and 
 surgeons both, alive still to confirm it. This was a pond occu- 
 pying an old gravel pit on the common, close to a house belong- 
 ing to the late Dr. Hutton, and occupied by General Stehelin ; its 
 whole extent being but a few square yards. It was remarked, 
 for a long course of years, that the inhabitants of this house suf- 
 fered under perpetual agues ; and it was not until this pond was 
 destroyed by the alteration of that common, that the disease dis- 
 appeared, and forever. 
 
 This is perhaps sufficient proof as to this class of stagnant wa» 
 ters ; but, if I mistake not, it will be found that the occurrence 
 of ague and fever together with other ill health, in numerous pla- 
 ces where the gravel pits of commons are filled with water, is the 
 
 H 
 
54 SOILS AND SITUATIONS 
 
 consequence of this very cause, and that in reality, these situations 
 about London, and elsewhere also, so often selected on account 
 of the imagined wholesomeness of their gravelly soils, are very 
 general, and not less unsuspected, causes of ill health : of those 
 obscure and teazing disorders already mentioned which are known 
 by this vague term, and further, of positive fevers and intermit- 
 tents. And it was not only from reflecting on that case at Wool- 
 wich common, but on other analogous ones, that I originally 
 gave the opinion, that provided the vicinity is sufficiently near, 
 and other conditions favourable, there is no spot of water, or, 
 what is the fact, of marshy vegetation, so small, as not to be capa- 
 ble of producing Malaria and disease. 1 have shown already, that in 
 cases of distant transportation, the poison must be highly diluted, 
 and, therefore also, must be applied in a very small quantity ; 
 and on every chemical, even arithmetical, principle, it must be 
 indifferent whether that small portion which acts, is part of a large 
 mass, or is, itself, the whole. If it be a grain weight, or a cubic 
 inch, out often thousand, which is applied, or if there be but 
 one grain or one inch generated, and the whole is called into ac- 
 tion, the effects must be the same, chemically : while this is a 
 chemical operation, and the last case the case in question. 
 
 To the inhabitants of London, I might easily point out numer- 
 ous places, even in their own vicinity, offering illustrations of 
 these several causes of Malaria, and more ; as it would be abun- 
 dantly easy also to indicate them in all the southern and flatter 
 counties ; while an inquirer can always satisfy himself as to the 
 facts, by simply inquiring among medical men, respecting, in 
 particular, their autumnal practice. To the same readers, and 
 for the same purpose, an easy verification, I might, but for ob- 
 vious reasons, have quoted a well known house, peculiarly situ- 
 ated in the neighbourhood of London, as having been a most 
 noted focus of ague to almost every one of its inhabitants during 
 a long course of years. And I intended to quote it as an instance 
 of Malaria produced by some small ponds with a grassy margin, 
 used for watering cattle ; were there not some imperfection in 
 this case, arising from its position as to the meadows of the 
 Thames ; though I am still inclined to seek the cause in these 
 ponds, as the corresponding and neighbouring houses in the same 
 vicinity, and with the same aspect, do not suffer in the same 
 manner. 
 
 I must here add a remark on the production of Malaria, which, 
 if not rigidly belonging to the present enumeration, could not 
 well have found a place any where else, while it is too impor- 
 tant to be omitted. If the occurrence has chiefly been noticed in 
 other countries, there is not wanting evidence respecting it in our 
 own; while the more generally the fact is known, the more will 
 
LESS SUSPECTED OF MALARIA. 55 
 
 it probably be confirmed : as happens in every case of this nature, 
 where, until the exact cause of such a disease is pointed out, it 
 continues to be viewed as one of the inexplicable and necessary 
 accidents of life, or is perhaps attributed to some false or imagi- 
 nary cause. 
 
 This fact is, that fevers, and therefore it must be presumed 
 Malaria, are often produced, and frequently in great severity, 
 when pasture lands are for the first time broken up for cultivation. 
 The evidence as to this, is as abundant as it is unquestionable. 
 Volney points it out as almost invariable in America ; and so does 
 Rush, as I have noticed, particularly where woods have also 
 been cleared. In the West Indies, very generally, it has long 
 been known that this is a most dangerous operation, since it is the 
 almost universal experience of two centuries ; and Cassan de- 
 scribes it as sometimes producing fevers that resemble an absolute 
 plague ; the labourers even dying on the spot if they attempt to 
 remain at night on the ground which they have broken up in the 
 day. 
 
 Why this should be the fact, if it cannot be very precisely ex- 
 plained, is not at least more difficult than most of what else be- 
 longs to this subject ; since there is a quantity of vegetable mat- 
 ter killed, and therefore submitted to decomposition ; and it would 
 be well worth the trouble of those whose local situations give 
 them the means, to inquire whether this, and many other analo- 
 gous agricultural processes, now little suspected, are not causes 
 of the fevers which sometimes appear in rural situations in such 
 an inexplicable manner, when these cannot be better accounted 
 for by stagnant waters of various kinds, or by such neglected 
 spots as 1 have here been pointing out. The remark is of value, 
 be the solution what it may ; because the remedy will be found 
 in breaking up such lands in June, or in May, if the summer be 
 the necessary period, or, what is preferable, in the middle of 
 winter ; since the decomposition will then take place at a time in 
 which experience has shown that Malaria is scarcely generated 
 in our own country, nor indeed, generally, in Europe. In the 
 case of lands recently recovered by drainage, this precaution is 
 peculiarly deserving of attention, because in this case the danger 
 is greatest : and the same is equally true of woods, the mere fell- 
 ing of which sometimes disengages or produces Malaria, as is a 
 much more certain consequence where, as in America, and as I 
 have elsewhere noticed, these woods are broken up for cultiva- 
 tion. 
 
 On the question of drainage, there are also some remarkable 
 facts, which though nothing very definite can as yet be offered on 
 the subject, from want of sufficient observations, I must also no- 
 tice here, not very well knowing in what other place in this 
 
56 SOILS AND SITUATIONS 
 
 essay they could be introduced. The bare fact, as stated in the 
 simplest manner, is that lands subjected to drainage, and appa- 
 rently laid dry, sometimes even for the very purpose of subduing 
 or exterminating Malaria, have become even more noxious than 
 before ; or, that even where no previous diseases had existed in 
 the vicinity of such land, they had appeared after it had been 
 drained for the purposes of agriculture. Among other remarkable 
 instances, this appears to have been true, at different periods, of 
 the Campagna of Rome, as far as the facts can be ascertained by 
 comparing the different accounts of Italian writers ; while, in 
 speaking of that spot, I have been obliged to notice this circum- 
 stance, as it relates to the comparative condition of Rome in the 
 times of antiquity and in the present day. But among some more 
 pointed facts of this nature which admit of no dispute, such was ' i 
 the effect of draining the marsh of the Chartreuse near Bordeaux. { i 
 A succession of bad fevers, before unknown, commenced imme- 
 diately upon the drainage, showing themselves first in that part 
 of the town which lay nearest to the land reformed, and lasting 
 through many years ; proving so severe in 1 805, that twelve thou- 
 sand people were affected, out of whom three thousand died in 
 five months. 
 
 To explain why this should happen, in any particular case, 
 would require a precise knowledge of the individual circumstan- 
 ces belonging to each spot where it is said to have occurred ; as 
 it is probable that many of the cases would require distinct solu- 
 tions. At present, and in this general view, I can only suggest 
 a few of the probable causes ; while those who may have oppor- 
 tunities may possibly, not only be able to apply them, but also 
 discover others which, from want of experience, I am unable 
 even to conjecture. 
 
 It is not difficult to understand that a swamp in which the wate 
 is so deep as to impede the growth of as many plants as a drier 
 surface would carry, will produce proportionally less of the poi 
 son in question ; and that a similar diminution or under proportion 
 of Malaria will attend such a tract of land if it should contain 
 many pools or spots divested of all vegetation. In such a case 
 we can conceive a certain state of drainage, such as to increase 
 the vegetating surface, without being at the same time complete 
 enough to check the production of Malaria; or a small quantity 
 of poisonous marsh might thus become a large surface of wet and 
 noxious meadow land. 
 
 Thus also, it is not difficult to imagine how the drainage of a 
 lake attended by a noxious margin, might increase the extent of . 
 such a description of soil, though the water itself were diminished ', 
 or exterminated, and a considerable tract of drv land sained abo 
 to cultivation. 
 
LESS SUSPECTED OF MA.LARIA. 5' 
 
 I It is a much more delicate and difficult question, whether there 
 I is not also a certain state of moisture, much inferior to absolute 
 I wetness, which is more favourable to that peculiar vegetable de- 
 j composition whence Malaria is generated ; but while some facts 
 j seem to show that this is true, there is nothing sufficiently decisive 
 j to prove, what also we have not at present the means of render- 
 ing as probable as might be wished, from not knowing enough of 
 the process itself, and of the nature of this poisonous matter. 
 When it is asserted that land absolutely dry does generate Mala- 
 ria, as has been said of many places, it is necessary, before we 
 can admit this, to be very certain that, in these instances, it is 
 j not transported from some other place ; or that, in such dry land, 
 j there are not ditches and drains left from the operations by which 
 I it has been laid thus dry. In reality, as I have already remarked, 
 I it is from these poisonous repositories of a vegetation equally active 
 in growth and in decomposition, that the Malaria of drained mea- 
 dow lands seems to be very often produced ; while, if there are 
 I any other causes, they must he left for future enquiry. 
 
 Yet there is a tolerably obvious one, though how far it may 
 | have been applicable to any of the known cases I cannot conjec- 
 I ture ; and this is, the exposure of the mud of pools, or of that 
 bottom which was, before that, to whatever limited extent, and 
 however dispersedly, covered by water ; since this, as I shall soon 
 show more fully than I have yet done, is an ascertained cause of 
 Malaria. In such a case indeed, the evil might be expected to be 
 transitory, and to be limited perhaps to one season; though it is 
 not difficult also to see, that as such spots must be the most de- 
 pressed parts of the recovered land, they might easily, in succes- 
 sive winters, retain water, so as, again, on the recurrence of the 
 summer heats, to undergo the same pernicious condition. If 
 also, in such cases of drainage, the cultivation of any portions 
 should follow, it becomes evidently an example under the rule al- 
 ready discussed; according to which, lands newly broken up ge- 
 nerate the poison in question. 
 
 I shall now terminate these details, which I have nevertheless 
 abbreviated, perhaps injuriously, by the omission of innumerable 
 local facts and proofs, and of much that I might have included re- 
 specting foreign countries. Such minuteness would however find 
 a better place in a work on the geography of Malaria ; a work 
 than which there cannot be a much greater desideratum at pre- 
 sent in physic. Whatever detail I have already indulged in, I 
 cannot consider it greater than the importance of the subject de- 
 manded ; because it is only hy rendering the public aware of the 
 causes of their diseases, that they can be taught to eradicate, by 
 activity, and on principle, that which will otherwise only yield, 
 as it has already done to so great an extent, before the slow pro- 
 
58 SOILS AND SITUATIONS 
 
 gress of general intelligence and improvement, or else to avoid, 
 as far as possible, the causes of disease, where the soil itself is in- 
 curable or difficult of cure. But the value of such precautions, 
 like that of the present opinions, will not be appreciated till other 
 Views than the present ones are taken, of the causes of the com- 
 mon fevers of summer and autumn, or till physicians, if that shall 
 ever happen, coincide with myself in believing that the most fre- 
 quent, perhaps the general, sources of these among ourselves, and 
 especially in the country, are the soils and situations which I have 
 here described or noticed. It will indeed be a previously neces- 
 sary step, to distinguish between such fevers and contagious ones, 
 or between typhus and the fevers of Malaria; a distinction, how- 
 ever, which if as yet spreading but slowly in the public medical 
 mind, if indeed even that can be said, must at length become un- 
 derstood, when it will be acted on as mechanically as much else 
 has been in physic after labouring under the same difficulties ; 
 since it is not through reasoning, but from imitation, that know- 
 ledge is here spread, while in establishing a new opinion or fact, 
 chance or fortune must also coincide with the labour of the origi- 
 nal propounder. 
 
 If 1 have already noticed the general ill health and the various 
 disorders exclusive of mere intermittent?, which are the produce 
 of these neglected or unsuspected places, it will be of much more 
 general importance if it shall be established, as seems to myself 
 the fact, that all our common summer fevers are the produce of 
 unsuspected Malaria, and not, as is generally supposed, of mere 
 heat, or, when occurring in autumn, of some mystical and un- 
 known influence of the preceding summer, or, as is a common 
 opinion, somewhat better founded, of the effect of this on the bi- 
 liary system merely. And if, in the country, where it is much 
 easier to purify the evidence, and after many years of watchful- 
 ness in various districts and places, it has proved to my experi- 
 ence that such fevers prevail or predominate wherever there are 
 those obscure causes of Malaria which I have pointed out, (sup- 
 posing that more decided and acknowledged ones a^e absent,) 
 and that they can almost always, with care, be traced to some 
 such causes, while they scarcely if ever occur in places absolute- 
 ly free from such suspicion, I car not help thinking that it is a fact 
 which will be confirmed by the observations of others, when the 
 same attention shall be turned to the subject. To ascertain the 
 exact truth will be valuable ; because it will be a great step in 
 the prevention of evil that may at least be diminished, if not re- 
 moved. 
 
 It is a philosophical evil in the mean time, and will probably 
 long prove an obstacle to the inquiry after truth in this case, that 
 physicians have established so many doubtful or fanciful causes of 
 
LESS SUSPECTED OP MALARIA. 59 
 
 fever ; to discover or imagine any one of which is held sufficient, 
 even by those who inquire into causes, to satisfy the observer 
 and supersede all further questions. And if among such causes, 
 there are real ones, it is also too often forgotten that these are aux- 
 iliary or predisposing ones, not essential ; leading to errors even 
 more difficult to correct. In other departments, philosophy would 
 act more cautiously and more precisely : in some points, even 
 physic proceeds more philosophically. Malaria is a proved, de- 
 monstrated cause of one class of fever, as contagion is of another ; 
 and if in the latter case, we labour to discover the insidious or ob- 
 scure roads by which it has been communicated, so should it be 
 our object, equally, to seek for Malaria wherever it may lie hid, 
 and not to rest content with those vague and fanciful, or doubtful 
 causes of the fevers of this nature which are commonly received: 
 and for little other apparent reason than because our ponds and 
 ditches do not, like the marshes of Italy or the woods of Africa, 
 destroy their tens of thousands, or perhaps because of indolence 
 and habit, superadded to ignorance and want of reasoning. 
 
 If I have insinuated that there are tracts of country, places in 
 our own island, where fevers, that is to say, the fever under re- 
 view, in any of its forms, is unknown or nearly so, and if the 
 same is true of many districts in various parts of the continent, 
 even in countries where other tracts are notorious for such dis- 
 eases, it would not be so difficult as it would be tedious, to point 
 out, even now, the very places, to a considerable extent ; while 
 it would be found that these were dry and elevated lands under 
 a perfect natural drainage, or similar moorland or corn districts, 
 or peculiar situations near the sea, of the same character, or dis- 
 tricts uniting a particular distribution of the surface to a peculiar 
 nature of sub-soil, or general stratification, or rock ; well known 
 to the geologists of our island, as well as to agriculturalists, for 
 their singular freedom from water, and the reasons for which can 
 often be explained by the former. 
 
 And if, as is the fact, such tracts are exposed to the same heats 
 
 ) and the same vicissitudes of temperature as those in which these 
 
 I fevers occur or prevail, if the people are the same, and their oc- 
 
 cupations and modes of life similar, and if the only difference be, 
 
 as is the fact, the presence of water in some manner, and often 
 
 I very trivial in quantity and extent, while as little noticed or sus- 
 
 j pected as it is thus trivial, then have we reason to conclude, or 
 
 I at least to conjecture with a high degree of plausibility, that this y 
 
 j the only difference, is the cause of disease which we are in search 
 
 of: while that is confirmed by every circumstance relating to the 
 
 production of Malaria which has already passed under review. 
 
 If it would be tedious to point out the tracts of land to which I 
 
 am here alluding, it will also perhaps be much better to leave the 
 
60 SOILS AND SITUATIONS 
 
 inquiry to others, each for that division of country best known to 
 himself; while, with these hints, such an investigation will not 
 only be easy, but will produce to the investigator, a conviction 
 which could not be effected by any detail founded on my own 
 observations. 
 
 And if, on the great scale, or in the extreme cases, such as in 
 Holland, (where, to such records as that of Walcheren, or of 
 Sluys, in which, according to Lind, the Scotch regiment quartered 
 there buried its whole number in three years, hundreds of similar 
 examples might be added,) the average of life is proved, by the 
 tables of insurance and survivorship, as I shall hereafter show, to 
 be low to an appalling degree, it will not less, if less conspicuous- 
 ly, be found in our own island, that this average is exceedingly 
 unequal, and that, in every case where the fact has yet been ex- 
 amined, it is precisely in the dry situations which I have been de- 
 scribing that it is highest, while, reversely, it becomes gradually 
 lower as water, in almost any form, is present: almost emulating 
 Holland, and in a very obvious gradation, as we come down to 
 that state of the soil where Malaria and its diseases are no longer 
 a question of dispute. That our own tables have not yet been 
 corrected, as justice demands, by such considerations, is no proof 
 that the fact is not as I have here stated it ; as the carelessness 
 with which this subject has been hitherto treated, is well known 
 to those who have attended to political arithmetic ; while some 
 recent attempts at greater accuracy, proving also, as they do, the 
 increased public longevity, give hopes that the whole of the sub- 
 ject will, ere long, undergo that review which is so imperiously 
 called for. 
 
 If I feel while I write, what I have for so many years experi- 
 enced in personal discussion, that it is difficult or impossible to 
 convince the multitude, and even medical men, that in such cases 
 as those which I am now discussing, water, or a moist soil, can 
 produce disease and fever, or that it is in reality a source of Ma- 
 laria when in such trifling quantities, or under such common and 
 neglected circumstances, similar doubts, or repugnance, or igno- 
 rance, have prevailed at every period, from that at which the 
 evil was a maximum ; while every successive improvement or 
 drainage has produced that conviction to a more enlightened pos- 
 terity, which argument then, as now, would have failed to effect. 
 If, in the cases to which I allude, the evil should have even be- 
 come a minimum, which is not the fact, it would still be an evil, 
 while, in reality, it is not a small one ; and while the whole is but 
 a concatenated series, an affair of majusand minus, there is as lit- 
 tle reason why we should stop short of all that improvement 
 which is practicable, as there was for interrupting the chain at 
 any one point, and deciding that, there, in that proportion or that 
 
 : 
 
 EI 
 
 : 
 
LESS SUSPECTED OF MALARIA. 61 
 
 peculiar condition, water, or wet ground, had ceased to be per- 
 nicious. 
 
 With a view to this fact, this series of gradually diminishing 
 evil, of successive improvements in the condition of land, in our 
 own country, and also elsewhere, attended by a diminution of 
 diseases equally progressive and proportional, and therefore prov- 
 ing a gradual diminution in the generation of Malaria, it would 
 be neither unamusing nor uninstructive to trace the corresponding 
 progress of health and drainage ; while it would, however, occu- 
 py more space than I dare bestow on it, and since the truth of the 
 facts is too obvious to be disputed. A very few noted ones may, 
 however, be mentioned in illustration; while the success of that 
 j which has been done, though this can never again be obtained to 
 j the same extent, holds out encouragement to such further attempts 
 jas are yet wanting : the neglect of which is not justified by the 
 conviction that little remains comparatively to be effected, since 
 in the present state of society, a small quantity of endemic disease 
 is, for many obvious reasons, as great an evil as a much larger one 
 was when human life was of less comparative value, as implying 
 both less happiness and less utility, and held also under less se- 
 ll cure a tenure ; while it is not questioned that the protection of 
 I the public health, is not less the duty of an economist and a poli- 
 I; tician, than it is a duty of mere humanity. 
 
 It would require a long chapter to point out what has been 
 done in this respect, even over a small part of Europe : and even 
 a mere sketch respecting Holland would be one of no small 
 length. In France, similarly, it has been an object of unremitting 
 attention to the government, as it has occupied the exertions and 
 the funds of many private individuals; the public decrees to this 
 purpose commencing with Henry the fourth, and being repeated 
 under successive monarchs, down to Louis XVI. in 1791, and 
 subsequently, under Napoleon, in 1807, 1811, and 1817. The 
 great embankment of Rochelle is one of the most conspicuous of 
 these works ; and as a few other examples out of many, I may 
 name the drainage of the marsh of the Chartreuse at Bordeaux, 
 already noticed, the reformation of Montbrison in the Lyonnais, 
 once the very type of this pest, by filling its ditches and erecting 
 ! " boulevards," and the drainage of Chatillon in Burgundy ; an 
 j operation from which the population has doubled within thirty 
 : years. 
 
 Nor has Paris gained less than London in this respect, and by 
 | operations still more directly carried on with this very view ; 
 I since it must really be admitted, that it is to indirect means that 
 j we are indebted, not only in the capital, but almost ev.ery where 
 | else, for all that we have gained on this point : there having al- 
 ways prevailed among ourselves, that neglect, ignorance, incredu- 
 
62 SOILS AND SITUATIONS 
 
 lity, or contempt as to Malaria, which is even now so remarkable, 
 and which, at this very day, refuses to believe that it is a cause 
 of disease demanding and admitting correction. The history of 
 Italv on this subject has occupied volumes, and I must refer to 
 Prony and others for what it is impossible to quote: while it is 
 not perhaps the least instructive part of this history, that in con- 
 sequence of the suspension of the work which had been com- 
 menced under Napoleon in the Pontine marshes, the Malaria is 
 as virulent there as ever, though some land was rescued to agri- 
 culture. 
 
 On this point, the improvements of England in this respect have 
 been immense, almost even within our own memories ; undertaken, 
 it is true, chiefly with agricultural objects, yet marked by a con- 
 comitant disappearance of disease, which would seem almost in- 
 credible were it not well authenticated. We can scarcely indeed 
 look into English chronicle history without meeting the amplest 
 evidence of this ; and from such and similar records, Short, He- 
 berden, and others, have collected many striking facts, of which 
 I may here name a few. On Burnet's authority it rests, that in 
 the reign of Mary, the intermittent raged like a plague ; while we 
 have medical testimonies to the same purpose, in the writings of 
 Morton and Sydenham ; of whom, the former says that these dis- 
 eases were peculiarly destructive between 1658 and 1664. Be- 
 tween 1667 and 1692, two thousand persons appear to have died 
 in London of dysentery, from the evidence of the bills of mortal- 
 ity ; and it is a chance if, in the same extent of population, there 
 is one who thus dies at present. Even far later, that is, between 
 1720 and 1729, the whole nation, according to Dr. Short, was 
 " grievously afflicted with fevers of this nature ;" when, at present, 
 so rapid has the change been, we hear no longer of national epi- 
 demics ; though somewhat, as physicians know, must also be al- 
 lowed to other improvements in the modes of life. At present 
 also, an instance of death from mere intermittent is exceedingly 
 rare ; whereas, according to Short, among forty deaths from fe- 
 ver, between 1629 and 1636, one was the effect of ague ; while 
 in 1750, that proportion was not one in a thousand. That, as 
 far as London is concerned, this has been chiefly the effect of the 
 sewer drainage, is demonstrated ; though much must also be al- 
 lowed to similar operations in the flat lands to the eastward of 
 it, or generally along the banks of the river. When Sydenham 
 relates that the ague was frequently fatal in London in his own 
 day, he did not probably foresee that such an event, at the present 
 day, would be esteemed little better than marvellous; nor let us 
 persist in shutting our eyes to what yet remains to be done ; or, 
 whether from indolence or that pride which refuses to learn or 
 admit what it has not before known, refuse to exert ourselves in 
 
LESS SUSPECTED OF MALARIA. 63 
 
 exterminating the last remains of these causes of disease, as far at 
 least as they are within our power. 
 
 It has been suggested that a parliamentary inquiry into this sub- 
 ject might advantageously be adopted ; since it would be little 
 more than a sanitary measure, justified by other practices respect- 
 [ ing the drainage of lands in general, and by the laws respecting 
 imported contagion. It is probable that it would be attended 
 I with advantage ; while the inquiry needs not proceed to legisla- 
 tion. Such an inquiry is one of the most conspicuous and im- 
 pressive modes of calling the public attention to measures or con- 
 j duct in which their own welfare is concerned, and where, never- 
 : theless, it may not be expedient or easy for legislation to inter- 
 j fere. 
 
 As far also as the greater cases are concerned, or the extermi- 
 . nation of disease by the drainage and improvement of extensive 
 tracts of noxious land, (since with respect to the smaller pernici- 
 ous spots, no legislation, even in a despotic country, could easily 
 act,) I may borrow a remark from Italian, but chiefly from French, 
 writers ; though little applying to ourselves, among whom, while 
 so much has already been effected, it is not the usage of govern- 
 ment to perform any thing which can be executed by the com- 
 bined or private efforts of individuals ; being content, and judici- 
 ously, as the event has proved, with limiting its exertions to the 
 legal protection of all parties. The remark in question alludes to 
 the policy which wastes its means in foreign colonization, forget- 
 ting to extend by exertions and expence that would not be greater, 
 and often much less, the territory and the population which it 
 possesses at home ; suffering its own marshes to lie waste that it 
 may occupy foreign ones, and, what, above all, it seems ever to 
 have forgotten, forgetting that a population which is not healthy 
 is an evil and not an advantage, to the state as to the people 
 themselves ; and that if the wealth of the people is an object to 
 government, not less is it responsible for their health, since, with- 
 out this, even industry must be cramped, and misery become the 
 lot of those who demand and deserve from the state that hap- 
 piness which they know not how to attain, or cannot, by them- 
 selves, command. 
 
( &i ) 
 
 CHAPTER V. 
 
 Oil certain obscure and disputed cases relating to the production 
 
 of Malaria. 
 
 In this chapter I propose to notice some doubtful or disputed 
 facts, and some difficulties which attend this subject, that I might 
 not disturb the evidences as to what has been fully proved or in- 
 variably admitted. It is therefore a collection of unconnected 
 matters ; while, among them, the reader will, I think, perceive 
 that there are facts which ought not to have been disputed, as he 
 will also conjecture that what may appear obscure, has probably 
 been rendered so by ignorance, or else by inattention to the ne- 
 cessary particulars on the part of the reporters. 
 
 The condition of Egypt, whether in its state of quiescence or 
 inundation, the natural state of its Deltas, and that which takes 
 place on its inundation and drainage, are too well known to re- 
 quire description. Examing this case a priori^ we ought appa- 
 rently to decide that its moist delta should produce as destructive 
 a season of remittent as the worst parts of southern Africa, that 
 during the north winds it should even generate abundant inter- 
 mittent. We ought to decide that as its inundation is a swamp 
 of the worst kind, to the eye, and its drainage a marsh, the result 
 should be a wide devastation from all the usual diseases of tropi- 
 cal climates. There are fevers and dysenteries it is true, and 
 they appear, as might be expected, on the retiring of the water ; 
 but they seem to bear no proportion to what might be expected, 
 if indeed we may venture thus to judge from the general reports 
 of travellers who have not been physicians. It is probable that 
 the universal agriculture may assist in solving this difficulty ; for, 
 a3 before remarked, this is everywhere a remedy against Malaria, 
 as it ought to be on principle, by occupying, in a manner which 
 is much less pernicious or hazardous, land which would other- 
 wise produce an injurious vegetation. On the plague, I ought 
 not perhaps to indulge in any remarks; but no one can yet be- 
 lieve that this is the produce of a vegetable miasma, were it even 
 satisfactorily demonstrated to be the peculiar produce of Egypt, 
 when no disease produced by such miasma is known to be con- 
 tagious, and when this, in spite of recent party and paradox, is 
 one of the most actively contagious disorders existing. 
 
 Inasmuch as two difficulties of a similar nature are always pre- 
 ferable to one, in philosophy, as more likely to be under the gui- 
 
CASES OF MALARIA. 65 
 
 dance of some general and discoverable law, it will not be an 
 addition at least to that of Egypt, to say, that, by the reports of 
 travellers on certain parts of the East, the drainage of lands that 
 have undergone their annual inundation, is not invariably follow- 
 ed by the diseases that might be expected. There are few tra- 
 vellers whose observations are more apparently accurate, simply 
 expressed, and unbiassed by all previous views, than Captain 
 Hamilton, a century ago ; and of this nature is his report respect- 
 ing the periodically inundated lands of India east of Bengal. But 
 if this seemed at one time confirmed by the account of Captain 
 Symes respecting the rise and fall of the Trawaddy and of the lake 
 of Amarapoora, we have now reason to know that this country 
 claims no exemption from fevers ; and further knowledge will 
 probably prove that the same is true throughout Cambodia, Co- 
 chinchina, Siam, and all the countries of a similar character in 
 Eastern Asia. If a recent traveller has expressed his surprise at 
 the occurrence of fevers in the Maremma of Tuscany where the 
 land is not only free from lakes and rivers, but absolutely dry, and 
 if, building on this, he desires to represent the origin of Malaria 
 as involved in mystery, it will soon be obvious, if it is not so al- 
 ready, that this imaginary mystery is the produce of inattention or 
 ignorance. 
 
 And as the same answer will serve for all such cases, I need not 
 dwell on other parallel reports respecting other mysteries, similar 
 or analogous, which are to be found, not only in books, but in the 
 popular opinions, in our own country as elsewhere ; errors into 
 which physicians of high reputation, and of even the experience 
 ofLind, have fallen. Such errors have sometimes arisen from 
 neglecting some or other of the obscurer sources described in the 
 last chapter, and, at others, from ignorance respecting the mode 
 in which Malaria is propagated by the winds, and the distances 
 to which it is conveyed : a subject which will be fully discussed 
 in the seventh chapter. 
 
 In the mean time I may remark, in explanation of such mystery 
 that, in a case which will immediately come under review, Rome 
 receives its Malaria by a propagation of a peculiar nature ; as the 
 high lands of many places receive from the low grounds at hand, 
 what does not, comparatively, affect the inhabitants where it is 
 produced. And thus also, when it is a subject of common mar- 
 vel why ague should occur in London, it is forgotten that this city 
 is entangled in some measure among low meadow lands, and ex- 
 posed, in particular, as the last few years have proved, to the per- 
 nicious influence of those to the eastward. And if any one will 
 be at the trouble of noticing, in the neighbourhood of this never- 
 theless healthy city, such tracts of land, together with the petty 
 spots which, on the grounds here stated, and confirmed by the 
 
66 OBSCURE AND DISPUTED 
 
 French writers, can produce this poison, he will have little diffi- 
 culty in accounting for those fevers, in particular, which, in the 
 last summers, have been so prevalent, at least in its outskirts, at 
 different parts. 
 
 It is thus that I find the highest parts of Brittany to be subject 
 to inveterate ague, even on the summits of granite hills reported 
 to be dry land, as, for example, at Carhaix. Thus also was it re- 
 ported that certain hilly situations in Wales were productive of 
 agues, and, as was thought, without a cause : but the slender ob- 
 servation which detected that cause in this latter case, would pro- 
 bably have discovered it in the former, and in hundreds more, 
 equally objects of surprise or mystery. Let the ground be care- 
 fully examined, both on the spot, and in the neighbourhood, and 
 let the possible propagation by means of the winds be also traced | 
 by the rules deducible from what I shall hereafter say on that 
 subject, and it is probable that the far greater number of these 
 imaginary difficulties would no longer want their solutions. 
 
 Thus, also, had I not a repugnance to specify places and lands, : 
 where the owners might think themselves aggrieved by a public 
 notice of defects which may occasionally detract from the value, 
 whenever this subject shall become an object of general attention, 
 I might point out in Wiltshire, and not only there, but in counties 
 and places as little suspected, spots at a considerable elevation, 
 entirely free from marshes, or even the suspicion of an unhealthy 
 soil, and which are, nevertheless, annually, and within the last 
 hot summers, in particular, subject to severe fevers, and this amid 
 a rural and dispersed population. The resident apothecaries call 
 them, as usual, typhus fevers, and, naturally enough, are surprised 
 at their occurrence in such circumstances. The reader can now 
 I trust, give the just name to the fever; and, as to the cause, it 
 will be sufficient if he is now informed, that from the form of the 
 land and the nature of the subsoil, the pasture lands in question 
 are, although elevated, or rather truly hilly, so soft or wet as to 
 be constantly poached by the feet of the cattle. Here, there is 
 an unobserved, or an apparently mysterious cause, and I doubt 
 not, a very common one ; as little suspected as observed, while 
 the proof, as I have given it, is perfect, except to those who are 
 still in that state of ignorance or obstinacy which cannot under- 
 stand or will not believe in marsh fever; persons to whom a few 
 weeks of French or Italian experience would be of no small 
 utility. 
 
 But there is one mystery for which I can conjecture no solu- 
 tion, while it rests on great authorities, and while every imagina-<j 
 hie circumstance is present that ought to render the land in ques- 
 tion one of the most pestiferous spots under the sun. It is a col- 
 lection of jungles and woods and marshes and rivers and sea 
 
CASES OF MALARIA. 67 
 
 swamps, and it is a flat land under a tropical sun, and it is the 
 land of monsoons ; and yet it is a land where fevers are unknown. 
 And this land is our new settlement of Singapore. I dare not at- 
 tempt to controvert such testimony, and must try to believe what 
 I cannot understand: but others may, for aught I know, be in 
 clined to suspect that some favouritism, not perhaps inexplicable, 
 has dictated this report. 
 
 I may now dismiss a branch of this chapter, which I would 
 gladly have omitted altogether, had it not appeared absolutely ne- 
 cessary to notice what I believe to have much oftener arisen from 
 inattention, and from ignorance respecting the natural history of 
 Malaria, than from any radical difficulties inherent in the subject. 
 I may proceed to the consideration of the causes which have been 
 doubted, but on which, it is probable, no doubts ought longer to 
 exist. 
 
 Though it has generally been a popular opinion, that putrify- 
 ing vegetable matters, under whatever circumstances, generated 
 fevers, and therefore Malaria, while, as I formerly observed, the 
 very smell of such ^putrefaction was, and is yet, esteemed by the 
 vulgar to be the cause, or at least to be an essential circumstance, 
 many physicians had considered the presence of a living vegeta- 
 tion necessary ; while some were even inclined to deny that the 
 ordinary putrefaction of dead vegetable matter attended by stench 
 was capable of producing this poison. But the history of the re- 
 mittents of New York has decided this doubt ; that is, in as far as 
 it is decided that none of these fevers were the contagious, Bulam 
 disease ; since it is impossible to refuse assent to such observa- 
 tions as those of Rush and the other able physicians who were, 
 so long and so often, watchful spectators of the rise and progress 
 of this disease. Here, it was ascertained that the putrefaction of 
 coffee, pepper, potatoes, &c. were causes of the fever, or that they 
 actually generated the Malaria in question ; while the facts, as 
 stated, seem to confirm a suggestion which I formerly made, 
 namely, that it was not a matter of indifference in this case, what 
 was the nature of the plants growing in marshes, or in soils capa- 
 ble of producing this substance. 
 
 The fact, in a general view, is an important one, if it is thus 
 admitted to be proved ; as it betrays the existence of numerous, 
 local, and generally accidental, sources of Malaria ; not only ex- 
 plaining the occurrence of many single cases, but even account- 
 ing for occasional epidemic or endemic fevers ; and adding al- 
 so to this knowledge, a catalogue of precautions, so essential in 
 the prevention of those diseases. It would be tedious, and indeed 
 superfluous, to enumerate all the cases in common life where ve- 
 getable putrefaction may generate Malaria and fever ; but a few 
 examples of what is most common and most likely to be injurious, 
 
68 OBSCURE AND DISPUTED 
 
 or neglected, will be of use: while from those selected examples, 
 perhaps, a sufficient knowledge of the subject for all useful pur- 
 poses may be derived. 
 
 Of these, one of the most common in many parts of Europe, 
 and far from rare in our own country, is the process of soaking 
 flax and hemp ; the offensive nature of which is well known. 
 The proofs of the pernicious nature of these operations are so 
 numerous and decisive as to leave no ground for doubt, in spite 
 of the theoretically puerile objection of Zacchiroli which I had 
 occasion to quote formerly. Of pointed facts beyond number, 
 related both in France and Italy, we find in Lancisi, that numer- 
 ous severe epidemics in the latter country have been traced to 
 these operations, and, among the rest, a noted one at Ferentino, 
 and another at Orvieto which lasted many years. In the former 
 country, out of similarly numerous cases, severe intermittents 
 broke out in the plain of Forez in 1823, after October, (a very 
 rare occurrence,) and were traced to this cause ; and we have 
 the assurance of M. Bourges, that it is invariably pernicious, 
 while he describes one very marked case where fevers occurred 
 in a dry, sandy, and otherwise healthy and elevated situation, be- 
 ing regularly renewed with the steeping and drying of the hemp, 
 and disappearing when that season was over. 
 
 In Germany also, where this manufacture is extensively car- 
 ried on, it seems to have been most satisfactorily proved that 
 fevers, and of a very bad kind, are the result: a fact which, with 
 very many others, tends to establish the opinion elsewhere notic- 
 ed, that the severity or nature of the resulting fever, in whatever 
 way it may be influenced by climate and other causes, is probably 
 also dependent either on the nature of the particular Malaria, or 
 on the quantity in which it is applied. That, even in our own 
 country, some regulation of police is called for respecting this 
 subject, has often been said, and with reason ; since it is scarcely 
 amenable to the common law of nuisance, unless under that en- 
 gaging laxity which characterizes English Common Law ; and 
 if, as is decidedly said, the process in question can be much bet- 
 ter effected in running waters, and also without poisoning the 
 stream, although not so rapid 1 ^, there are at least many places 
 where this method might be sabstituted with a double advantage. 
 
 To the ascertained poisonous action of the refuse of the Indigo 
 manufactory, many more might easily be added, of a similar or 
 analogous nature ; but the general principle being admitted, there 
 will be no difficulty in applying it : while if an accuracy of ob- 
 servation which has never yet been exerted on this subject, any 
 more than on that of small spots of wet ground, shall become com- 
 mon, instead of our remaining satisfied with imaginary causes of 
 fever, it is probable that many very unsuspected cases of vegeta- 
 
CASES OP MALARIA. 69 
 
 ble putrefaction, such for example as even that of a garden dung- 
 hill, will be found to give rise to those disorders, of which the ori- 
 gin is at present so generally mysterious ; together with the con- 
 sequent advantage of prevention, in many instances. 
 
 It does not seem to have been thought that Malaria is generat- 
 ed in water casks, or by that action of water on mere wood, 
 which occurs in sea voyages, eliciting a well-known smell, and 
 producing hydrocarburetted gas; a process so long misunderstood, 
 even by chemistry, to its disgrace, and, even yet, not compre- 
 hended by those who are most interested in it ; who attribute to 
 the water what they should seek in the cask, and whose notions 
 as to the superiority of Thames water, are on a par with their 
 philosophy about Bristol water, and about all else which belongs 
 to this most simple subject This is a question which must re- 
 main for further inquiry ; while it must in the mean time be con- 
 j sidered a suspicious circumstance, and if so, applicable also on 
 shore in similar cases, or where rain water is kept in spoiled 
 casks. The suspicion arises chiefly from what I shall immedi- 
 ately point out as to bilge water, of which, in ordinary cases, the 
 cause is the same. ; while, in a chemical view, we cannot see 
 why there should be a difference, or why decomposing wood 
 should not generate Malaria as well as other decomposing vege- 
 table substances ; inasmuch as there is no steady and essential 
 difference between the vegetable elements in the case of wood 
 and of the other portions of a plant, or of herbaceous plants in 
 general; nor any apparent reason for doubting that the fragments 
 of wood are, in the tropical climates, as active in this mischief as 
 the leaves or other parts. 
 
 Whether, if even thus produced, it is capable of acting so as to 
 generate disease, is another question, and perhaps more compli- 
 cated than at first appears. Yet, if a brief exposure to the Mala- 
 ria of marshes can excite a fever, as 1 shall hereafter show that it 
 does, or if a small quantity of the poison, or a single inspiration, 
 is sufficient for this purpose, it is perfectly conceivable that the 
 air in question may similarly affect a person immediately exposed 
 to it by close communication with such a cask, whether at sea or 
 |on shore. 
 
 This is easy to understand ; but there is a difficult question 
 still remaining : and that is, whether the drinking of such water 
 can produce the same effect, or whether the Malaria, if it con- 
 tains Malaria, can act through the stomach as well as through the 
 .(lungs. It is the same question which relates to the use of bad 
 kvater in tropical climates, as it also involves the greater one, viz. 
 by what ways Malaria does or can enter the body ; and as 1 have 
 jjbeen compelled to examine these elsewhere, it is unnecessary to 
 speak further respecting this matter, at present. 
 
 K 
 
70 OBSCURE AND DISPUTED 
 
 But if the putrefaction of wood in water-casks at sea, though 
 not yet suspected of producing fever, can scarcely be deemed 
 innocent, the same suspicion attaches more strongly to the case 
 of bilge water ; very particularly when produced from the leakage 
 of sugar, where it is known to be highly offensive. It has not, 
 as far as I know, been ever demonstrated, nor indeed much sus- 
 pected, that the fevers of ships were produced from this cause ; 
 while, whenever fever does occur in such a situation, it is gene- 
 rally, or perhaps almost always, viewed as a typhus and a conta- 
 gious disease. The error itself is easy ; and while it is one also 
 strongly aided by prejudice and habit, it is plain that the remittent 
 might, as thus occurring, be so mistaken without any great stig- 
 ma on the discernment of the practitioner ; as it would be difficult 
 to ascertain that numerous cases of fever, breaking out in this 
 manner among a crowded crew, were not propagated from one 
 person to another. Yet the distinction is of great importance, 
 for many obvious reasons ; nor need I point out further to medi- 
 cal men, how necessary it is to ascertain what the truth actually 
 is on this point. To maintain, as there seems at present a ten- 
 dency to do, in a sect which appears to be now seeking notoriety 
 by parados, that there is no such thing as a contagious fever, is 
 assuredly to attempt to establish a most dangerous doctrine ; but 
 if we unite all the evil consequences, it will be found that not 
 less inconvenience follows from ranking under this head, as is 
 daily done, thousands of cases of remittent. 
 
 In truth, it seems to me that the evils are greater ; for it is 
 thus, among other things, that the means of prevention are over- 
 looked ; while, if those who thus argue against the non-contagious 
 nature of fevers, have unintentionally confirmed the opinion which 
 pervades this work, they have not seen the whole truth, nor seen 
 it in that manner which would alone render their opinions useful ; 
 not inquiring into the real cause and nature of such fevers, but 
 most generally attributing them to fanciful ones, and acting ra- 
 ther under the spirit of opposition than in that of philosophy. 
 
 If, however, I cannot exactly prove that bilge water is capable 
 of generating Malaria and fever, I am not at least very far from 
 that proof, since the mortality in sugar ships is always notedly 
 greater than with any other cargo, and has often been most de- 
 structive ; while I need scarcely repeat that it is notoriously the 
 very worst of cargoes in this respect. And the opinion is further 
 supported by a great mass of facts occurring in merchant ships 
 and in the navy ; while their numbers may perhaps compensate 
 for their want of speciality. The general experience is, that a 
 foul ship, and foul, as ships are, from bilge water chiefly, is in- 
 variably a sickly ship, and that vessels of this character, fall- 
 ing under the command of an attentive captain whose rule it 
 
CASES OF MALARIA. 71 
 
 has been to wash the hold by means of a plug, daily, till the 
 water came up as transparent as the sea outside, have recovered 
 their health, as they have also remained free from disease. Such 
 was the rule, for example, of Sir Henry Baynton, who cannot 
 object to see his name thus quoted for good; and such was the 
 rule of Captain Smyth, who during his long and well known 
 services in the Mediterranean survey, never experienced fever, 
 on any occasion, on board of any one of the various ships which 
 he commanded. 1 may bestow the same praise on Parry, as also 
 on his great predecessor, Cook ; while among hundreds of exam- 
 ples of the reverse, far too easy to find, I shall notice but one, 
 since they are not so agreeable to point out This occurred on 
 board of the Powerful, a seventy-four ; which was entirely dis- 
 abled by sickness, by fevers, during her passage from the East 
 jlndies, while, when examined, her ballast was found to be, from 
 ;neglect, a mass of putrid mud, the unquestionable cause of all this 
 evil. 
 
 In reality, I entertain no doubt, that while we must suppose 
 contagious fever to occur occasionally in ships, from various ob- 
 vious causes, the great and frequent mortality in them has ever 
 (proceeded from this very cause, Malaria, the Malaria produced 
 ;by the neglect of cleanliness; and that the fevers so generally 
 Reputed typhus, have been the remittent thus generated. Hence 
 also the frequent failure of fumigation ; as this can possess no 
 power against a daily productive and ever renewed source of 
 disease : though it might produce the expected effect for a day or 
 more. Against that there can be no remedy but to extirpate the 
 cause by absolute cleanliness in the hold, or by the constant use 
 of the plug : while 1 entertain no doubt, that if this rule were 
 made imperative on all commanders of vessels, not only in the 
 Navy, and under a fixed regulation of the admiralty, but in the 
 merchant service, by ship owners, and very especially by the 
 West India trade, the fevers which are now so frequent would 
 disappear. 
 
 There can be no other causes of remittent fevers at sea ; the 
 case of tropical harbours being of course excluded: and if, in 
 addition to this care, it were also a rule to fumigate every vessel 
 with sulphureous acid before leaving port, for the purpose of de- 
 stroying any casual contagion which might have found its way on 
 board, taking also such obvious precautions with respect to the 
 crew as do not require to be described, it is almost impossible 
 'that what, almost alone, deserves, as it receives, the name of 
 sickness, at sea, should exist ; while an immense mortality, inju- 
 I rious, and deeply inconvenient, in far more modes than the mere 
 waste of life, would be prevented, hereafter, and for ever. They 
 who know the history of commerce, or of navigation under what- 
 
72 OBSCURE AND DISPUTED 
 
 \ 
 over forms, know well what has been thus suffered, and is, daily, 
 suffered ; and they know too, that if fevers are but excluded, the 
 diseases of the sea are, in the present day, nothing. 
 
 I cannot cease to wish that these opinions were more widely 
 promulgated ; convinced that in stating them, I am offering the 
 means of widely saving human life ; and not only so, but of pre- 
 venting those losses of property, of commercial wealth in various 
 modes, and those disappointments, not merely in trade, but in 
 naval warfare, which are but too well known to those who know 
 what has been the history of our naval wars. The spirits of tens 
 of thousands might join with " Hosier's Ghost," in remonstrance 
 to those from whose neglect or ignorance it has arisen, that their 
 bodies were committed to the deep, the unhonoured victims of 
 pestilence, not the bold defenders of their country's glory. 
 
 I know not where, better than here, I can also introduce 
 another cause of Malaria little noticed ; one at least which is 
 universally believed and asserted to be a cause, by the French 
 physicians who have bestowed most attention on this subject. 
 This source of fevers is found in the dunghills and pools so com- 
 mon at the doors of farm-houses, and more especially of cottages 
 and petty establishments, in almost every country. That, in 
 common with sewers, ditches, and other similar repositories of 
 putrefying vegetable matters, they do produce autumnal fevers in 
 France, is not only believed, but, as far as we can trust those 
 reporters, fully proved ; nor after all that has here been said on 
 this subject, is there any reason for doubting the fact. If it be \ 
 equally true in our own country, as may equally be suspected, i 
 especially in hot and peculiar seasons, it offers a new argument' 
 against this discreditable fashion; while it may also explain many 
 of the fevers occurring in the country every year, where no ob- 
 vious source of Malaria exists, and which, as usual, are reputed; 
 as typhus. 
 
 In how far mere mud, the apparent produce of the sea, or left 
 by the recess of the tide, in ports and estuaries, and at the mouths 
 or on the banks of tide rivers, can or does produce Malaria, is one 
 of the questions on this subject which has been argued on differ- 
 ent sides. That such mud, appertaining to fresh waters, and laid 
 bare by the summer heats, in lakes, pools, and canals, does pro- 
 duce fevers, and of a very serious character, has been formerly 
 shown. In such cases, it might be easily conjectured, and is in 
 fact known, that the mud contains, not merely vegetable matters 
 in a state of decomposition, but animal matter also ; though in 
 how far animal matter can produce or aid in the production of 
 Malaria, is a point which has never been decided, however often 
 it has been suspected, and even asserted. Now with respect to 
 marine mud, it cannot be supposed that clay and water alone 
 
CASES OF MALARIA. 7A 
 
 could give rise to this poison, so that it is easy to understand 
 where the exceptions would be found ; while if it contains putre- 
 fying sea plants, there is no reason why it should not be as perni- 
 cious as the mud of lakes, inasmuch as the presence of salt is no 
 remedy, here, more than in the case of salt marshes. Or, as it is 
 the effect of tides, in estuaries and similar circumstances, to reject, 
 and often therefore to expose the mud brought down by rivers, it 
 is plain that, even without the presence of marine plants or their 
 remains, such mud must often be in the same circumstances as 
 that of lakes in summer. In our own climate indeed, where the 
 heat of the sun is less likely to operate an injurious effect of this 
 nature within the few hours of low water, such a result is less 
 likely ; while deceptions may easily arise in this case, from the 
 fact that, in those situations, there must often be marshy land in 
 the neighbourhood, or, as in Southampton river, exposed banks 
 of living Zostera, acting probably the part of a marsh. 
 
 But though 1 have formerly remarked, that odour, or the smell 
 of putrefying vegetables, is not an exclusive test of the presence 
 of Malaria, and is assuredly not necessary to its existence, any 
 more than that the fetid gas is itself the poison in question, a re- 
 mark which is further completely proved by the fact that marsh 
 lands emit as bad an odour in winter as in summer, and yet with- 
 out producing disease, we can never consider as safe, those sea 
 ports, generally dry harbours, which emit the smell of putrid sea 
 weed at low water ; while, most of all, are those suspicious which 
 receive the sewers of the towns themselves. It may even be sus- 
 pected that to manure land with that substance is not a safe ope- 
 ration ; while as to the former case, there is evidence in abun- 
 dance, even from Europe, even indeed from England, to prove 
 that fevers, and in summer as usual, are the actual produce of sea 
 ports or harbours under these circumstances. 
 
 In France, and in Holland very especially, this has been proved 
 in innumerable instances ; and, in fact, many of the most severe 
 epidemics of this latter country have been traced* to this very 
 cause, the, exposure of sea weed, whether on the shores or in the 
 interior lands. In the Mediterranean, the nature of the tides is 
 less likely to produce any very conspicuous effects of this nature, 
 yet they are far from being unknown ; and as to our own coun- 
 try, though they may be less common or marked than in France, 
 I have no doubt that the fevers so common in sea ports are in re- 
 ality owing to this very cause ; while, by the usual error, they 
 are always reputed as typhus, or as contagious disorders produc- 
 ed by poverty, want of ventilation, and the other circumstances 
 attached to such places, and so often unjustly accused of what is 
 not their consequence. In how far any modes of prevention 
 might any where be derived from this view, it would be impossi- 
 
7 1 ■ OBSCURE AND DISPUTED 
 
 ble to inquire, except for each particular case ; but it is the fun- 
 damental step of greatest importance to assign the real cause, and 
 the real nature of the fevers so universally mistaken. 
 
 I know that the case of Venice has been adduced against this 
 opinion ; but whatever was its freedom from disease in the clas- 
 sical times, as, in consequence of a different state of things often 
 here noticed, was then true of many other parts of Italy, it is not true 
 that Venice is now free from summer fevers, while it is a fact 
 that its unhealthiness has been gradually increasing for a long 
 time past. Even were it not so, the slender vacillations of the 
 Adriatic tides would prevent any great exposure of mud in this 
 case ; and thus explain the exemption : while it is not less notori- 
 ous, that from a peculiarity in the currents in this singular place, 
 the lagunes are freed from that mud which would otherwise ac- 
 cumulate, and produce what has happened in so many other pla- 
 ces, even on this shore. 
 
 That mere mud, maritime as well as terrestrial, containing ve- 
 getable matter, yet free from any herbaceous or closely investing 
 vegetation, does produce Malaria of the most destructive nature, 
 in the tropical regions, or under appropriate circumstances of cli- 
 mate or heat, is amply proved, if further proof were necessary, 
 by what occurs in the Mangrove rivers, whether of Africa or else- 
 where. In such situations, it is well known, this tree forms 
 dense and extensive thickets or forests, if forests they can be call- 
 ed, through which, at high tides, the trunks, such as they are, 
 are found rising out of the water, producing such an effect to the 
 eye, as might happen with us from the inundation of a wood ; 
 while, on the recess of the tide, it is seen that they are rooted in 
 this bare mud, which they serve to retain and consolidate ; thus 
 becoming important geological agents in the extension of the allu- 
 vial lands of the rivers. 
 
 Now, on this subject, I have carefully cross-examined intelli- 
 gent naval officers, and it has been their decided opinion that the 
 cause of the fever, or the Malaria, so frequently and extensively 
 fatal to the crews of boats when sent up these rivers, was extri- 
 cated during low waters, and from the mud, while it was attend- 
 ed by a peculiar smell, described rather as an earthy than a putrid 
 one. And that opinion is confi-med by the fact, that in cases 
 where such a river-course extended for miles, no other source of 
 Malaria could be present ; while mere approximation to the thick- 
 ets, from the sea, was sufficient to produce the fever, and almost 
 instantaneously, provided the mud was bare: the navigation of 
 such a stream being safe at high water. 
 
 In such cases, unquestionably, the cause must be sought in the 
 decomposition of the vegetable matters which are mixed with the 
 mud: fragments and leaves from the trees themselves, together 
 
CASES OF MALARIA. 75 
 
 probably with anologous matter brought down by the stream. 
 Yet, that in such extreme cases as this, the smell of vegetable pu- 
 trefaction is not present, serves to prove also, that putrefaction, in 
 the proper sense of the term, is not necessary to the production 
 of Malaria, but that the stage, or mode, of vegetable decomposi- 
 tion required for the production of that poison, is different from 
 that which generates a fetid gas. As I remarked before, the two 
 may co-exist, possibly in different places or parts, at one time, 
 possibly even in the very same place or substances ; but we must 
 not consider the smell of putrefaction as necessary, or imagine 
 ourselves secure because it is not present. Or, the gas which is 
 Malaria may be mixed with the fetid gas, or else either may exist 
 without the other : while the process of decomposition may, and 
 even at the same period, or stage, for aught that we know to the 
 contrary, produce either the one or the other, or both united. 
 Here also there is an analogy to the matters of contagion. These, 
 all of them, it is well known, can be present without being sensi- 
 ble to the smell : but they are often also united with some matter 
 producing fostor, as such smells may exist, even in great intensity, 
 without including the matters of contagion. 
 
 Though, in a former place, I was compelled to notice this ques- 
 tion as it relates to sewers and drains, from their connection with 
 the ordinary agricultural works of a similar nature, it is one which 
 might equally have found its place here, thus intricately are all 
 those subjects connected. These are cases, properly, of mud 
 without actual vegetation, or of the decomposition of dead, and 
 very frequently of disorganized vegetable matter ; and the whole 
 serves to prove that a living vegetation is not necessary to the 
 production of this poison. If Fleet ditch was ever the source of 
 disease that it was supposed, it is one out of numerous proofs on 
 this subject ; while I need scarcely repeat here, that the perni- 
 cious character of such receptacles, both close and open, has been 
 a prevailing opinion among physicians at all times and places, 
 however often the nature of the fevers produced by them may 
 have been mistaken : while a variety of facts connected with the 
 police reforms and previously neglected condition of towns, if far 
 too numerous and often too loose to be quoted as proofs, seem 
 amply to justify, from experience, that the air extricated in such 
 circumstances, if it be not all Malaria, or always containing that 
 substance, is frequently a real cause of the fevers of this character 
 which have so notoriously prevailed in ill-regulated towns. 
 
 To pass now from the question of mere vegetable putrefaction, 
 there is an assertion respecting the production of remittent, of a 
 very different nature, in which there may, or rather must be, a 
 fallacy involved. According to the testimony of African travel- 
 lers, and of Park in particular, it is produced immediately on the 
 
*C> OBSCURE AND DISPUTED 
 
 fall o( the rains, as if the mere contact of the rain itself was the 
 cause. Such indeed appears to be his opinion. I cannot deny 
 here what I have not seen ; but it must be recollected that this 
 rain falls in a climate and at a moment when the whole atmos- 
 phere is, or has just commenced to be, one mass of Malaria, and 
 that in the circumstances noticed, it would always be at least an 
 accessary or predisposing cause. In this case it may be no more, 
 if it be even that. 
 
 The facts, as more accurately stated by other travellers, and 
 also in some measure by himself in other places, seem to be, that 
 as the vegetable decomposition necessarily active in so hot a cli- 
 mate, commences as soon as the ground becomes wetted, the ge- 
 neration of Malaria begins, perhaps even on the first day or hour ; 
 and that, in this as in every other case, it is but the produce of a 
 vegetating soil, rendered suddenly marshy or wet under a high 
 temperature. That this is the view entertained by the natives 
 themselves, is plain, from the care with which they retire to their 
 houses and endeavour to exclude even the least access of the ex- 
 ternal air : judging, what is probably true, that the whole atmos- 
 phere is one wide body of Malaria. As the rain increases, how- 
 ever, and the ground becomes thoroughly wetted, the diseases 
 diminish, returning again as the retiring of the rains allows it to 
 dry. Hence it is, that in Africa and elsewhere, the greatest in- 
 fluence of the Malaria takes place at the end of the rainy season ; 
 and thus also it was on the retiring of the waters after the rains 
 and the inundation, that the great mortality commenced among 
 our troops at Rangoon in October. 
 
 This fact is, in another sense, of some value, as tending to ex- 
 plain what I formerly remarked respecting the occasional increase 
 of Malaria in certain parts of Europe from attempts at drainage. 
 It serves to show what was then suggested, that a very wet stale 
 of the soil was not so injurious as some one intermediate between 
 complete inundation, or sw r ampiness, and absolute dryness. 
 
 And if it is easy to see, without a more minute explanation, how 
 it bears on this, and on many collateral or similar cases readily 
 affiliated to it with a little reflection, it is a fact also which illus- 
 trates in that satisfactory manner which is always the result, as 
 it is the proof, of a philosophic \1 principle truly assumed in sci- 
 ence, all these facts of an analogous nature which occur in our 
 own country. In Africa, as in other tropical climates, if there is 
 neither spring nor autumn, these two periods, as far as they re- 
 late to the production of Malaria, are represented by the falling of 
 the rains and by the retirement of the waters; while they may 
 be separated but by a few weeks, instead of being placed, as with 
 us, at an interval of half the year. The analogy is maintained 
 throughout; and the consequences are the same, varying chiefly 
 
CASES OP MALARIA. 77 
 
 in intensity or degree. I need not detail the points of resem- 
 blance more minutely ; while the differences, and their causes 
 also, are obvious. 
 
 There is yet another common opinion on this subject, which 
 seems to imply a decided fallacy of observation united to a pre- 
 judice, and to which I alluded not long ago. To drink bad wa- 
 ter in hot climates, as is a necessarily frequent occurrence, is so 
 commonly reputed a cause of fevers, that it may seem hazardous 
 [to question its truth. But whatever accessary ill effects this may 
 produce, it is always forgotten that this bad water occurs, only, 
 or chiefly, when the land is of such a nature as to be in itself a 
 source of Malaria; as the cases recorded are never those of the 
 brackish or half putrid waters of the sandy deserts, but of those of 
 low and marshy lands, or of situations where, with any water, fe- 
 vers would be produced. Were the water alone, as drink, the 
 cause of fever, it should occur equally in all places, not only in 
 the deserts of Africa, but in numerous cases, in towns, where, ne- 
 vertheless, this consequence has not been observed. That such 
 waters may produce diarrhsea, is not denied ; but even here, 
 there is a wide difference between such a disease and the dysen- 
 tery of Malaria. On this illustration however I must not lay any 
 'stress ; having already placed it among the facts demanding fur- 
 ther investigation. 
 
 I am not aware that among what else I might have recorded 
 on this subject of obscurities, there is any thing more so very far 
 differing in principle from what has now been stated, or so very 
 material, as to justify me in prolonging this part of the present 
 chapter. If I have omitted any thing on which I might have ex- 
 plained myself further, I do not imagine there can be aught which 
 will not be easily understood now, from a due application of the 
 leading facts which have been discussed. Yet I will not conclude 
 without one further note. 
 
 It is a popular prejudice in Italy, that volcanic soils are espe- 
 cially productive of Malaria, or rather, that they are intrinsically 
 capable of producing it. On what principles, it may be asked? 
 If this be mere assertion, a counter assertion is not more worth- 
 less ; and neither deserves attention. If it is matter of evidence, 
 it must either be admitted, or met by counter proofs. I possess 
 no knowledge either way ; but it is the duty of the Italian theo- 
 rist to see that he has not overlooked essential circumstances, 
 and, here also, given us a causa pro non causa. When another 
 philosopher of the same stamp asserts that the production of Ma- 
 laria is here regulated by a mine of pyrites, and so forth, extend- 
 ing from some place to some other place, it is not difficult to 
 know what to believe. The truth, as to the former fancy, may 
 probably be, that the soils of this class are the most fertile ; but as 
 
 L 
 
7o OBSCURE AND DISPUTED 
 
 it is a subject not worth inquiring of further, I shall terminate this 
 chapter with the examination of a somewhat intricate question 
 relating to Rome, as it relates to the production and effects of 
 Malaria. 
 
 The relative states of ancient and modern Rome, and of the 
 neighbouring country, with respect to the production of Malaria, 
 as indicated by a difference, real or imaginary, in their salubrities, 
 would, if the superiority of former times in this respect were re- 
 ally proved, offer a difficult problem on this subject. That such 
 an opinion has been entertained by some writers on this question, 
 will not however prove that the fact was so ; but as it is a very 
 entangled inquiry, and as I do not conceive that we have yet at- 
 tained that degree of knowledge as to the causes of Malaria 
 which will enable us to pronounce decisively on either side, I 
 shall detail the necessary facts as briefly as possible, as they can 
 be collected from the classical writers. That Brocchi has sup- 
 posed ancient Rome to have been more healthy, yet not less sub- 
 ject to Malaria than the present city, explaining the supposed fact 
 by a difference in the mode of clothing, is a solution which I must 
 examine in another place. 
 
 The ordinary conclusions of natural history will determine, in 
 the first place, that the site of Rome, as well as the surrounding 
 country, must, at its foundation, have been a tract of woods, 
 lakes, and marshes ; and, that such a territory must have been 
 productive of fevers, appears an inevitable consequence. In spite 
 of this, the city flourished and increased, while the surrounding 
 country was also filled with a population distributed in hamlets 
 and villages. The plain of Latium for example, which is now a 
 desert, was, at that time and long after, rich and populous : and 
 thus also the lake of Castiglione, now infamous for its pestilential 
 air, was the seat of a powerful city which long resisted the arms 
 of Tarquinius Superbus. The ancient Laticum was situated near 
 a marsh which is now one of the most destructive spots in this 
 district ; and the Romans erected baths beyond the Anio, in a 
 place which is, at present, too hazardous even to be visited. The 
 Lago di Giuturna was a favouriu rtfa the ancient Romans ; 
 
 yet in later times it rendered Casirl Candolfo uninhabitable, and 
 was therefore drained in 1611, by Paul V. In the time of the 
 \olsci there were twenty-three luvvns and villages in the Pontine 
 marches, of which Ardea and Lavinium were two. Bui as it is 
 unnecessary to accumulate more of iheso specific iacts, I shall 
 only further remark, that history confirms what might have been 
 inferred from general considerations, namely, that the country 
 round Rome was in ancient times interspersed with what were 
 called lakes, and which were, in fact, chiefly marshy pools ; as 
 must necessarily be the character of accumulated water in a 
 
CASES OF MALARIA, 79 
 
 | country of such a form and distribution. And these tract?, which 
 jj were then populous and flourishing, are now uninhabited deserts ; 
 is although the lakes and marshes have comparatively disappeared, 
 | under different attempts at drainage, attended by various success. 
 
 With respect to the city itself at that early date, the facts are 
 | similar and the conclusions not less puzzling. About the earliest 
 period of which we have any distinct knowledge, the town was 
 j limited to the Quirinal, the Palatine, and the Capitol, and at the 
 livery foot of these, lay the great and the little Velabrum; besides 
 i which, we must recollect the Caprean marsh and that of Teren- 
 tum, the whole forming, as can scarcely at least be doubted, a 
 j focus of Malaria and fevers. Yet, that while the surrounding 
 | country was populous, the city also increased rapidly in popula- 
 tion, even at the earliest period, is evinced by various facts which 
 I history furnishes ; of which I need only notice, that the first cen- 
 sus by Servius Tullns, produced 80,000 citizens, capable, as is 
 supposed, of bearing arms ; whence the general population can 
 be conjectured. And if we examine how the fact stood as to the 
 neighbouring towns, we shall find that Ardea, which now reckons 
 six hundred inhabitants, was then able to raise an army sufficient 
 to resist Rome and also to send a colony to Saguntum : and that 
 Ostia, now I believe inhabited by a single innkeeper, became a 
 flourishing city soon after its foundation by Ancus Martins. 
 
 Such is a sufficient statement of this class of facts. Whether 
 the production or the virulence of the Malaria has increased in 
 modern times, or whether the ancient inhabitants had means of 
 resisting its influence which the moderns have not, are the ques- 
 tions that remain to be solved, unless some other collateral cause 
 of this extraordinary difference can be assigned. It cannot be 
 safely asserted that at any period of the history of Rome, the city 
 and the neighbourhood were free from this plague and its conse- 
 quences ; while there is indeed much reason to infer that it was 
 as poisonous, essentially, then, as it is now, though the apparent 
 effects or the political consequences were less severe. This seems 
 easily proved from history ; and still we continue harassed with 
 difficulties as to the solution of what has, to some writers, seemed 
 almost an enigma. 
 
 It may be thought indeed, that as to some parts of this district, 
 
 if not to all, the evil has really increased in modern times, not 
 
 | solely from the decay of agriculture arising from that injudicious 
 
 j political management as to corn laws, so often blamed, and from 
 
 | other analogous causes as often discussed, but from geological 
 
 changes as to the form of the land itself; and of such facts and 
 
 their consequences, to a certain extent, there seems ample proof. 
 
 The joint action of the sea and the rivers will, in the case of the 
 
 Pontine marshes, easily explain a change on this important point, 
 
80 OBSCURE AND DISPUTED 
 
 fully adequate to an increase of the evil : and reasoning of an ai 
 alogous nature may be applied, under modifications, to more in- 'X 
 land districts. 
 
 It is also not an unimportant remark in this case which we de- I 
 rive from Theophrastus ; namely, that the plain of Latin'jm was 
 covered, and especially towards the sea, by forests of laurel (bay) 1 
 and myrtle, of such size as to be used in ship building; constitu- 
 ting, doubtless, screens to protect the country from the pernicious 
 southern winds, and to check the propagation, if not the produc- p 
 tion, of Malaria. And while this was the fact, it is not less plain 
 that the ancient Romans knew the value of this expedient ; and ' j 
 thus, it is probable, was averted much of the evil which modern 
 changes as to this point have introduced. The Law of the Twelve 
 Tables " Lucos in agris habinto," seems to have been directed to 
 this end ; and hence also the sacred character of groves, and the 
 heavy penalties denounced against those who destroyed or injured 
 them. How truly this was the chief, and perhaps the only rea- 
 son, is proved by what Pliny says of their property to absorb and 
 destroy the mephitic vapours, unfounded as his theory may be. 
 If, further, we consider the great changes which are produced in 
 the salubrity of a country by changes in the modes of cultivation, 
 as well as by planting, or even by the reverse, changes which 
 even affect the general climate independantly of their local effects, 
 it would not be very difficult to comprehend how the ancient and 
 modern conditions of the Roman territory may have been really 
 different, while where difficulties arise on the examination of 
 particular facts, it must be recollected that none of these can be 
 judged of on general grounds, nor without an ample knowledge 
 of every circumstance ; as the very same treatment or change 
 which may be salutary in one country or tract, may be pernicious 
 in another. As to the changes of climate to which I have just al- 
 luded, the produce of various concurring causes, it will be another 
 question how far that change in the temperature of Rome and its 
 neighbourhood which is proved by the accounts of the classical 
 writers, may have lent its 'aid towards increasing the produce and 
 severity of the Malaria. 
 
 But it would far exceed my necessary bounds to enter further 
 on these details ; and I may merely remark that the first great 
 territorial change appears from history to have occurred after the 
 invasion of Attila, when the Tiber broke loose, and, from want 
 of care, the Campagna became a marsh. The drainage was how- 
 ever renewed under Theodoric, by Cascilius Decius ; but on the 
 expulsion of the Goths, this tract was again neglected, and fell 
 back into the same state. If under a succession of Popes, com- 
 mencing with Boniface VIII., and followed by Martin V., Cle- 
 ment VII., Pius V., Clement XL, and afterwards by Sixtus V. 
 
CASES OF MALARIA. Gl 
 
 and Leo X., various attempts were made on the Pontine marshes, 
 little success was the consequence; while, according to Prony's 
 report, the efforts of Pius VI. terminated no less in a waste of 
 money. But as I dare not pursue this local subject, nor attempt 
 to strike the balance as to the territorial conditions of ancient and 
 modern Rome, I may proceed, confining myself as strictly as 
 possible to the question which Brocchi has started ; the first object 
 being to show that Malaria and its consequences were the scourge 
 of ancient as well as of modern Rome. 
 
 By the testimonies of Solinus and Dionysius of Halicarnassus, 
 it is proved that the first settlers were obliged to abandon the 
 Palatine mount, in consequence of the pernicious exhalations of 
 the Velabrum ; and we are also informed by Columella, that the 
 land near Tusculum, cultivated by Attilius Regulus in the first 
 Punic war, was pestilential : the Malaria of that tract being pro- 
 bably produced by the present Lago di Castiglione. It is further 
 probable that the larger proportion of pestilences described by 
 the Roman writers, were unusually severe visitations of the marsh 
 fever ; though at this distance of time, and under information 
 which is not medical, we must not absolutely decide that some 
 of these may not have been instances of contagious fever, perhaps 
 even of plague. Such may probably have been the pestilences of 
 355 and 573, since there are facts in Livy's narrative which rather 
 seem to justify this conclusion ; and such possibly were the cases 
 in which the city alone suffered, while the surrounding country 
 was exempt. But allowing even much for this, we find from 
 Plutarch, that noted periods of sickness occurred in the time of 
 Romulus and in that of Numa, while similar ones are recorded 
 of the reigns of Servius Tullus and Tarquinius Superbus : and 
 when Livy says that in the short period of 173 years, or, from 
 287 U. C. to 460, there occurred at Rome or in the surrounding 
 country, no less than nineteen distinct plagues, none of them at 
 longer intervals than seventeen years, and some lasting two or 
 three years together, it is not possible to avoid concluding that 
 the fever of Malaria must have prevailed then in as great severity 
 as it does at present. 
 
 But even putting aside mere inferences of this nature, we have 
 the direct testimony of many writers of the time of the Republic, 
 as to the insalubrity of the climate and the occurrence of au- 
 tumnal fevers. Cato mentions places where it was impossible to 
 live on account of the badness of the air; Livy speaks of tertians 
 and quartans ; and Varro advises the proprietor of an unhealthy 
 farm to sell it at any price, and in case that was impracticable, 
 to abandon it, unless he was desirous of being confined as a mad- 
 man. 
 
 And that the country in question was unhealthy, and known to 
 
OBSCURE AND DISPUTED 
 
 be so, from Malaria and from marshes, is further proved by the 
 repeated attempts at drainage, even in very early days. The 
 Consul Scaurus drained a tract of marshes on the Po, and Marcus 
 Curius Dentatus executed a similar operation on the lake near 
 Rieti. When it is related by historians that the armies were of- 
 ten obliged to quit their encampments near marshes, on account 
 of diseases, it is evident that the fact was as well understood as it 
 was common. That the necessity continued, and was never for- 
 gotten, is further apparent from a drainage executed by Cornelius 
 Cethegus near Rome, and from the intentions of Julius Caesar, 
 frustrated only by his death. In Egypt, still later, Augustus (then 
 Octavius,) cleansed the canals of the Nile for similar reasons, and 
 afterwards carried on some operations towards the same end, at 
 home. Between the periods of this Emperor and Gratian, the 
 Pontine marshes were maintained in a dry state for 300 years ; 
 and we trace every where a great anxiety in keeping canals clean, 
 while there is little doubt that analogous considerations entered 
 into the reasons for constructing the celebrated but disputed 
 Cloacae. To put this matter indeed out of doubt, Strabo says 
 very positively, that this healthiness was owing to the attention 
 bestowed on drains, forests, roads, and so forth ; nor need we 
 doubt the existence of this knowledge even in times much more 
 ancient, when we find it recorded of Empedocles, that he reform- 
 ed an unhealthy district by turning the courses of two rivers, when 
 those who, in Greece, rescued marsh lands to cultivation were 
 exempted from all taxes and public services, and when the very 
 fable of the Lernoean hydra and the deeds of Iiercules, is but the 
 poetical record of a successful operation of this nature. 
 
 It is true, undoubtedly, that even in the times of the Empire, 
 the Campagna continued to be inhabited ; since, during the reigns 
 of the Caesars, the thirty-one country tribes were dispersed in this 
 district. Yet that the city, and the country also were unhealthy, 
 and subject to annual fevers, is a fact so very familiar, in conse- 
 quence of the numerous and well-known writers of that period, 
 that it is superfluous to do more than remind the reader of the 
 names of Columella, Varro, Strabo, Martial, Horace, Seneca, 
 Galen, and of the regular migrations which all who could contrive 
 to leave the city made to their country seats ; to Baia3, Benacus, 
 Tusculum, Tiber, and so forth, as much for the purpose of avoid- 
 ing the fevers, as from that love of the country for which the Ro- 
 mans had been distinguished from the earliest periods of their 
 history. 
 
 But to end. If any thing should be urged in favour of the su- 
 perior salubrity of former or early Rome, from the comparative 
 want of records of disease, it must be remembered that there 
 were, for a long time, no writers, and for a further long period, 
 that they were rare ; and, moreover, that professors of physic 
 
 
CASES OF MALARIA. 83 
 
 j were long unknown to this rude people, since, according to Pliny, 
 | the first of these appeared from Greece in 535. Nor, from what 
 ' we know of the political situation of the inferior classes, was it 
 I probably considered a matter worthy of much notice, should a 
 ! few thousands, whether citizens or slaves, die in every autumn : 
 ! while the blank also was rendered speedily insensible in a popu- 
 1 lation almost hourly recruited from every quarter of the known 
 I world. To which I may further add, that from the crowded state 
 ! of the people, in houses and streets, (a circumstance well illus- 
 j trated by Gibbon,) it is probable that the ravages of the Malaria 
 I within the walls was materially checked, on the principles which 
 ! I have elsewhere explained in speaking of the propagation of this 
 poison. 
 
 With respect to the country without the walls, or the rural po- 
 pulation generally, 1 have but one supposition more to offer; and 
 i if it is not capable of explaining the difference of the population 
 in ancient and present times, as far as that depends on the cli- 
 | mate, I must leave the solution to more ingenious persons. I 
 have elsewhere shown, that in the same soil and under the same 
 general state of drainage, a tract of land under the plough is less 
 ! injurious than in pasture or meadow, whence it is possible that 
 I the greater salubrity of ancient times was an effect of a cultiva- 
 tion, forced, or demanded, to a greater extent, by the superior 
 political condition of Rome at that time. It is also easy to ima- 
 gine, that under such a state of things, many partial systems of 
 drainage and care, added to those under the direction of the state, 
 existed ; maintained by that population which, forced by circum- 
 stances, was also preserved and renewed by that demand for in- 
 dustry, the elasticity of which would fill such blanks as were an- 
 nually produced by disease. And if there is any truth in this 
 latter view, one of the greatest differences between ancient and 
 modern Rome on this point, may be rather a political than a phy- 
 sical question ; the difference between a state of activity and 
 wealth despising disease, and one of sloth and poverty retiring 
 before it, and in retiring, giving it also the means of acting with an 
 accelerating effect. Assuredly Egypt has never been without its 
 plagues and fevers ; yet a vigorous government and an industrious 
 people contrived to maintain, in spite of them, a condition of po- 
 pulation and wealth which has failed only under the more exter- 
 minating Malaria of Turkish ignorance and despotism. Such also 
 is fast becoming the fate of Venice ; long noted, and even in mo- 
 dern times, for its pecuilar salubrity, but now rapidly undergoing 
 a depopulation, in which disease, formerly unknown or unnoticed, 
 is taking its share ; and probably destined in no long time, under 
 Austrian love and wisdom, to become what even Rome threatens 
 to be, or to suffer that fate under which Alexandria, once more 
 wealthy and not less proud, has long since fallen. 
 
( 84) 
 
 CHAPTER VI. 
 
 0?i revolutions and changes which take place with regard to the 
 production of Malaria, whether from natural causes or from ar- 
 tificial sanitary measures. 
 
 i 
 
 Independently of the revolutions or irregularities in the produc- '. 
 tion of Malaria which depend upon season, and of which I shall " 
 treat hereafter, there are others which arise from changes in the 
 condition of the generating soils ; and as these questions are of 
 considerable importance in a statistical view, it will be necessary ' 
 to examine them as far as the present state of information admits. ] 
 And as the latter cause implies the remedies applicable to the 
 diminution or extermination of this pernicious property in a soil, , 
 this branch of the subject will also find its place here, as far as it 
 was not already noticed, and as is admissible in a work which 
 does not profess to examine that department of general eco- E 
 nomy. 
 
 As the revolutions in the generation of Malaria can be judged 
 of, like its existence, only by the diseases which it produces, and : , 
 by changes as to their prevalence or severity, I must commence 
 by remarking, that alterations as to the facility of its propagation 
 or as to the direction in which it is propagated, may deceive us 
 in attempting to decide on the absolute increase or diminution of 
 this poison from the action of the soil itself. The cases of this 
 nature will be deduced from the following chapter, where the 
 propagation of Malaria is examined. It follows from all that has 
 been said in the preceding chapters, that whenever a soil former- 
 ly dry becomes marshy or wet, from any of those changes to 
 which the surface is exposed, we may expect an increase or a y 
 new production of this substance, while it should, on the contrary, 
 diminish or disappear in the reverse circumstances. Practically, 
 this proves to be true ; while the latter change, following the 
 drainage and improvement of lands, points out that process as the 
 remedy. But the modifications of change in both these instances* 
 being various, it is necessary to specify a few of the most essen-,- 
 tial. 
 
 The simplest and the best known case of the diminution of 
 Malaria, is that which arises from the drainage of, marshes, 
 swamps, or fens ; and, to that forinage, governments and the peo- 
 ple both, have often had recourse with this very view, since this 
 
REVOLUTIONS, &C. 85 
 
 is a part of the subject on which there are no differences of opin- 
 ion. This is the great change to which we must attribute the 
 improvement of our own island in this respect ; and it is one also 
 of which the effects are extensive throughout Europe in general ; 
 while, in the tropical climates, as well from the inherent difficul- 
 ties of the subject itself, as from the wretched condition of most 
 of the governments in these countries, little improvement of this 
 nature can be quoted. It is probable that examples might be ad- 
 duced from China ; but we are as yet almost unacquainted with 
 the geography, statistics, or history of that country, though the 
 former at least promises now, in the hands of Klaproth, to be no 
 longer the disgrace of our maps. 
 
 It is very well known that, in England, before the great increase 
 of industry and knowledge, there were numerous and extensive 
 tracts of marshy land ; while if we recede to a much more dis- 
 tant period, the early history of Britain will inform us that this 
 was almost the general character of the inhabited parts of the 
 country, since it was in such spots that our savage ancestors for- 
 tified themselves from foreign as well as domestic enemies. It is 
 to the Romans that we are indebted for the great and early re- 
 forms of this nature, and very probably for the first ones ; since, 
 they were well acquainted with the injurious qualities of such 
 land, and the method of remedying its evils while they also ren- 
 dered it productive. That the wet tracts or marshes of Somer- 
 setshire were rescued by them, is almost matter of demonstration ; 
 and it is equally probable that to them also we are indebted for 
 the original embankments of the Thames. 
 
 If a long blank of barbarism as to the inhabitants, and of igno- 
 rance as to ourselves, respecting the statistical condition of Eng- 
 land, succeeds this period, neither have we any medical records 
 by which we can prove, what nevertheless we may safely con- 
 clude, that fevers, of each nature, prevailed throughout those days 
 of neglected improvement and agriculture, to a degree infinitely 
 greater than they do at present. This is what we might fairly de- 
 cide on, without absolute evidence ; but as we descend in his- 
 tory, and as we trace the progress of agricultural improvement 
 nearer to our own days, we discover, as I have formerly shown, 
 facts enough to justify this conjecture. It is from casual reading 
 of various kinds indeed, that we must ascertain the prevalence of 
 fevers and intermittents during the ruder periods of our history ; 
 but when we can, by receding upwards from our own time, dis- 
 cover a gradually greater prevalence of such diseases, and when 
 we find the melioration, reversely, following very accurately the 
 progress of agricultural improvement, the whole conclusion ap- 
 pears to be amply justified. 
 
 To examine local details with this view in our own immediate 
 
 M 
 
8G REVOLUTIONS AND CHANGES 
 
 would be as easy as it might be rendered long, and as it 
 would be superfluous. The progress of Lincolnshire, and of the 
 fenny districts in general of the eastern side of England, in res- 
 pect to improvement, and of an improvement closely accom- 
 panied by a diminution of the diseases of Malaria, is so recent 
 and so familiar, that it is barely sufficient to name it ; while there 
 is not a peasant of those districts to whom it is not even better 
 known than to economists and physicians. 
 
 To notice here what has been the analogous history and the 
 corresponding progress of Holland, of Germany, and of France, 
 might afford some amusement to the reader ; but the detail would 
 Dot justify the space which it would occupy, while I was more- 
 over induced to mention some circumstances appertaining to this i 
 subject in a former chapter. It would be still more interesting j 
 to give the history of the improvements of Italy in this respect, and 
 more particularly of those which relate to the attempts on the 
 Pontine marshes in modern days. But from a mass of materials 
 so extensive, it is not easy to select and condense ; while the 
 whole, affording matter for volumes, might easily lead to the in- 
 convenient extension of an essay which it is my wish to retain 
 within moderate bounds, in hope of rendering it more widely use- 
 ful. 
 
 I shall now therefore proceed to remark, as connected with re- 
 medial objects, that while the drainage of pernicious soils|is often 
 a matter of great mechanical difficulty, as in the case of Holland 
 and Lincolnshire, or of other lands lying beneath the level of the 
 sea, so, as far as relates to the extirpation of Malaria, it is often 
 also but partially effectual. The diseases are diminished, it 
 true, but they still continue ; as is notorious with regard to oui 
 own fenny counties and to Holland, and as is no less evinced 
 while with a much more splendid but unhappy celebrity, by th^ 
 repeated failures or the very partial meliorations which have fol 
 lowed the exertions of the Papal government in Italy. 
 
 The chief causes of this imperfect melioration or partial failure 
 will probably be often found among the circumstances enume, 
 rated in the fourth chapter ; and it was partly with a view to thij, 
 object also, that the somewhat minute analysis displayed in tha^ 
 chapter wa3 made. To conduct a drainage for merely agricul 
 tural ends, is easy, or at least the mode and the result both, ar 
 obvious : to attempt the same for the purpose of remedying th j 
 insalubrity of any spot, be the character of that what it may, n 
 quires an intimate knowledge of every minute particular whic 
 may interfere with the expected result. Thus have I shown tfc 
 the pernicious spot needs not have the obvious character of 
 marsh, and that it may also be very limited, or even minute ; an 
 hence, that although an extensive tract of marsh is drained, an 
 
 
IN MALARIA. 87 
 
 sometimes even cultivated, there commonly remains something 
 which becomes a generator of disease. This is almost inevitable, 
 for example, in infra-marine fens, because the sea wall itself be- 
 comes a marshy focus of the Malaria. Still more is it inevitable 
 in this case, from the necessary existence or construction of 
 ditches, canals, or drains, almost unavoidably subject to alterna- 
 tions in the height of the water, and, in any case, even where the 
 marsh is more elevated, becoming the unavoidable receptacles of 
 that which is stagnant; while subject also in that case to varia- 
 tions of level, from the effect of heat, and thus forming petty 
 marshes of the worst quality. 
 
 I must depend on the information of others for what I have 
 never examined ; and if that be correct, then is it probable that 
 the pestiferous nature of the Campagna of Rome, inasmuch as it 
 docs generate Malaria, is, as I formerly remarked, more owing to 
 its ditches than to the soil itself, which in reality is dry, at least 
 in those seasons when the Malaria is most abundant and virulent. 
 And such also appears to be the truth as to some other parts of 
 Italy ; respecting which, I have found in books, much more fre- 
 quently than I could have expected, either a false description of 
 the facts or a fanciful explanation, or, lastly, an attempt to involve 
 the whole in mystery, as if the Malaria of that country was often 
 produced by inexplicable causes. And I may remark here gene- 
 rally, in aid of those who may have found themselves bewildered 
 in reading on this subject, that not only is this a common occur- 
 rence in the voluminous writers on Malaria, who are principally 
 also Italian ones, but that while, as far as my reading extends, I 
 have not found one luminous and philosophical view of the pro- 
 duction and propagation of this poison, and little which can even 
 serve the purpose of preventing diseases, so is it far too common 
 to find entire volumes filled with idle hypotheses, respecting py- 
 rites and volcanoes and mines, and attributing to electricity, aurora 
 borealis, magnetism, and similar visions, what the writers had 
 forgotten to seek in that which ought to have been obvious to the 
 most superficial and ignorant. I trust that it will now be found 
 a much more intelligible piece of natural history at least than it 
 has yet appeared ; and that what will be intelligible to all, will 
 also be followed by corresponding utility. To proceed. 
 
 Another analogous circumstance relating to the imperfect cure 
 of fens and marshes, here requires notice also, though I was com- 
 pelled to touch on it before when speaking of drainages ; because 
 I believe that it is a frequent cause of the persistence of the dis- 
 eases of Malaria when the great exciting causes have been re- 
 moved. There are not many marshy tracts where a perfect wa- 
 ter level can be expected, and, on the contrary, it is not uncommon 
 for them to be irregular, or to contain hillocks and depressions 
 
88 REVOLUTIONS AND CHANGES 
 
 
 or portions decidedly lower than the general surface. Here the 
 general drainage may be complete, or the land may even be cul- 
 tivated, while there will still remain swampy spots, or, as some- 
 times happens in high marshy grounds, small pools. Nor is it un- 
 usual for these to be overlooked, at least in our own country, as 
 of no pernicious efficacy ; particularly should they contain clear 
 water, and lie in a clayey or gravelly soil. Yet I have already 
 shown that even on dry lands, such pools do excite the diseases 
 of Malaria ; and should they be numerous or extensive after the 
 drainage of a tract of land, they may be sufficient almost to nul- 
 lify the effect of that, as far as the health of the inhabitants is con- 
 cerned. This, I believe, is also one of the circumstances occur- 
 ring in the Campagna of Rome, and it may aid in explaining the 
 insalubrity of that noted spot. 
 
 Having formerly noticed that Malaria is sometimes the produce 
 of low meadow lands, it will be obvious that when a marsh is 
 recovered to this state only, the cure of the evil may be imperfect; 
 a case not unfrequent in France, and which is much more likely 
 to occur in a hot than in a cooler climate, from the effects of 
 heat in the generation of this substance. And, as I was then 
 also obliged to point out, the cure of a marsh land is far more 
 likely to be efficacious when, after drainage, it is subjected to the 
 plough, than if it remained in grass ; with the exception, formerly 
 noticed, of the first breaking up. It is not only that the power of, 
 being cultivated proves the better drainage of the soil, but because 
 this species of vegetation has a greater tendency to evaporate wa- 
 ter and to prevent its accumulation ; while, from the removal of 
 the crop and the dryness of the stubbles, nothing remains from 
 which Malaria can be produced. And if what is said respecting 
 the rice fields of India be true, namely, that the poison is chiefly 
 produced by the roots and fragments left on the ground after re- 
 moving this crop, the remark is not an unimportant one, and may 
 be applied even to the case of corn lands of this nature in Euro- 
 pean climates. 
 
 I need not proceed further with this radical branch of the pre- 
 sent subject ; but those who may be interested in the question 
 may possibly deduce from it, hints as to the drainage of marsh) 
 tracts, in as far as one of the objects maybe the extinction ofdis 
 ease. Those hints relate to the number, position, and construe 
 tion of drains, and also of dykes ; and to the management of sucl 
 plashes or pools as may arise from the irregularity of the ground I 
 I cannot here enter into details, where every thing must be limit I 
 ed by expense, situation, and possibilities of various kinds ; an< 1 
 since the remedies have been indicated, those who are interests I 
 will be able to ascertain how far they are capable of application I 
 Let it be remembered always, that however human life may b I 
 
IN MALARIA. 89 
 
 despised in these cases, as being a mere political calculation, 
 the question of human misery or happiness is worth our atten- 
 tion ; while there may even be pecuniary interests concerned, 
 since the rent of such land will always be more or less regulated 
 by its salubrity, from many causes : and, in reality, there are some 
 situations where land even becomes subject almost to a minimum 
 rent, under a species of monopoly in the hands of the reckless or 
 profligate, or among those who, from habit, are enabled to exist 
 where competitors of another kind would perish or will not set- 
 tle. 
 
 That this is true, or rather that there are various circumstances 
 relating to value, whether as that regards labour or land, proper- 
 ty or rent, which are materially affected, or regulated, by the sa- 
 lubrity of lands or localities, would be easily proved by a statisti- 
 cal selection of facts from various countries ; while the results 
 would even surprise those who have not been accustomed to con- 
 sider this subject, or are in a state of defective information re- 
 specting it. It is a question, however, on which it would be te- 
 dious to enter ; but if it is one which amply deserves the attention 
 of landholders, even now, it is one also of which the importance 
 will become more sensible as the knowledge of this subject is ex- 
 tended, and as it becomes better known that the health of indivi- 
 duals, as well as the public safety, is often materially in the hands 
 of landowners. 
 
 Where the principle of evil is so simple, the theory of the reme- 
 dy is at least equally so, whatever may be the fact as to the prac- 
 tice. Sea walls ought not, for example, to be allowed to become 
 marshes or gardens for reeds ; ditches and drains ought to be kept 
 clean ; while receptacles of water should be laid dry, by a drain- 
 age into the general conduit. Could every bank, whether of dyke 
 or ditch, be a stone wall, for example, the remedy would be near- 
 ly complete, as far as relates to those : and such a w T ork approxi- 
 mates nearest to that, when it is of earth, or is free, as far as pos- 
 sible, from vegetation. 
 
 These, and many similar regulations, are almost too minute to 
 be within the power of governments, even where they have be- 
 stowed the greatest attention on the general subject. Yet they 
 were compulsory in the days of ancient Rome ; and where the 
 state still holds in its hands those laws without which the greater 
 improvements of this nature cannot be conducted, it might regu- 
 late ; while its enactments would tend at least to diffuse the ne- 
 cessary knowledge as to other cases. Yet as far as our own coun- 
 try is concerned, the state, and the poeple both, must first be con- 
 vinced that such improvement of the public health is possible, and 
 that the diseases attributed to Malaria in France and Italy, are ac- 
 tually produced by the same cause in England. That they were 
 
90 REVOLUTIONS AND CHANGES 
 
 once thus produced, I have proved in the preceding chapter; be- 
 cause the diminution of disease, keeping pace with the improve- 
 ment of wet lands, proves the cause. The same diseases exist, if 
 in less numbers ; the climate is at least as warm as it was : and 
 why then arc they not still produced by the same causes ? cor- 
 respondently diminished, but here proved to be unconquered. 
 England was not formerly exempted from Malaria ; and on what 
 grounds does it claim exemption now, when it possesses all the 
 circumstances necessary for the production of that poison? 
 
 To proceed; and to the reverse case; it is plain that wherev- 
 er a tract of dry land has been converted into a marsh by inun- 
 dation, whether from a breach of the sea or the overflowing of ri- 
 vers, we must expect an event the opposite of the preceding, or 
 the production of this poison where it was before unknown. I 
 need not dwell on a subject so obvious ; but the history of all 
 lands is full of events of this nature, even on a great scale ; while 
 on a smaller one, if often overlooked, it is a frequent occurrence, 
 even in our own country, from the inundations of rivers, even 
 where the effect is far short of producing a swamp : being often 
 the neglected cause of what are popularly called sickly seasons, 
 in certain districts of England, as might easily be proved by a re- 
 ference, to facts in great number. 
 
 Whatever revolutions in the production of Malaria, whether as 
 to its absolute generation, increase, diminution, or disappearance, 
 may occur from alterations in lakes, whether these consist in their 
 increase, diminution, or drainage, they will be so easily explained 
 from the general principles, that it is unnecessary to dwell on them. 
 If it would be abundantly easy to adduce specific facts in proof, 
 from foreign countries, it cannot be necessary ; but I may quote 
 one instance among ourselves, of the complete extirpation of Ma- 
 laria by the drainage of a very small piece of water : and it is 
 worth quoting, as equally proving a then almost unsuspected 
 cause and its remedy. This was the North loch of Edinburgh ; 
 formerly noted for producing agues, which, since the drainage of 
 that spot, have disappeared. And even the insignificance of this 
 spot renders it a valuable example, as proving how very small a 
 body of water is capable of being a permanent source of the dis- 
 orders of that nature, even in a climate so little favourable to the 
 production of Malaria as is'that of Edinburgh. They who know 
 what the North loch was, must be incredulous indeed, if they do 
 not admit that what occurred there, must be common every 
 where ; and it would be somewhat difficult indeed, even from this 
 sole evidence, to point out the pool in England which should not 
 he a cause of fevers. 
 
 There is little doubt that the state of the Malaria in the neigh- 
 bourhood of the great American lakes, is undergoing chances 
 
IN MALARIA. 91 
 
 from the alterations that take place along their shores ; but there 
 are no observations as yet on which we can rely as to the fact it- 
 self, or at least I have inquired for such information in vain. And 
 if I may put an eventual case, it is easy to see that when, at some 
 future, if far distant day, the fall of Niagara shall have ceased to 
 exist, from the wearing backwards of the bed of the river to its 
 own lake, such an entire revolution will take place throughout 
 this whole chain, as cannot fail to be attended with marked con- 
 sequences as to their Malaria, be those results what they may. 
 
 It is much more easy to ascertain the alterations in the pro- 
 duction of Malaria which arise from the vacillation in the extent 
 of lakes dependent on the changes of summer and winter ; most 
 conspicuous in those which, like our Whittlesea mere, are formed 
 in flat lands. Unquestionably, the heat of summer itself would 
 increase the production, though the size of the water should re- 
 main unaltered ; but there* is a great accession to the evil pro- 
 duced by the tracts of marshy land which are laid bare by its 
 recession, as well as from the exposure of the muddy bottom, as 
 formerly discussed. This effect takes place most unquestionably 
 in Switzerland, and much more notedly in Italy ; while, in Sicily, 
 among other spots, the Lake Biviere, sufFering a loss of two-thirds 
 of its dimensions in summer, is a conspicuous example ; as is the 
 lake or pool at Cagliari in Sardinia, where the fevers, thus pro- 
 duced, are noted among the most notorious in the Mediterranean. 
 It appears also to be true of the Caspian sea ; and to an enormous 
 extent, along the whole of its expanded shores ; but, what must 
 interest us more, it is a very palpable result of the diminution in 
 summer, of our own smaller ponds and pools, the poisonous 
 qualities of which were formerly noticed. 
 
 And this also may explain, perhaps entirely, what has hitherto 
 appeared obscure v respecting the disorders generated by the Ma- 
 laria of these narrow spots, and the seasons in which they are 
 active ; while by examining those particulars more closely, I shall, 
 to what 1 formerly said, add further proof that they are causes of 
 disease, however that may be doubted or denied. If they do not 
 so often produce disorders in spring as in autumn, or if, caus- 
 ing ordinary fevers, they do not give rise to intermittents, it is 
 not solely from the differences of season, or heat, but from dif- 
 ferences in their relative conditions at those seasons ; while thus 
 also it is, that they more rarely generate simple and original in- 
 termittent, as this is chiefly a disorder of spring. And I think 
 this point so important, from the immense number of these mi- 
 nute spots of water which are found all over England, and from 
 the utter ignorance or want of suspicion respecting them, that I 
 must be excused for urging it; particularly, because, in many 
 places, and in the neighbourhood of London especially, it is usual 
 
92 REVOLUTIONS AND CHANGES 
 
 to leave such pools in excavating for gravel, even on the populous 
 commons in its vicinity : diseases being thus sometimes brought 
 among a population where they were formerly unknown. But 
 if no ague is generated, or if at least this is rare, and if the con- 
 sequences are hence denied, the solution is easy. In the spring, 
 these pools are commonly full to the very margin ; while, very 
 generally, the steep gravelly banks exclude any vegetation, as the 
 depth of the water, or other causes, prevents also the growth of 
 aquatic plants. But as summer advances, the water subsides, a 
 vegetation encroaches on the borders, the purely aquatic vege- 
 tables begin to flourish and die, and, in the autumn, these spots 
 are so many petty marshes; often also exposing muddy shores or 
 bottoms to the action of the sun, and then producing the fevers 
 which are attributed to the heat of the weather, to fruit, or to 
 any other cause but that which is the real one ; and which might 
 often be prevented or remedied by a different management, such 
 as to prevent the lodgment of water: a proceeding which ought 
 to be rendered a regulation of the police, by every parish at least 
 where such operations are permitted. 
 
 In speaking of marshes, I was compelled to notice the increase 
 of Malaria produced by inundations of the sea and of rivers ; and 
 I might then have added, that the alluvial plains traversed by ri- 
 vers, although they should be otherwise not unhealthy, are fre- 
 quently rendered so by that common operation, the transference 
 of the stream, or the formation of new channels. The effect of 
 this is, in fact, to produce swamps and pools, in ground before 
 dry ; changing them also, in successive seasons, or after new al- 
 terations of the stream, from one point to another ; and with in- 
 jurious consequences far too notorious as to the Asiatic and Ame- 
 rican rivers at least, to admit of doubt. 
 
 This is a very frequent occurrence, in particular along the course 
 of the Ganges and the Burhampooter , and, in Bengal, it is in re- 
 ality one of the principal sources of the fevers which are so often 
 the cause of extensive epidemic mortality in that country. I have 
 here pointed out casual inundations, leaving consequent pools or 
 marshy spots, as being here, and elsewhere, an ordinary and al- 
 most an annual cause of disease ; but this permanent change of 
 channel is also one of great extent and importance ; the deserted 
 reaches becoming lakes or pools, which are filled by the rainy 
 season, to be again laid dry ; and which, at length, as vegetation 
 begins to accumulate in them, form marshes, or swamps, and jun- 
 gles, of the same character, and perhaps even more pestilential. 
 
 Of the consequences arising from simple inundation, Egypt, as 
 already remarked, produces a familiar example, since its season 
 of fevers commences with the subsidence of the Nile ; and thus 
 also, at Bassorah, the same effects, and to a highly destructive de- 
 
IN MALARIA. 93 
 
 gree, are produced after the overflowings of the Euphrates. This, 
 or the letting loose the river, it is related, is a common mode of 
 revenge on the inhabitants of that town, adopted by the Arabs ; 
 while it is said that, on one occasion, 14,000 people perished in 
 consequence. In Italy, from a similar cause, or, by the breaking 
 loose of the Foglia in 1 708, a bad epidemic was the consequence 
 at Pesaro ; and the same events have frequently followed the in- 
 undations of the Rhone, at Villeneuve St. George, Avignon, and 
 elsewhere, as has also happened in Normandy, in the commune 
 of the Greverie, from the inundation of the Vire. Similar occur- 
 rences are related of Silesia ; nor should I here forget that a noted 
 and destructive fever was the consequence at Rome, from an in- 
 undation of the Tiber, in 1695. With respect to the Danube and 
 the Don, the facts and the results are far more common, and in- 
 finitely more notorious ; but I might, without difficulty, extend to 
 any length, a class of illustrations which it cannot be necessary 
 to pursue further. 
 
 But there is a class of phenomena belonging to rivers, so intri- 
 cate in its nature, and so important in its consequences, as to re- 
 quire a more minute notice ; while it concerns all countries, and 
 our own among others, much as it is, like all else, overlooked or 
 unsuspected. The state of things to w T hich 1 here allude is also 
 a steady cause of the progressive increase of Malaria ; affecting 
 almost every river of the world, and further, proceeding, as to the 
 whole globe, in an accelerating ratio, so as to lead to a constant 
 augmentation and extension of diseases, unless where it is coun- 
 teracted by other causes, natural or artificial. If, as relates to 
 the Thames, I have reserved a notice of this fact for the next 
 chapter, I cannot avoid speaking of it here, belonging, as it espe- 
 cially does, to the matters under review. 
 
 Every river which, by bringing down materials from the moun- 
 tains and propelling the sea, has formed flat tracts of land, such as 
 the great plain of Bengal, or those of the Oroonoko, and the Mis- 
 sissipi, with thousands more of less note and on all scales of di- 
 mension, must sometimes rise above its ordinary banks, causing 
 inundations. Thus, when incommoding the adjoining lands in 
 agricultural countries, it is embanked by art ; while, in conse- 
 quence of this process, the alluvial matters which would be dis- 
 persed over large spaces, from those changes of direction whence 
 the plains themselves are formed, become confined in the channel 
 itself; depositing within a narrow space on its bottom. Thus 
 they tend to raise the water in its bed, and, consequently, to cause 
 it, on any increase, to overflow, still more certainly, the lands 
 around. And as this effect is the very consequence of the em- 
 bankment, so, at any given point, the bank must be made to keep 
 pace with the rise of the channel, that the restraint may be effec- 
 
 N 
 
04 REVOLUTIONS AND CHANGES 
 
 tual and constant. Hence as the river becomes more elevated, 
 the ultimate result is the same as if the surrounding lands had 
 been depressed to the same amount: and thus, while the stream 
 which drained them once can drain them no longer, they become, 
 first, meadows, and ultimately marshes. And if, in the former 
 condition, they can still be drained by means of canals and flood- 
 gates, this process becomes in time inefficient, and recourse must 
 be had, as in Holland, to lifting machinery. 
 
 Now, as the same process takes place at every point along the 
 course of the river, the embankment must also be extended fur- 
 ther upwards towards its source ; or, while there is a necessity 
 for elevating the former bank every where, so a new one becomes 
 required where there was none before. Thus, the including lands 
 which did not formerly demand any drainage, begin to require it ; 
 or that which was dry land becomes meadow, the meadow be- 
 comes a marsh, and the marsh a swamp or a pool. And thus, 
 throughout the whole process, does disease increase. The new 
 land, as formed by nature, will be a focus of fevers : and hence a 
 constant augmentation and extension of disease throughout the 
 world, proportioned to the formation of new lands, whether na- 
 turally wet or rendered so by embankment. 
 
 Such is the analysis of this particular cause of the revolutions 
 of Malaria, a revolution of augmentation but too commonly ; 
 while, if the examples would be abundantly easy to produce, 
 their very numbers render that unnecessary. But, reversely, in- 
 salubrious tracts of land may be rendered healthy, or the pro- 
 duction of Malaria is diminished, by natural changes in the 
 courses of rivers ; and in different modes. It may chance, for 
 example, that the breaking loose of a river may inundate a tract 
 of marshy land, or convert into an innoxious lake that which was 
 a poisonous swamp ; since, to inundate by whatever means, provi- 
 ded the operation be effectual, is to destroy the very sources of the 
 poison. In another, and in the opposite mode, it is easy to con- 
 ceive how a change in the channel of a river may lead to the drain- 
 age of a marshy tract : but there is one case of melioration, in the 
 instance of rivers, which is progressive, as it is also extensive ; ope- 
 rating over the entire world, and counteracting that very increase 
 of disease from the formation of alluvial lands, which I have just 
 been describing. If the first effect of the deposition of alluvia, is to 
 form a marsh where the river meets the sea or a lake, and if such 
 tracts are gradually extended by the same operations, the succes- 
 sive deposition of new alluvia, while it may push forward a fur- 
 ther marsh, raises that which was last formed, or converts the 
 marsh into a meadow, and, successively, the meadow into dry 
 land ; the remedy thus going hand in hand with the evil. Thus 
 it also often happens, under favourable circumstances in the de- 
 
IN MALARIA. 95 
 
 clivity of the shore, that no further marsh is formed, or the reme- 
 dy becomes complete. And hence if, in some places, there may 
 be a progressive augumentation of disease through ages, there are, 
 in others, progressive amendments, or an entire removal of that 
 source of pestilence which had once existed. Thus we learn to 
 explain the rerolutions for the better which have occurred with 
 regard to the popular health in certain situations in our own 
 country, in France, and perhaps more distinctly in Italy, the fer- 
 tile parent of examples in every thing which belongs to the na- 
 tural history of Malaria. 
 
 Such geological changes are the chief causes of those revolu- 
 tions in the public health which, from the testimonies of history, 
 have occurred, since the classical times, in Italy, and probably in 
 Greece; of which I have had occasion to allude to some, in dif- 
 ferent parts of this essay. Fundamental, at least, they are ; what- 
 ever other causes, of an agricultural nature chiefly, may conspire 
 with them, or whatever art may have effected in diminishing the 
 produce of Malaria, or unintentionally, in augumenting it. And 
 that they have scarcely ever met the attention which they de- 
 serve, in either case, is most apparent in all that has been written 
 on this subject ; while we must often be surprised at the modern 
 neglect of what seemed to have been most accurately studied by 
 even the remoter ancients. It is further plain, that in many cases 
 where rivers are concerned, the sea must also be an agent in the 
 production of all such revolutions. It is by a joint action of the 
 sea and the river where the meeting occurs, that the alluvia are 
 distributed ; and that distribution may be such as to produce 
 either evil results or good ones. In the lagunes of Venice, as I 
 have elsewhere remarked, the effect is good ; or the sea carries 
 off the alluvia which would otherwise form banks of pestiferous 
 mud : in the Pontine marshes, it appears to be the reverse ; but 
 amid so many complicated effects as must occur in all these cases, 
 it would be tedious to describe all that does or may happen at the 
 collision of rivers with the sea. 
 
 But even without the aid of rivers, revolutions in the produce 
 of Malaria take place in many countries, from casual events, or 
 from that change of the mutual level of the sea and land, which 
 geology ascribes to the subsidence or elevation of the latter; an 
 alteration of level which appears to be connected with the cause 
 of earthquakes, and which has, on various occasions, operated so 
 conspicuously in Italy, in both directions, and in some cases, in 
 both alternately, as at Ravenna and near Naples. How marshy 
 land might thus be laid day, or dry land be rendered marshy, is 
 sufficiently apparent ; while both these effects have, at different 
 times, occurred at the very place which I have named, Ravenna, 
 as in other parts of the Adriatic, and on the Mediterranean shore 
 
96 REVOLUTIONS AND CHANGES 
 
 of Africa ; having, doubtless, been attended by changes in the sa- 
 lubrity of those districts. 
 
 That casual irruptions of the sea have produced revolutions of 
 the same nature, both for good and for evil, and on several con- 
 spicuous occasions, is well known. In these cases, the inundation 
 has either extirpated disease by covering a marsh, or has excited 
 it by rendering dry land marshy ; while, reversely, the retirement 
 of the sea, has also, from acting in different ways, produced both 
 the effects in question. Holland, and the shores of the Baltic in 
 general, can produce historical testimonies in abundance as to 
 these points ; while epidemic seasons of dreadful celebrity, and 
 even of perennial continuance, have often arisen from such inun- 
 dations. Our own Lincolnshire will furnish other examples ; and, 
 doubtless, could we know the truth at present, the loss of the 
 Goodwin lands by inundations proved the remedy, expensive as 
 it was, for a wide tract of poisonous marsh. That the Persian 
 gulf also produces examples of the same nature, and to a terrific 
 extent, appears from the writings of many travellers ; if the spe- 
 cific facts have not been accurately distinguished. 
 
 Of seasons of mortal epidemics, produced by eruptions of the 
 sea, Calabria, under its earthquakes, furnishes examples even 
 more notorious than Holland and Denmark; and the minor 
 changes to whicli I have been alluding, will probably explain 
 most of the apparent mysteries which relate to the history of the 
 revolutions of Malaria on sea shores ; among others, the unexam- 
 pled present condition of Civita Vecchia, that of Carthagena in 
 Spain, and those of several places at the mouth of the Rhone, so 
 different in point of salubrity now, from what they were in the 
 times of the Romans ; changes which, in some cases, as combined 
 with greater facility or new modes of propagation, have often ex- 
 tended their influence very widely. 
 
 There is yet one fact connected with those revolutions in which 
 the sea is concerned, which has often been of great efficacy, 
 though more frequently in diminishing than increasing the produc- 
 tion of Malaria. This is the sand inundation, conspicuous on the 
 shores of the Baltic and in Holland, as well as in Italy and France, 
 and on the African shore, and sufficiently remarkable in many 
 places in our own island. By this, marsh land is not only raised, 
 but covered and dried ; and thus have many poisonous tracts been 
 remedied in the countries which I have named. That, in some 
 situations however, the sand flood has produced evil instead of s 
 good, is most certain; by forming external bulwarks, and thus 
 retaining the land water in the form of marshes or lakes ; an event 
 of which our own country presents many examples, though on a 
 small scale. 
 
 If I recollect aright what I have not seen for many years, it 
 
IN MALARIA. 97 
 
 would be easy to comprehend the nature and action of many of 
 these circumstances, as far as the sea is concerned, by an inspec- 
 tion of the connected shores of Sussex and Kent, which I select as 
 j an example out of many others, because it is well known. A geolo- 
 | gist at least, would have no difficulty in seeing, here, where a per- 
 j nicious surface has been produced and where it has been reme- 
 died; and how both these effects have resulted at different points, 
 j from similar or opposed operations, or how that very change 
 \ which has amended one spot has disordered another. Hence, in 
 j practice, have arisen those alterations in the salubrity of many of 
 | the situations on the English coasts, sometimes for good and some- 
 | times for evil, which are well known to the residents, if they are 
 j seldom able to account for them, and therefore often view them 
 j as of a mysterious nature. 
 
 I may now proceed to remark, that to remove a Malaria by 
 inundating land which cannot be drained, will always be a very 
 compound question ; and if I cannot just now quote a case of such 
 an experiment, either successful or otherwise, it is a proposal 
 which has long been debated in Dominica, respecting that flat 
 tract of mangrove in Prince Rupert's Bay, which is the demon- 
 strated cause of the frequent and severe mortalities of this ill 
 chosen spot. How obviously necessary it is that in such an ope- 
 ration, the inundation, whether by means of fresh water or of the 
 sea, should be accurate and steady, 1 need not say ; since it is 
 plain that an ineffectual operation might aggravate the evil which 
 it was intended to remedy. 
 
 The last of the revolutions of Malaria, as to increase or de- 
 crease, depending on alterations in the soil, is that which belongs 
 to woods ; but it is a question which chiefly concerns the inter- 
 tropical or hot climates. The principle of judgment in this case 
 is as easy as in any other, from considering the causes of the Ma- 
 laria. The woods which produce it in those climates, are the 
 close and marshy forests or jungles ; and as these can scarcely be 
 j affected but by destruction, it is only by eradicating or burning 
 i them that the diseases which they produce are extirpated. Thus 
 I it is, that as the increase of population produces this consequence 
 j in all woody countries, the natural effect of clearing the ground 
 | for cultivation, is often also the cause of the diminution or extir- 
 | pation of fevers ; while I have formerly shown how the very re- 
 ! verse effect sometimes takes place. If other reasons, sufficiently 
 j easy to judge of, conspire, this is at least a fundamental cause of 
 | the improvement of the health of the people in new countries. 
 Thus also is it, reversely, that when, in consequence of famine, 
 destructive wars, impolicy, or bad government, agriculture and 
 population diminish, the diseases of such climates increase, even 
 in an excelling ratio, from this cause among others ; as the vigour 
 
\)\) REVOLUTIONS AND CHANGES, &C. 
 
 of vegetation soon restricts the once opened soil, to restore it to 
 Bomewhat like its original state of thickets and forests and neglect. 
 It is not poverty and famine alone which are the causes of the in- 
 crease of disease in these cases, though such is the explanation 
 commonly given and received. The rude land gradually en- 
 croaches on the cultivated : if pasture succeeds to agriculture as a 
 more manageable economy, if drainage or embankment is neglect- 
 ed, if rivers break loose and marshes replace what was meadow, 
 so do forests and thickets and jungles rise and spread, and as man 
 becomes weaker, nature becomes more powerful ; reclaiming her 
 rights, and bringing calamity and disease upon neglect and pover- 
 ty. We have but to look at the Turkish states to see how truly 
 this is the picture of the country which that ignorant and stupid 
 government rules, if rule it can be called, but to destroy. 
 
 The remedies, in this particular case, often concern us, as 
 colonists, most seriously ; and they are easily deduced from the 
 general principles. To destroy such forests and woods where 
 they exist, to prevent them from increasing, and to do all this by 
 occupying the ground in another manner, form the remedy and 
 the prevention both ; while, fortunately, it is a remedy which in 
 general amply repays its expense, in the augmentation of useful 
 produce and population. It is true that there are cases, even in 
 our own possessions, where this is impracticable, from mechan- 
 ical or local and physical difficulties, no less than from the irre- 
 pressible vigour of vegetation, and, further, from the useless or 
 inapplicable nature of the fundamental soil, as well as from defi- , 
 ciency of population, or want of demand for the produce. But i 
 there are some, in which we must perhaps blame the policy or i 
 the councils of our colonial governments, for neglect of what they > 
 might sometimes remedy with very little difficulty. 
 
 For India and its councils there is however an ample excuse 4 
 as to this subject, great as are the evils produced by its uncleared 
 lands ; while there appears no want of conviction as to the ex- 
 tent and nature of the evil or its cause, or as to the only remedy, i 
 The magnitude of the evil could not possibly, in fact, have been, 
 overlooked ; having been almost the destruction of armies, andi 
 sometimes more exterminating than all the collision of actual war. 
 The difficulty, it must be admitted, is considerable, if it is noti 
 absolutely insuperable ; as it consists in no less than determining! 
 that obscure and most complicated question under our supreme: 
 government, namely, where the real title to the lands lies. The 
 destruction of jungles, and, with that, the diminution of fevers, 
 with the consequent augmentation of agriculture, may be but 
 partial motives, perhaps, to an investigation and settlement which 
 shall set this point at rest ; but, added to all the other inconveni- 
 ences which attend this unsettled condition of property, they mav 
 
ON THE PROPAGATION OF MALARIA. 99 
 
 be expected to assist in stimulating the councils of India to an 
 effectual exertion, whenever an opportunity, not probably to be 
 commanded, shall occur. But to terminate a subject which, by 
 means of local references, might be converted into a volume, I 
 may now add, that whatever other revolutions may occur in the 
 influence of Malaria, they are dependent on its propagation ra- 
 ther than on its production, and will therefore be deduced, with- 
 out any formal enumeration, from the statements forming the 
 next chapter. 
 
 CHAPTER VII. 
 
 On the propagation of Malaria. 
 
 To ascertain all the circumstances under which Malaria is gene- 
 rated, is most obviously the essential part of every philosophical 
 inquiry into this subject; and while, as it is here, in its very 
 germs, that it may most effectually be checked or eradicated, this 
 also is the question which chiefly concerns the people or their 
 governments. But the propagation of Malaria occupies at least the 
 place of next importance in the philosophy of this subject ; while, 
 though often far less under our regulation or controul, we are not 
 absolutely powerless in protecting ourselves from the diseases of 
 which it is the cause, by diverting or impeding it. To know the 
 remedies, it is first however necessary to make ourselves acquaint- 
 ed with the facts ; to investigate all the means by which, and the 
 circumstances under which, it is propagated. 
 
 Here too I must regret that a deficiency of information disables 
 me from giving that regular analysis and detail of those circum- 
 stances, without which philosophy ought never to be satisfied. 
 The observations of any individual on such a subject must be 
 narrow, and my own have been peculiarly impeded ; while in 
 seeking for information, whether published or oral, there is so 
 little of fact to be extracted from mountains of rubbish, and so 
 many obscurities and contradictions after all this is done, that, 
 when the labour is gone through, the whole is little better than a 
 tract intersected by wide chasms, or a collection of fragments. 
 
100 PROPAGATION OF 
 
 Hereafter, it must be hoped that whatever is here defective will 
 lead to that truth, the arrival of which was never yet accelerated 
 by conjecture or confident falsity ; or by those plausible expres- 
 sions and terms, which too often pass for ideas. 
 
 Whatever Malaria may be in its simple state, it js only as united 
 to the atmosphere that we know it ; and we must therefore view 
 it as an aeriform fluid, as far as the question of its propagation is 
 concerned. It must indeed be considered as the very atmosphere 
 itself, where it exists ; and its propagation therefore must be pri- 
 marily regulated by those laws which govern the motions of cur- 
 rents of air. 
 
 Here, unfortunately, occurs our first and fundamental difficulty ; 
 for we know nothing, in reality, of those laws. The theory of 
 the winds is one great obscurity ; the limited, internal, and less 
 remarkable motions of the air, are, if possible, a subject of still 
 greater darkness. Thus it is that we can predict little respecting 
 the propagation of Malaria through the agency of currents of air, 
 and are compelled to judge locally by local observations, or by 
 experience which we cannot transfer to other localities. But as 
 this substance, whether gasiform or not in its origin, is probably 
 a compound, whether mixed with the air or dissolved in it, or in 
 some state of chemical combination, it must be subject to chem- 
 ical laws as well as to those mechanical ones which regulate the 
 motions of aeriform fluids. 
 
 And though the chemical constitution of atmospheric air is con- 
 stant, as far as we at present know, the atmosphere itself is a 
 variable substance ; since, to its three radical elements, is added 
 water, varying in quantity, and probably also in the condition 
 which it holds as to the essential ingredients. And, since the 
 matter of Malaria is united to this variable fluid, that union may 
 be more perfect, or more abundant in one condition of the air 
 than another, while there may also be conditions in which it will 
 not combine at all. Thus also may that union be affected by 
 variations of temperature ; while we can further conceive it ca- 
 pable of being decomposed or destroyed by actions, however un- 
 known their nature is to us, connected with certain conditions of 
 the atmosphere. 
 
 Thus the propagation of Malaria from its generating source, 
 may be influenced by variations dependent on these causes ; it 1 
 may be produced in abundance, but the existing atmosphere may 
 be incapable of absorbing, or of conveying it, or else it may be 
 destroyed by the union ; and hence our expectations may be dis- 
 appointed when we reason solely on its mechanical propagation. 
 And it is probable, by analogy, that this is true ; while the eviden- 
 ces from fact, will find their place shortly. Thus, certain states 
 of the atmosphere, independent of motion, and therefore probably 
 
MALARIA. 101 
 
 chemical, are found to dissolve and communicate contagion better 
 than others ; while there are also conditions in which it seems to 
 die, or is not propagated at all. Thus it is, also, familiarly, with 
 regard to odours ; and very notedly with the odour of flowers, 
 and with that general vegetable perfume which fills the atmos- 
 phere of spring and early summer. 
 
 I have said that Malaria was probably a compound substance ; 
 an inference drawn from the mode of its production, and from its 
 analogy to contagion ; and the compound nature of this latter 
 substance, is proved by the facility with which it is destroyed or 
 decomposed under new chemical agencies. This is not so well 
 demonstrated respecting Malaria ; that is, by direct chemical ex- 
 periment; but the fact can scarcely admit of doubt, when we 
 know that it never penetrates certain atmospheres which are im- 
 pure or charged with foreign ingredients ; as will be pointed out 
 hereafter. We can scarcely therefore err in assuming the chem- 
 ical destruction of Malaria as a law concerned in the phenomena 
 belonging to its propagation. 
 
 But there is yet a fact concerned with this, which appears indis- 
 putable, though our knowledge of the nature of Malaria does not 
 enable us to give its theory. This is, that it is capable of being 
 attached to certain solid substances ; to vegetables for example, 
 and, possibly, to the soil itself. I use the word attachment rather 
 than union, though even that term is perhaps too strong ; but 
 whatever the relation be, it seems to possess an analogy to the 
 case of the matters of contagion, in which an absolute and dura- 
 ble union takes place with many solid bodies, as if they were 
 themselves solidified in the substances. The difference however 
 in these two cases is, practically, of great importance ; as there 
 is no evidence that the matter of Malaria is thus durably attach- 
 able and transferable, any more than that it is regenerated through 
 the medium of a diseased body, as contagions are. Were the 
 plague indeed the produce of a vegetable Malaria, as has been 
 supposed by some persons, then would one of its varieties at least 
 be as attachable as contagion ; while it would also be reproduci- 
 ble by the animal actions. Were any remitting or marsh fever, 
 decidedly originating in Malaria, capable of similar reproduction 
 and transference, as has been said, this would form a material ad- 
 dition to the object of this inquiry ; but whatever the controver- 
 sies may have been on this question, the opinion has not been es- 
 tablished ; while it is a dispute appertaining to the medical por- 
 tion of this work. 
 
 The way seems now cleared, as far as it can be at present, for 
 examining into the facts which relate to the propagation of Mala- 
 ria ; and the first, as the simplest case, is that of proximity. The 
 place in which it is produced, or that which is nearest, ought to 
 
 O 
 
102 PROPAGATION OF 
 
 sutler most from its action ; it being also presumed that the at- 
 mosphere is at rest. And that this is the fact, with some excep- 
 tions to he hereafter noticed, consists with all experience. Hence 
 it is that residence on or near a marsh is injurious or hazardous ; 
 while, in the case of more narrow spots, it is probable that such 
 absolute contact or immediate vicinity may even be necessary to 
 the action of the poison, since a small distance may render its 
 power null by dilution. And it is both reasonable and consistent 
 with experience, to measure the danger, whether as to effect, or 
 power of propagation, by some ratio derived from the magnitude 
 of the pernicious soil, or the quantity of Malaria generated. 
 
 If the general experience of all countries confirms this view of 
 the danger of proximity, it is strikingly proved by the practice of 
 Italy in former times ; attentive to this subject as it appears to 
 have been, even from the earlier periods of the Roman power. 
 Hence it is, that so many of its ancient towns are situated on hills ; 
 while, in spite of the opposite practice in the foundation and 
 growth of Rome, it is evident, from the Roman statistical writers, 
 as I have shown, that they were fully aware of the evil, and of 
 the value of this remedy. 
 
 It ought to be superfluous to ground upon this simple fact, cau- 
 tions or advice respecting the choice of places, whether for towns, 
 or houses, or encampments : yet we see that this has been over- 
 looked or despised, in uncountable instances ; not only in former 
 times but in recent ones, in our very days, and in all countries. 
 If ignorance may often be permitted to excuse itself for the origi- 
 nal error, there are abundant cases where there is no excuse for 
 having continued to build and remained to die, through genera- 
 tions. Rome perhaps became too gigantic during its period of 
 ignorance, to be afterwards abandoned or transferred : but there 
 was no apparent reason for perpetuating Calcutta, when, from the 
 very hour almost, of its foundation by'Charnock, its destructive 
 situation had been demonstrated. That Holland should have per- 
 sisted in inhabiting that Batavia which it had studied to render 
 even more poisonous than nature had already done, by the model 
 of its own pestiferous fatherland, is a problem which Holland 
 must be allowed to explain as it best can. 
 
 It must be presumed that ignorance, as often as convenience, 
 will also be the defence of Spain respecting the Havanna, Vera 
 Cruz, and so many more of its American settlements ; where, in 
 some cases at least, death seems to have been courted, and where 
 a little thought at first, or a little resolution and sacrifice after- 
 wards, would often have avoided the evil. Thus also may France 
 defend its ancient towns of Nantes, Rennes, Dol, and many more 
 in the north, with others in the central and southern parts, be- 
 yond numbering : by the plea of ignorance added to that of ne- 
 cessity; while, for Holland, throughout, necessity is a para- 
 
MALARIA. 103 
 
 mount plea. But the example and the knowledge of Italy were 
 open to the whole world ; and as little was medical and statisti- 
 cal information in such a condition as to have admitted any ex- 
 cuse for St. Lucie and New Orleans ; as for endless other settle- 
 ments, equally ill chosen, in almost every European colony and 
 conquest throughout the world. 
 
 But not to extend examples of this nature, it must be admitted 
 that convenience and necessity often produce strong pleas in fa- 
 vour of a bad choice, or of a persistence in the original bad choice 
 of the enemy whose ground has been occupied. Situations of 
 this pernicious nature, are often the most fertile and the most 
 populous, they are often convenient maritime posts or sea-ports, 
 and they are often the strongest and the most defensible places. 
 But there is often also a choice, without losing all these advan- 
 tages or encountering all those evils ; while, unfortunately, it has 
 seldom appeared as if the uncertainty of human life, and the quan- 
 tity of human suffering, ought to enter into the political calcula- 
 tion. Yet even on the views of public economy, this is a ques- 
 tion deserving of consideration. Human happiness is, after all, 
 the end and object of all this conquest and commerce ; and in 
 acting thus, we surrender the object of pursuit in pursuing it. 
 Nor is the security of life less necessary to profitable industry, 
 than security of property ; while, in this case, the legislating foun- 
 der of a colony professes to ensure by direct laws, what he de- 
 stroys by the very roots. And thus also does it follow that, on 
 security of life, depend, mainly, morality and good conduct ; since, 
 in human history, it is a noted truth, that the maxim " let us eat 
 and drink for to-morrow we die," becomes, in such Batavian sit- 
 uations, the too common rule of a loose life. Were it necessary 
 to prove our own neglect on this subject, I might quote, what I 
 now may with safety, Prince of Wales's island ; but I am more 
 pleased to pass from such questions. 
 
 If I have here dispersed the remarks on the remedial processes 
 against Malaria, by bringing them into juxta-position with the 
 particular circumstances to which they are applicable, it was that 
 I might avoid the repetition which must have followed the allot- 
 ment of a separate chapter to them ; though producing thereby, 
 inconveniences, I hope, of less weight. And I must therefore in- 
 troduce here a few further remarks on this subject as it relates to 
 military proceedings ; though I must divest them of much of their 
 authority, by suppressing whatever, as belonging in particular to 
 recent facts, might give pain to some one. The bare suspicion 
 of intending censure should be avoided, where the sole object 
 has been, by means of facts which ought to be considered as mere 
 evidences, to inculcate useful knowledge and prevent further evils. 
 It is impossible to say what will be right without observing what 
 
104 PROPAGATION OF 
 
 has been wrong; to correct error without pointing out error, to 
 produce evidence without examples. Had there been nothing to 
 blame, this essay would never have been written ; for there 
 would have been nothing to teach. 
 
 It is a general observation which applies to all cases as well as 
 the present, that in addition to the evils which Nature herself has 
 inflicted on us, in the production of Malaria through unavoidable 
 causes, man is too often accessary to his own miseries as arising 
 from this great source of disease, through his ignorance ; not un- 
 frequently also, through his carelessness, his fatalism, his cupidity, 
 his malgovernment, his vices, or, what is more excusable, his po- 
 verty. Planting wood or cutting it down, clearing lands or suf- 
 fering them to lie waste, turning the courses of rivers or neglect- 
 ing them, embanking or neglecting to embank, digging canals and r 
 ponds for use or ornament, in these and many other things, na- i 
 tions and people have often been their own greatest enemies ; i 
 not seldom from ignorance or inattention : while from introduc- 
 ing particular kinds of cultivation, from the improper choice of 
 places for towns, or houses, or military defences, and in far more, 
 we may find instances of the consequences of all the leading cau- 
 ses of the evils in question. On many of these points it is the 
 business of governments and of education to enlighten where they 
 cannot direct or interfere : where military operations are con- 
 cerned, the state has but to order and be obeyed ; taking care 
 that its agents are enlightened, wherever it must trust. If it has 
 not always watched as it ought, it is only by hearing of its errors 
 that it will learn to do what it has neglected. 
 
 In addition to what I have here said respecting the injudicious 
 choice of seats for towns or colonies, by all governments, and of 
 much more which it would be long to detail, and in addition 
 also to the careless or injudicious mode in which naval services i 
 are often performed on the shores of tropical and insalubrious cli- 
 mates, I cannot, before attending to what is merely military, avoid . 
 a remark on the mode in which it has so frequently been attempt- 
 ed to penetrate Africa. The dangers of the interior investigation, 
 arising from the tropical fevers, are sufficiently great already ; 
 while, to these, have been added, in almost every instance, the 
 sometimes greater, and generally unnecessary ones incurred from » 
 entering the country by the avenues of the great rivers, which! 
 are, above, all, the most destructive seats of this pestilence. Thus; 
 have expeditions been defeated by the deaths of the travellers, even ■ 
 at the outset ; forming an accumulation of evil, of which the facts 
 are familiar. I know not why this plan has not been abandon- 
 ed ;^ when in addition to what ought to be obvious to any one ac- 
 quainted with Africa, the comparative success of the attempts by 
 way of the desert, has demonstrated the superior advantages and 
 
MALARIA. 105 
 
 security of this route. I need scarcely point out, in addition, the 
 very obvious oversight or obstinacy of attempting effectually to 
 explore this most pestiferous country by means of unseasoned or 
 unhabituated Europeans ; while it is not very easy to discover 
 why this could not be done by the aid of negroes or natives edu- 
 cated for that purpose ; when so many individuals of these races 
 have given ample proofs of their capacities, as well as of the pos- 
 sibility of attaching them permanently to European interests. 
 
 But, as to public matters, it is chiefly in military service that 
 the ravages made by the diseases of Malaria have been frequent, 
 serious, and often ruinous ; while if those have sometimes been 
 inevitable, they have much too often been the results of neglect, 
 or of what should be called ignorance, were it not that there is in 
 reality no ignorance on this subject in the age, whatever there 
 may be in the individuals directing or executing. Lancisi, Sen- 
 nert, Orlandi, Platner, De Baumes, Zimmermann, Pringle, Lind, 
 Blane, Jackson, hundreds more, writers without number and 
 writings without measure, have explained this subject, if not al- 
 ways very philosophicallv, yet at least as to the useful or neces- 
 sary details, sufficiently ; leaving no excuse, since those who can 
 do no more, may at least read and follow. Nor is even experi- 
 ence wanting, and in abundance, nor living examples of know- 
 ledge and caution on these points : and still it w T ould seem, as 
 if fated, that the wisdom and experience of one generation should 
 be forgotten by the next, that peace should extirpate the know- 
 ledge that had been acquired in war, and that what is possessed 
 by enlightened individuals should never spread so as to illuminate 
 the public mind. 
 
 How far the great practical errors committed on this point have 
 been the consequence of oversight in the education of those who, 
 in any country, direct and command, and how far they have flow- 
 ed from a deficient and faulty medical education, wheresoever 
 established, are questions which it would not be very proper, nor 
 very agreeable* to discuss in this place ; but be the causes what 
 they may, the weighty and serious importance of all that is con- 
 nected with such neglect, cannot be too often nor too strongly 
 urged. To despise, habitually, dangers to which we are not our- 
 selves exposed, is natural, as it is easy ; but it is too late to change 
 the smile of superciliousness to repentance, when the destruction 
 of armies, or perhaps the loss of battles or of campaigns, has 
 been the result. Were the mortalities caused in armies by dis- 
 ease, the consequence of this neglect or ignorance, to be placed 
 in comparative array with those produced by the pure casualties 
 of warfare, the account would present an aspect, perhaps little 
 suspected, even by statesmen : whether or not it would produce 
 
106 PROPAGATION OF 
 
 those effects as to the future which it has seldom yet done in the 
 past 
 
 Examples might be accumulated without end, and the history 
 would be a fearful one. It is said that 10,000 men were lost by 
 Walcheren : how far the compaign itself was lost through the 
 same cause, it is not needful to ask. It is now a less painful as 
 well as a less offensive case, to tell, that when the French army 
 attempted Naples in 1528, they were reduced within a few days, 
 from 28,000 to 4000 men, by choosing an injudicious encamp- 
 ment at Baias. Similar, and from a similar cause, was the great 
 mortality in Hungary in 1566. There were excuses in 1528 and 
 1566, which did not exist afterwards, and least of all in the last 
 war ; yet all European wars, ever since, can furnish examples in 
 abundance of the same nature, from the ignorant or careless 
 choice of encampments, as from other modes of ignorance and 
 neglect, even to the selection of pestiferous situations for perma- 
 nent barracks. It was a fortunate discovery in fortification that 
 a dry ditch was more defensble than a wet one; since the safety 
 and efficiency of a garrison seem never to have entered the minds, 
 even of the Vaubans, the Coehoorns, and the Cormontaignes ; 
 though far more intimate, it must be supposed, with Malaria than c 
 ourselves. 
 
 It is much to be wished, that, not only on the subject of war, 
 but in every case of ordinary life, it could once be impressed on 
 the minds of the people, and of their governments, of all those 
 whom it may in any way concern, that the diseases of this nature, 
 that the mortality of war by sickness, are really not a necessary 
 part of the order of things ; not unavoidable mischances to be 
 placed in the calculation of events, not the irrepressible course 
 of nature; but that they are the produce of our own ignorance, 
 our own neglect, or our own prejudices. That which is esteem- 
 ed unavoidable, is suffered without remonstrance, almost without 
 regret : it is Fate, it is held irremediable, and it is not remedied. 
 It is perhaps calculated that 10,000 men can effect the service 
 desired ; but it is calculated also that the half must die of sick- ' 
 ness : 20,000 are appointed. Thus is endured what is expected ; ' 
 but let it once be believed that it is not fated, not unavoidable, 
 and means will be taken to avoid it. Man does not want exertion, 
 and as little does he want talents, would he but employ and cul- 
 tivate them; but, indolent in both, he sits down and consoles 1 
 himself with believing that thus it was destined. 
 
 And if, from want of knowledge, so has similarly destructive 
 conduct been adopted in spite of it; in opposition to information 
 and caution, and even to experience and demonstration. If the 
 supercilious contempt with which Malaria is often viewed, has 
 often been dearly paid for, even by individuals, still more bitterly 
 
MALARIA. 107 
 
 have the " Achivi" suffered from that of their rulers. It was not 
 the case of our army indeed ; but when nearly a whole regiment 
 was not only incapacitated at Malta in one night, and with the 
 loss also of great numbers, but rendered nearly useless through 
 the whole war, by persisting in occupying a village which the 
 natives had abandoned, and against the most pressing remonstran- 
 ces, it was a case which that army could have spared. And 
 similarly, three or four times, and by means of as many succesive 
 parties, was it determined to occupy as a Telegraph a rocky point 
 in Sicily between Rasaculmo and Spadafora, though thirty men 
 were successively destroyed by that Malaria against which the na- 
 tives had warned the commanding officer. And thus was a similar 
 obstinacy on the part of the French, during one of their early 
 occupations of Corsica, punished by the successive and not less 
 rapid extermination of every garrison, for a long period, by which 
 they attempted to hold San Fiorenzo. 
 
 Thus also was our hospital at Port Mahon fixed on the precise 
 spot where it received the whole Malaria of that pernicious val- 
 ley, pestiferous during four months of the year ; while by choos- 
 ing the elevation of Cape Mola, at its north-eastern margin, these 
 bad effects would have been entirely avoided. And the truth 
 must be told ; that, whether in this case or any others, the me- 
 dical staff was not sufficiently consulted or empowered, and there- 
 fore blameless, this was not the fact every where nor always; 
 since, at the commencement at least of those services, it evinced 
 the same contempt of Malaria, (a contempt which in reality was 
 ignorance,) as the military itself did, and as was displayed by all 
 our early travellers in Italy. Nor could a stronger proof of that be 
 given, than from the whole history of Walcheren ; in the details 
 as in the original arrangements and project; since little selection 
 was made even as to the sites of the hospitals, which were, on the 
 contrary, often chosen in the very worst places of this pestiferous 
 island. And lest exclusive blame should here appear to be thrown 
 .on ourselves, it was in consequence of Orloff's choice of canton- 
 ments at Naussa, in Paros, itself one of the most pestilential spots 
 of all Greece, that this army was nearly destroyed, and the objects 
 of that campaign frustrated. 
 
 And when T make use of the word contempt, 1 state a fact per- 
 fectly known to our naval and military officers, at least at the 
 commencement of our wars in the Mediterranean, and indeed 
 long after : a contempt and an incredulity respecting Malaria, to 
 which thousands of lives were sacrificed. And if there are hun- 
 dreds who have lived to believe in what they once despised, pur- 
 chasing their conviction however at a severe price, many have 
 paid the forfeit of their ignorance and pride with their lives. Nor 
 have 1 stated what, even respecting our travellers in Italy, is not 
 
108 PROPAGATION OF 
 
 known to every Italian ; to the very people as to persons of edu- 
 cation ; cautioning in vain, those, upon whom, truly English in all 
 their opinions, caution and advice were thrown away. They too 
 have at length begun to concede and to learn : but for those who 
 are now less confident in their own omniscience, their predeces- 
 sors have paid the dear ransom of their lives, and not in small 
 numbers. It has been well said at Rome, that none but dogs and 
 Englishmen walk in the heat of the day ; and it might have been, 
 added, that no one but an Englishman sneers at Malaria, though, 
 as on other occasions, often suffering deeply under his imagined 
 superiority. It is scarcely credible that all this should have been, 
 and, doubtless, that it will all be again ; that human life has been 
 thus sacrificed, by thousands, almost by millions ; and where 
 knowledge did exist and was attainable. But perhaps it is fated 
 that man's obstinacy should effect that which nature might not so 
 easily attain through any other road ; while the very slender spe- 
 cimens which I have given, scarcely implying a life in ten thou- 
 sand, may enable a reader to conjecture what, on this point alone, 
 must have been the history of war, even of modern war. 
 
 But I must not make this a book of anecdotes ; while I wish, 
 if possible, to impress on the minds of all those whom it may es- 
 pecially concern, the necessity of studies which they cannot omit 
 if they would do their duties, and of investigations and attentions 
 without which the duties of a commanding officer or a quarter- 
 master general cannot be properly executed in any climate, far 
 least in a hot one. To say that it is the duty of the medical staff, 
 may be abstractedly true ; but, in practice, or in the field, it ap- 
 pears not to have been so considered; while the accidents to 
 which I have alluded seem to prove, either that this staff is not 
 sufficiently consulted, or has not sufficient power ; since I must 
 not suppose that it is ever deficient either in knowledge or atten- 
 tion. That the fault has existed, is most certain ; and that, some- 
 where, blame must alight ; where that should fall, it is for others 
 to determine. 
 
 Be this as it may, a military commander must at least desire to 
 know the nature of the duties entrusted to those whom he com- 
 mands ; while with respect to this particular subject, though its 
 end be medical, or rather, appertaining to sanitary measures, it 
 is one which is at least as attainable, by a military man as a mere- 
 ly medical one; since it implies that knowledge of ground so in- 
 dispensible in strategy, which a very slight addition of discern- 
 ment respecting pernicious soils would render perfect as to the 
 objects in question. 
 
 If any additional inducement can be offered for these ends, I 
 wish it could be impressed on the minds of military men, as of 
 every one concerned with hot climates, that when they are terri- 
 
MALARIA. 109 
 
 fied with the very name of the plague, and are thus led to adopt 
 precautions which certainly cannot be too rigidly followed, they 
 Forget that the plague is actually as nothing in the scale of mor- 
 tality, when compared to the diseases of Malaria ; to the fevers, 
 the dysenteries, and the choleras of the tropical regions, and to all 
 those endless consequences which disable those whom they do 
 not absolutely destroy. Yet such is the weight of one name com- 
 pared to another : while the precautions against such diseases, as 
 universal and perennial as the visitations of plague are confined 
 and rare, are very widely within our power. 
 
 To detail these precautions, and to apply them to every mili- 
 tary case which may occur, would be again to traverse the ground 
 already passed. I can but refer, as before, to general principles ; 
 but I will terminate this episodical discussion with a case that il- 
 lustrates a principle as to precautions, which, in certain coun- 
 tries, it will often be essential to recollect. 
 
 In this instance an army was encamped in a very pestiferous 
 plain ; yet the health of the men did not suffer, because, being 
 near the shore, the sea breezes, predominating at that season, 
 swept back the Malaria into the interior country. From some 
 cause the encampment was transferred to another point, without 
 recollecting that the change of the regular winds was approach- 
 ing. They did commence, sweeping in a new direction across 
 the plain ; and, within a few days, many thousand men were dis- 
 abled or killed. How a better calculation respecting the periodi- 
 cal or regular winds would have saved this catastrophe, is suffi- 
 ciently obvious ; while, even after it had commenced, it appears 
 to have been forgotten that this fine army might have found shel- 
 ter from the disease, by the mere transference of the camp to a 
 spot beneath a neighbouring hill, and without surrendering the 
 military advantages of the position. If this, comparatively tri- 
 fling catastrophe, injurious to the service as it really was, might, 
 as the result of inattention or ignorance, have been avoided, it is 
 not possible to reflect, without deep regret, that it ought not to 
 have happened, and not easy to avoid some warmth in endeavour- 
 ing to show how such evils may be in future prevented. 
 
 To proceed to some cases of a different nature, the same ne- 
 glect is found on a smaller scale, in the choice of situations for 
 dwelling houses ; and if, to the term neglect I were to add obsti- 
 nacy, it would be but a truth : the obstinacy of ignorance which 
 cannot learn, or of conceit that will not. It is sufficient if 1 here 
 apply this remark to our own country ; because, although I could 
 illustrate it by abundant instances, every where, it is England that 
 chiefly concerns an English writer writing to his countrymen. 
 What I formerly remarked respecting unsuspected sources of 
 Malaria is here applicable to houses, and even to houses on the 
 
 P 
 
110 PROPAGATION OF 
 
 highest scale of opulence, in numerous places; while, if ignorance 
 baa here been a valid excuse, it ought not to be such any longer. 
 Nothing surely can be more fundamentally necessary respecting 
 the choice of a site than that it should be salubrious, or at least 
 free from absolute causes of disease, whether as a question of 
 happiness or one of economy, since it involves both. But as it 
 is unnecessary to dwell on this subject, I shall pass on to another 
 cause intimately connected with that which 1 have been discus- 
 sing, as being a modification of proximity, 
 
 The cause to which I allude may be called condensation; and 
 if it has not been well studied or described, it is one which can 
 be borne out by facts, as it might be anticipated to exist in cer- 
 tain circumstances. Or, it is easy to suppose, that while the pro- 
 duction of Malaria is gradual and constant, it must accumulate, 
 unless decomposed by chemical actions or dissipated by the 
 winds; while, from the distances to which it is frequently car- 
 ried, we have no reason to suppose that it is often or easily de- 
 composed in the common atmosphere. Thus might we antici- 
 pate that a marsh confined within the walls of a forest, as in the 
 pine swamps of America, or the marshy ground of a jungle, or 
 even our own moist woods, should accumulate Malaria in unusual 
 quantity, and therefore in unusual virulence ; and this seems to 
 be established by the most ample experience in numerous places. 
 Thus also might it be supposed that a similar soil, inclosed within 
 high hills, or occupying a valley little susceptible of ventilation, 
 should be peculiarly insalubrious ; and this is proved by experi- 
 ence, though, from deficiences in the philosophy of Malaria, the 
 cause has been often overlooked where the effect was known % 
 producing some of the usual imaginary mysteries as to this poison. 
 
 If, in the former way, we can perhaps explain the peculiar vi- 
 rulence of jungles and pine swamps, and even of woods, every- 
 where, thus also we can probably account for the activity of Ma- 
 laria in many well known parts of France, Germany, Sprain, and 
 Italy, where its diseases prevail with peculiar activity and viru- 
 lence: while the condensation, arising from want of ventilation, 
 is often the result of a screen or enclosure of trees, if sometimes 
 also dependent on the form of a valley. In the former case, the 
 remedy is pointed out ; while, fortunately, it is a practicable one, 
 because of that power over rees which is denied us in almost 
 every other case of the imprisonment of Malaria. To detail the 
 means, is unnecessary. The object is, ventilation ; and circum- 
 stances must determine how this is most easily and effectually to 
 be obtained. And, on this ground, we may see why it is, partlv, 
 that the clearing of new countries often exterminates or dimin- 
 ishes the diseases of Malaria, though there are cases, as I have aU 
 ready shown, where this is the very cause of its production. It 
 
MALARIA. Ill 
 
 is not only thai the soil is dried by exposure to the sun, that a 
 formal drainage is established, or that the cultivation of innoxious 
 plants succeeds to that of an injurious vegetation, but that the 
 poison which was formerly concentrated, is diluted or dispersed 
 by the winds. How nearly this general rule may be applied to 
 our own country residences, where uniting stagnant or still wa- 
 ters to the confinement of a woody lawn, it is quite superfluous 
 to say. Those who cannot profit by general principles, but who 
 must, at every minute, have the application made for them, are 
 not of a capacity to profit by any thing. 
 
 If our information about Acapulco is sufficiently precise, it is 
 an instance of the imprisonment of Malaria by hills ; since it pro- 
 duces all the consequent diseases, while it is the valley that can 
 scarcely be ventilated. And if I am at a loss for other remote in- 
 stances of this case, from the difficulty of discovering philosophi- 
 cal truth among the herd of travellers, St. Lucie seems to offer an 
 example of a similar nature, as do many of the vallies, somewhat 
 unsuspectedly, in the higher parts of Caucasus, by the testimony 
 of Klaproth. That Italy and Greece abound in such cases as this, 
 renders it unnecessary to specify the localities : while many of 
 the ill ventilated vallies of Switzerland produce striking examples 
 of the same nature, noted by travellers of even the most superfi- 
 cial observation. 
 
 Having said all that appears necessary on the condensation of 
 Malaria, I must proceed to inquire respecting its migration or dis- 
 persion ; an intricate, and often an apparently mysterious subject. 
 In this case, we are compelled to resort much more to facts, than 
 to theoretical reasonings respecting what ought to be, because of 
 our ignorance respecting the motions of the atmosphere and the 
 laws by which they are governed. It is true indeed, that, in a 
 popular sense, we know whether the wind blows from the east 
 or the west ; but, regulating ourselves by horizontal vanes, and by 
 the movements of vessels on a similar plane, we have formed the 
 inveterate habit of concluding that every wind must be horizon- 
 tal, and that it must move in a straight line. Facts which it 
 would be out of place to enumerate here, prove, not only that all 
 this is fanciful or hypothetical, but that while the currents of the 
 atmosphere are irregular and intricate in the greatest degree, they, 
 further, scarcely in any instance obey the common law of rarefac- 
 tion or unequal density by which they are supposed to be pro- 
 duced and regulated. 
 
 If we cannot therefore explain how a current of Malaria may 
 be directed or limited, no motion can occur in one, so unexpect- 
 ed or unreasonable, as not to find its solution in the capricious 
 and intricate currents of the atmosphere. If currents move ver- 
 tically upwards, so may Malaria ; if in the reverse vertical, the 
 
112 PROPAGATION OF 
 
 Malaria may descend ; while both these are facts ascertained. If 
 its course is curvilinear, there are curvilinear winds enough to 
 justify it; and thus of almost every caprice, in its propagation 
 from this cause, which can be imagined. 
 
 To proceed to cases or facts, since to these we must come : al- 
 though, among those to be enumerated, there are many which 
 must depend on other causes than merely intricate currents in 
 the atmosphere, whatever difficulty there may be in explaining 
 them. 
 
 The most common case requiring explanation, and which, if 
 not to be explained in this manner, must remain at present with- 
 out a solution, is that where a spot of marshy ground produces dis- 
 ease at some distance, even more remarkably than near at hand, 
 or than in its very inhabitants, or where, as sometimes happens, 
 these escape altogether. It is a case of some importance, as ex- 
 tending the degree and range of insecurity and consequently, as 
 calling for precautions that might not have been suspected to be 
 necessary. 
 
 Numerous instances of this nature have been pointed out by 
 different writers, but a few will serve to establish the fact : while, 
 however desirable it might be to notice all those which have been 
 ascertained, at least in our own country, since this is one of the in- 
 sidious cases as little suspected as it is generally disbelieved, such 
 an enumeration implies a length of detail which must be left to a 
 geography of the Malaria of England. 
 
 In Italy, it has been ascertained that the poisonous exhalations 
 of the Lake Agnano reach as far as the convent of Camaldoli, si- 
 tuated on a high hill at the distance of three miles ; this instance 
 further proving that, thus far at least, Malaria can be conveyed 
 by the winds. In France, at Neuville les Dames, above Chatillon 
 on the Indre, and at St. Paul near Villars, both situated on high 
 grounds, there are found as many or more fevers than in the 
 marshes beneath where the Malaria is produced, and the same is 
 generally true all through Bresse in the Lyonnais. Thus also the 
 plain of Trappes near Versailles is affected by the marshes of St. 
 Cyr, though considerably elevated above them. 
 
 I am also informed that a case of this nature occurs in Malta, 
 of a very marked nature ; the Malaria which is produced on the 
 beach beneath a cliff, producing no effect on the spot itself, while 
 it affects, even to occasional abandonment, the village situated 
 above. Many more similar instances might be collected ; but I 
 must be content with adding a few from our own country coming 
 under my own observation, and sufficiently well known to be. 
 easily verified. 
 
 At Weymouth, where the back-water, as it is called, produces 
 intermittents, and also autumnal fevers, commonly mistaken for 
 
MALARIA. 113 
 
 typhus, these diseases scarcely affect the immediate inhabitants 
 of its vicinity, but are found to range along the high grounds 
 above ; and the same, in Cornwall, is true of the vicinity of St. 
 Austle, receiving its Malaria from the marshes of St. Blaisey. If 
 I am not misinformed, it is equally true of the Marsh of Marazion 
 in the same county. 
 
 The marshes about Erith in Kent, also, are less injurious to the 
 inhabitants of the lower grounds near them than might be expect- 
 ed ; while their effect on the houses which are situated high on 
 the hill above, is such as, at different times, to have been very 
 severely felt by the inhabitants. The same is true of Northfleet, 
 if my information is correct ; or, the fact as stated is, that at some 
 distance, on the high ridge so well known, agues are more pre- 
 valent than below and near the point of the production of the 
 Malaria. If this is not to be explained by the flow of a current, 
 so directed as to escape the low grounds beneath these cliffs and 
 declivities, while it ranges across the hills in contact, I have no 
 solution to offer. I suspect that a similar caprice occurs between 
 the low grounds about the river Lee and the higher lands that 
 bound its valley ; but am not sufficiently certain of the purity of 
 the facts to do more than point it out as a subject for inquiry ; as I 
 must also leave to others to apply this rule, such as it here ap- 
 pears, to whatever difficulties of a similar nature they may chance 
 to discover. 
 
 But I will add one statement, extracted from Captain Smyth's 
 valuable statistical table of Sicily, because it appears to genera- 
 lize the whole of these facts ; leading to the conclusion, that, 
 nearly in an equal number of cases, the higher grounds suffer as 
 much as the lower ; the locally healthy as those which are tho 
 very seats of the Malaria. In this document, out of seventy-six 
 unhealthy towns and villages enumerated, there are thirty-five 
 situated on hills or declivities ; while, from his personal informa- 
 tion, I may add that many of them are at considerable distances 
 from the tracts which produce the disease. And I may add one 
 remark as to the theory of this propagation, derived from a writer 
 on the climate of Italy. It is, that the southern winds in that 
 country, propagate along the hills, upwards, that Malaria which 
 the northern or mountain ones do not ; such winds, independent- 
 ly of their superior power in producing the pernicious exhala- 
 tions, tending, from their temperature, to ascend the acclivities, 
 while the colder winds, as is easily understood, have the opposite 
 inclination. 
 
 I have nothing more to add admitting of any similar simplicity 
 of explanation ; but we can now see how we may attempt to ac- 
 count for the particular transference of Malaria in certain direc- 
 tions, by attending to the actual direction or the probable currents 
 
] 11 PROPAGATION OP 
 
 of the winds that pass their generating spots. And while we thus 
 explain many apparent anomalies, so we can discover remedies 
 lor some particular cases, and further, account for certain vacilla- 
 tions in the apparent production, though actually in the effect of 
 Malaria, from changes not depending on season or on the other 
 causes already or hereafter to be enumerated. 
 
 If I just noticed the case of Acapulco, as a probable one of the 
 condensation of Malaria, while, doubtless, many decided ones 
 could be found in Italy, though I have not been fortunate enough 
 to discover such in the authors whom I have consulted, it is not 
 difficult to find examples of the effect of vallies in conducting and 
 directing the Malaria. And whatever difficulty there may be in 
 explaining the exact cause by which it is conducted to a spot dis- 
 tant from its origin, and in some determinate direction, in cases 
 such as that of Northfleet, where it must ascend through an un- 
 confined air to traverse the summits of open ridges or hills, there 
 is no difficulty in comprehending how it may be conveyed to a 
 distance through prolonged vallies ; since, in such cases, it does 
 but follow the course of the narrow stream of wind in which it 
 exists. Thus it would be easy to conceive, before experience, 
 that if the plains about Fort William in Scotland could produce a 
 Malaria, that this valley was situated in Senegal for example, a 
 southerly or westerly wind might, and probably would, carry it 
 on to Inverness, or, reversing the marsh, in the reverse direction ; 
 and from experience this is ascertained to occur in similar situa- 
 tions in many places. Of these, one example may suffice, and it 
 is from Ceylon. If that valley has a name, it has escaped me, 
 though the fact has not ; and this is, that whenever the sea wind 
 blows in such a direction as to cross the swamps on the shore and 
 enter the valley, it conducts it many miles inland, so as to pro- 
 duce the fever where at all other times it is unknown ; and with 
 such decision and promptitude as to have attracted, long since, 
 the attention even of the natives, not likely to be extremely obser- 
 vant on such subjects. 
 
 But in Italy, analogous remarks, if under different modifications, 
 are almost universal. Among other things, it is a leading obser- 
 vation that, on the southern shores, the wider the mouth of the 
 valley opens to the sea, or to the influence of the south winds, 
 and the less deeply it penetrates the country among the mountains, 
 it is the more unhealthy ; as, under this form, it cannot receive 
 those northern or tramontane winds by which it would be swept, 
 while, reversely, the southern breeze is checked and accumulated 
 in its progress inwards, condensing or retaining the pernicious 
 vapours which its heat also tends to generate more especially. In 
 Sicily, and also in Greece, it is no Tess observed, and very uni- 
 versally, that vallies not only confine but conduct the Malaria ; 
 
MALARIA. 115 
 
 this being a very conspicuous fact in the latter country, in many 
 narrow vallies which open to the sea and thus conduct the breeze 
 inland, through pernicious tracts, to places not essentially un- 
 healthy. Similar modifications of ground productive of the same 
 results, are also pointed out in Italy, as elsewhere ; but I need 
 not prolong remarks, of which the chief value is, that, in the latter 
 cases at least, they indicate the obvious remedy, often of very 
 easy application : that being to plant screens of trees across such 
 vallies, so as to intercept the current ; while I need scarcely re- 
 ; peat that a similar remedy, applicable to the first cases, is pre- 
 cisely that which the Romans seem to have employed in ancient 
 times on the shores of Latium. 
 
 The case of trees presents one of much more intricacy, and 
 jalso of far greater importance. It involves, as has already been 
 j indicated, the production, or otherwise, of Malaria, as well as its 
 condensation and its propagation in various ways ; while it is also 
 ;one of the most important cases as far as soils or localities are 
 concerned, since, whether for good or evil, it is that which is 
 the most frequently, sometimes indeed almost completely in our 
 power. 
 
 For example, since the creation of an obstacle to the winds, as 
 in the planting or natural growth of woods, may either increase 
 the effects of a Malaria by confining it, or remove or diminish 
 them by cutting off a communication or diverting a former course, 
 so may the destruction of the obstacle which a forest interposes 
 to a particular current of air, introduce a Malaria to some parti- 
 cular spot where it was before unknown ; as different and oppo- 
 site changes of this nature may produce those revolutions, for in- 
 crease or abatement, production or disappearance, of disease, 
 which have so often been represented as of a mysterious nature ; 
 such ignorance also having occasionally been made rather a mat- 
 ter of boast than shame, as if it was the ignorance of all respect- 
 ing a difficult subject, instead of an unpardonable want of dis- 
 cernment on the part of the individual. 
 
 Not to recur to what relates to the actual production of Mala- 
 ria from the cutting down of forests and the breaking up or expo- 
 sure of such land, nor to the reverse case, where the planting of 
 a wood becomes a remedy, by its absorbing the moisture of a soil 
 or by screening it from the sun, nor to repeat what has been said 
 on the condensation or confinement of this poison by trees or for- 
 ests, the district of Bresse in the Lyonnais, among many more in 
 France and some few in Italy, offers, at present, examples, not 
 only of such condensation and its effects, but of both the opposing 
 effects as these relate to propagation ; namely, of their power in 
 preventing its access, as screens, and in checking its progress so 
 as to accumulate it in a place which it would otherwise have 
 
1 I 6 PROPAGATION OF 
 
 passed over; and further, of directing it in lines which it would 
 not else have followed, and to points which it would not have in- 
 vaded. To limit myself to a few well known cases from Italy ; 
 a convent at St. Stephano became unhealthy in consequence of 
 cutting down some trees ; and the extirpation of a wood brought 
 on severe fevers at Velletri during a space of three years, as also 
 happened at Campo Salino in the Pontine marshes. 
 
 It would not be difficult to quote instances in support of this 
 general proposition and these several effects, from the histories of 
 our colonization also, and from those of our permanent campaigns; 
 but while it would also be abundantly easy for me to render al- 
 most the whole of this portion of the work an amusing and some- 
 what interesting collection of facts, rather than an abstraction 
 from these for the purpose of establishing certain general princi- 
 ples, two evil consequences would follow ; that of injuriously in- 
 creasing the bulk of such an essay as is designed to be popular, 
 should that prove its good fortune, and that of diverting the atten- 
 tion of superficial or ignorant readers from what is important to 
 what is entertaining. Philosophical minds may indeed keep their 
 eye on the beacon which guides them through such a wilderness ; 
 but it is always the fate of others, in such cases, to lose sight of 
 the true path while they pursue the flowers and butterflies which, 
 are thrown in their way. 
 
 And, not to accumulate examples with which pages might be 
 rilled on the whole of this interesting part of the question under 
 review, it ought now to be superfluous, and would assuredly be 
 tedious, to point out the nature of the remedial processes in any 
 cases of this kind where the fault may be suspected to arise from 
 trees, under any mode, or to be capable of extirpation by the ma- 
 nagement of forests. It is evident that nothing but an accurate 
 study of the localities, and also of the previous history of such 
 tracts, can point out the necessary steps as to any one place ; and 
 that this is a case requiring intimate knowledge of the subject in 
 general, together with that eye for ground and general philosophi- 
 cal discernment which belongs to the practised and philosophical 
 engineer. The general principles are, now, not difficult of ap- 
 prehension ; but their application must be trusted to those who 
 are capable of applying them to particulars. 
 
 But it will not be useless, while it may be interesting, to quote 
 one noted instance, in which it appears that the removal of trees 
 has actually produced very injurious consequences : and where 
 the case is that of Rome, the space which it may occupy will be 
 pardoned. I say, appears, because I find by experience that it is 
 almost impossible to rely implicitly on any testimony, since an as- 
 sertion on one side is not uncommonly counteracted by some 
 contradiction on another. Under this reservation, I shall imme- 
 
MALARIA. 117 
 
 diately show, what indeed is far too well-known a fact, that the 
 influence of Malaria through Rome has been gradually augment- 
 < ing, and that it may be traced in a gradual progress from a parti- 
 ' cular point, or perhaps now, from more. 
 
 Not to commence from what I have had occasion to mention 
 ! elsewhere respecting the plantations or groves which, in the 
 j times of antiquity, were dispersed through the Roman territory, 
 most evidently the result of design on this very subject, and 
 j which, very particularly, appear to have been one great cause 
 I of the superior salubrity of the Pontine marshes, Lancisi remarks 
 (that in later times, there was extirpated near Rome, a forest to 
 I the southward, reaching from the heights of Frascati and Albano 
 j to the Tiber, and protecting it from the Malaria so abundantly 
 i generated in that quarter by these marshes. Thus, says he, was 
 J destruction first let in upon the Campagna : but it is since that 
 date that a similar proceeding seems to have opened Rome itself 
 ; in another quarter to the Malaria of this immediate tract of per- 
 nicious land. 
 
 If my information at least is correct, there was formerly, at 
 this point, or in a situation interposed between the Campagna and 
 the Porta del Popolo, a wood, cutting off the communication 
 through the north-east winds ; and it is since the destruction of 
 this, that the new progress of this pest, so remarkable, has been 
 noticed. If this fact should be established, or has been truly re- 
 presented, it may prove a valuable one ; as the Papal govern- 
 ment will thus acquire a remedy, as far as this point at least is 
 concerned, which it has long vainly sought in drainage, and in 
 other probable, but ineffectual improvements ; though it is diffi- 
 cult to comprehend, if this be true, why it has not been put in 
 force long ago. 
 
 But a writer can do no more than seek for the best evidence 
 in his reach, and balance it by other testimonies ; and therefore I 
 I may proceed to say, that as far as I can trust to information on a 
 subject which I have had no opportunity of examining, this pro- 
 gress of the Malaria through Rome appears to be determinate, if 
 slow ; spreading as it were, from a fixed point, and making, in 
 every year, a further step, so as gradually to drive the inhabitants 
 before it, as far at least as these are opulent, and able to quit their 
 unhealthy habitations ; since not only does poverty check the mi- 
 gration of the lower classes, but, from the causes hereafter to be 
 :l stated, their crowded streets are far less affected by this poison 
 than the dwellings of the rich. 
 
 According to these reports, it appears to enter at the Porta del 
 Popolo, or from the north-eastward ; while it may be suspected 
 here, that as far as this occurrence is new, as it is asserted to be, 
 the immediate cause must be sought in the extirpation of the mass 
 
 Q 
 
118 PROPAGATION OF 
 
 of wood just mentioned, which formerly sheltered this quarter of 
 the city from that wind which crossed the pestiferous plain. 
 
 From this point it is- said now to reach a certain distance along 
 the Corso, the banks of the Tiber, and the west side of the Pin- 
 cian hill ; continuing its course along the base of that elevation, 
 bv the church of the Trinita del Monte, and thus round the foot 
 of the Quirinal and ViminaJ hills, to the church of Santa Maria 
 maggiore. In its further progress it reaches the church of San 
 Pietro in Vincoli, diverging towards the Campo Vaccino, and 
 proceeding onwards to the eastward of the Colosseum. It is also 
 further said to have begun to enter, but at a later date, by the 
 quarter of the Porta maggiore and that of San Giovanni ; occupy- 
 ing at present, to a severe degree, the district of St. John Lat- 
 teran, and holding its course over the Coelian hill towards the 
 church of St. Gregory, where it spreads to the eastward of the 
 Palatine, towards the ancient seat of the great Velabrum and the 
 river. 
 
 To omit minuter and further details, 1 may also add, that by 
 reports more recent than those from which the preceding sketch 
 was drawn, its progress is by no means finished ; and that every 
 year adds something to the extent of its course and influence, and 
 not a little to the alarm of the inhabitants ; since, should it pro- 
 ceed for many more years in the same accelerating ratio, Rome, 
 the eternal city, may perhaps at length be abandoned, and the 
 modern Babylon as it has been named, become, like Babylon the 
 great, a desert of ruins. 
 
 In what respect this state of things may depend on an increased 
 production of Malaria in the surrounding Campagna, or whether, 
 under other winds, any portion of this evil arises from an increas- 
 ed insalubrity of the Pontine marshes or the southern lands in ge- 
 neral, I can discover no facts from travellers or in writers to en- 
 able me to form a judgment ; nor, at present, any other local 
 cause but that just named, and which relates to a greater facility 
 as to the progress, not the production, of this destructive atmos- 
 phere. But as far as regards that slowness of pace by which it 
 creeps along the streets of Rome, while it is probable that the, 
 direction is governed by that to which the currents of the winds: 
 are determined, it is equally probable that the gradual gain which 
 it makes on one point after another, is further regulated, and, in) 
 reality, caused, by the diminution of the population, and by the. 
 very fact that the people retire before it. I shall soon show howi 
 the poison of Malaria is destroyed by the circumstances which 
 attend a crowded street ; and while in this diminishing city, house 
 after house is abandoned, it is plain that new means are afforded 
 to it for another step and a further progress ; the general fact be- 
 ing further confirmed by its following those lines and attacking 
 
MALARIA. 119 
 
 those places, especially, which are most denuded of inhabitants. 
 
 Hence it is a misplaced surprise which wonders why the Villa 
 
 U Borghese, or other elevated situations exposed to a free air, 
 
 1 should be almost uninhabitable ; since it is this very freedom of 
 
 ! the air which is the source of all the evil. 
 
 One conclusion of much importance follows from this view, if 
 it be the true explanation which I conceive it to be : and it relates 
 to futurity as that may be connected with the political prosperity 
 of Rome. If it is true that ancient Rome suffered less from Ma- 
 llaria than the modern city has generally done and than the pre- 
 sent one does, and if the surrounding lands were not less poison- 
 ous then, than they are at present, or indeed under any view of 
 their comparative condition, the very fact of a more dense popu- 
 lation in former times may explain the difference, as I have here 
 suggested, and shall more fully demonstrate shortly. Thus, all 
 external causes being the same, or even should they now be dif- 
 ferent, the increasing effect of this pestilence must still go on to 
 increase, in an accelerating ratio with the commercial or politi- 
 cal feebleness of the state, and its consequent diminution of in- 
 dustry and population : and very especially, as to the upper 
 classes, with that increase of poverty which has led them to aban- 
 don their expensive palaces, and thus, from a still wider influence 
 'of depopulation around those, which I need not explain, to give 
 freer admission to that plague, which, once established, can ne- 
 ver be encountered or braved again. And if it be true, as is said, 
 that the Malaria has now reached the Vatican, it is easy to see 
 that the alarm which may desert it in consequence, will soon 
 J render a lasting desertion inevitable. 
 
 • Thus will that process of degradation which attends all states 
 •placed in the circumstances in which Rome now stands, operate 
 ■jwith increased and accelerated energy, by the aid of this ally, 
 I disease ; and should the progress of this not be suspended, should 
 | it proceed as it has lately done, depopulation itself will proceed 
 Jin a ratio which mathematicians would almost call geometrical, 
 Ijand hasten with rapid steps, a catastrophe in which the whole ci- 
 9 vilized world will partake with that city which is almost the com- 
 ?imon property of learning, art, and science, wherever existing. 
 
 As I can preserve little order in what follows, I may now point 
 fj oat some facts of a singular kind, which, if they belong to the pro- 
 pi pagation of Malaria, are also, in some cases, connected perhaps 
 Jwith restraint and condensation, and further possibly with diver- 
 sion ; while the last must be referred to that obscure circumstance, 
 the attachment of this substance to solids, which was formerly 
 mentioned. 
 
 In Rome, it is pointed out, in more places than one, that the 
 Malaria, which must there be transported, not generated, will oc- 
 
120 PROPAGATION OF 
 
 cupy, even with some permanence, and in some instances also, 
 perennially, one side of a garden or a street, while the opposite 
 one remains exempt. If, in some cases, this is connected with 
 that singular propagation just described, it is an explanation that 
 will not solve every case of the difficulty. They who know 
 Rome, and its tales on that subject, will remember the opposed 
 churches where the porter or janitor on the one side, long and 
 invariably suffering from fever, was cured by the mere transfer- 
 ence of his office to the opposite side of the same street ; and 
 where, at the same time, the duty had been always as safe as it 
 was invariably dangerous or destructive on the other. This is 
 a circumstance indeed of very frequent occurrence in various 
 parts of Italy, but I will only quote one more instance from that 
 country, out of many, because it is well known to many officers 
 then serving with our army in Sicily. The village, the name of 
 which has escaped me, unless that be Faro, was situated above 
 the Faro of Messina ; and while one side of the street was in the 
 highest degree pestiferous, producing mortal fevers among the 
 troops, the opposite one was entirely exempt. 
 
 Whatever apparent mystery there may be in these occurrences, 
 and though perhaps the same explanation will not apply to every 
 case, there are some common facts in meteorology which will 
 probably help to explain some of the instances in question. It is 
 probable, as I have shewn in another place, that the matter of 
 Malaria is often connected with vapour, or mist ; conducted by 
 it, and probably defined, as to its place and extent, by this, its 
 vehicle. Now, as in the case of dews, or more particularly in 
 that of hoar frosts, we often find this occupying a certain extent, 
 both superficially and as to level, reaching for example to a par- 
 ticular hedge in some valley, and then ceasing by a most definite 
 and sudden line, while also terminating at a particular altitude on : 
 the trunks or branches of trees, as if suddenly cut off, it is not 
 difficult to imagine how a Malaria thus united, might be as defin- 
 ed and as local as it is actually found to be in these singular ca- 
 ses. Of causes depending on the direction of winds, it is not also 
 difficult to imagine more than one modification: since the poison- 
 ous spot might lie in its peculiar current, or, otherwise, be a 
 place sheltering a substance which, as I shall presently shew, 
 seems occasionally to subside and rest, as if it possessed a specific s 
 gravity greater than that of the surrounding atmosphere. 
 
 A domestic instance of the same nature is perhaps even more 
 worthy of notice, from the great extent of range through which 
 this remarkable fact occurs, no less than from the accuracy with 
 which the limits of the Malaria are defined; while this case is 
 even the more remarkable, as being an example of transportation 
 and not of production. For the truth of the fact itself I have the 
 
MALARIA. 121 
 
 testimony of the country at large, as well as that of some indivi- 
 duals of accurate habits ; while whoever is inclined to doubt, 
 may find the means of investigating it without difficulty. 
 
 This is the high road between Chatham and Feversham, in- 
 j volving an extent of about twenty miles ; and it is here remarked 
 ! by the inhabitants, that in every village and town, including also 
 ; the detached houses, and comprising, from Chatham, Raynham, 
 I Newington, Sittingboume, Bapchild, and Boughton, the ague oc- 
 , curs, on the left hand side of the road, generally, and is unknown 
 il on the right side ; though the breadth of the road itself forms the 
 | only line of separation. If I were to repeat, in addition, some 
 : special facts, believed and related by the inhabitants of some of 
 ( these places, and at Sittingboume among others, this separation 
 is even more wonderfully and mysteriously precise than the ge- 
 neral fact as thus stated would prove it to be. I need only add, 
 that the lands producing this Malaria are situated generally at 
 I about a mile distant, on the left hand, being as well known as the 
 road itself. 
 
 I do not pretend to explain the almost marvellous singularity 
 of this particular instance ; while it would, in reality, be far more 
 convenient to disbelieve it, as is the not unusual practice of phi- 
 losophers in similar cases. But I cannot doubt what so many 
 agree in asserting ; while, as in not a few other difficult cases of 
 unexplained facts, it is not easy to comprehend the nature of the 
 imagination which could invent such a tale, nor the courage 
 which should persevere in asserting an untruth so easily detected. 
 And to disbelieve, merely because we cannot explain, is more 
 convenient to ignorance and vanity, than it is either philoso- 
 phical or modest ; as it is the not uncommon proof of both ; 
 while I presume I need not say, that philosophy is as little likely 
 hereafter to profit by sceptics of this nature, as it has hitherto 
 done. Modern research has proved that many things, once incre- 
 dible, are true ; since, even in science, the " vrai" is not always 
 the " vraisemblable :" but such discoveries have not been made 
 by those whose vanity rejected as false what they did not under- 
 stand : and never will. That guns which had been reposing for 
 a century at the bottom of a deep sea, were red hot when brought 
 up to the light of day, was as little believed and as much ridiculed, 
 as the limitations of the Malaria in this case will probably be by 
 the sceptics in question : yet the investigations of the same cre- 
 dulous person proved its truth, and added a new and interesting 
 fact to chemical science. 
 
 If this remarkable instance does not seem to be amenable to 
 any of the solutions which I have just suggested, if it cannot be 
 brought under any rule dependent on the direction of winds or 
 aught else, since the boundary line is so vague a limit, and so va- 
 
122 PROPAGATION OF 
 
 riable as regards any causes which we might imagine possible 
 ones, it is not so widely removed from the case of Faro, and from 
 some of those occurring in Rome, as to be an absolutely solitary 
 difficulty. Under some laws, it must be : and, as far as these 
 cases accord, those laws must be general ones, while they must 
 be either chemical, or meteorologically mechanical. We are in. 
 ignorance ; that is all : but at some future day, they will be known ; 
 though not till the entire subject has been studied on those philo- 
 sophical principles which have never yet been applied to it. 
 
 I must yet add one remark before proceeding to the next class 
 of analogous phenomena ; because it really seems to be demand- 
 ed, not in this particular case only, but with respect to the whole 
 subject very widely. Of these last facts, the partial course, limi- 
 tation, and definition of Malaria, there can be no possible doubt; 
 so numerous are the cases, every where, and so often have they 
 been not merely described, but proved by the most ample expe- 
 rience. Yet there are none which have met with more ridicule, 
 not to say opposition merely, in our own country, by those who 
 affect to treat with doubt or contempt the whole of this subject; 
 among whom, I grieve to think that there should be any in the 
 profession of physic. Claims to superiority, if this be one, are 
 better proved by knowledge than by the want of it : and opinions 
 of this nature, worthless at all times, are much misapplied where 
 human life, as well as suffering, is so deeply concerned. It will 
 be abundant time to controvert what is erroneous, when the dis- 
 orders which have been so long misunderstood shall be better dis- 
 tinguished, and when we shall have learned to prevent them by 
 removing their causes. 
 
 The caprices of Malaria with regard to level, are often among 
 those the least easily explained ; though in certain cases, the so- 
 lution is sufficiently obvious. There appeared no great difficulty, 
 as long as it seemed an invariable rule in Italy, where this ex- 
 treme partiality of transmission or existence was first remarked, 
 that the Malaria lay near the ground, and was transmitted in the 
 direction of a stratum near its level, in preference to a higher 
 one. Thus it was found safe to sleep in the second or upper 
 story of a house, while the fever seized on those who lay below ; 
 and thence certain well-known practices in that country, relating 
 to the closing and opening of windows. The fact indeed is suffi- 
 ciently common, elsewhere : and if it required confirmation, Dr. 
 Hunter will inform us, that in the Spanish town barracks in Ja- 
 maica, where the barrack consisted of two floors, three cases of 
 fever occurred in the lower story for one in the upper. 
 
 The solution here seems easy, and perhaps it is also the true 
 one. It is, that the Malaria is especially united with that trans- 
 ferable substance which forms the foggy stratum; or that the 
 
 
MALARIA. 123 
 
 lowest portion of the atmosphere in the act of depositing water, 
 is its vehicle and its residence. And this solution, while it agrees 
 with the popular opinion respecting low mists, as it does with a 
 2;reat variety of facts relating to the conduct of Malaria, noted on 
 various occasions throughout this essay, is apparently connected 
 also with one particular fact which will soon come under re- 
 view. The only apparent difficulty lies in an analogous, but 
 somewhat jarring circumstance which has come under my 
 notice, by means of information which, being unconnected with 
 any theory or any knowledge of this circumstance, or of the sub- 
 ject in general, being in fact a mere popular observation from 
 experience, can scarcely fail to be correct. This is, that on the 
 coast of Norfolk, in some places where Malaria prevails, it selects 
 preferably the second or upper story, while the lower one as in- 
 variably escapes. Both facts may however be equally explicable 
 on the general principles already examined ; as, in the last case, 
 the direction may be that of a local current of air, determined by 
 circumstances which would probably be discovered on inspection. 
 In any view, these different facts are worth detailing, on account 
 of their practical utility; as leading to precautions which might 
 otherwise be overlooked. 
 
 Whether the specific gravity of the poisonous gas itself which 
 constitutes Malaria, or that of the air which, as a peculiar modi- 
 fication of the atmosphere, forms its most convenient vehicle or 
 repository, is connected with these phenomena, is a question yet 
 to be investigated. But there are other facts which seem to prove 
 that it can be lodged and retained, even where it has not been 
 produced ; though whether from possessing a greater weight than 
 that of the surrounding atmosphere, or because sheltered from 
 that movement of circulation which is unceasing, in all open 
 places, even where there is no sensible wind, is the point to be 
 examined. To name a striking case of this nature, I may refer 
 to Valetta, alluded to on a former occasion, on account of the 
 consequences which almost invariably occurred in the Floriana 
 guard, while other parts were little affected, or retained their 
 health. Here, the ditch was very deep and narrow, but so per- 
 fectly dry that it could not be suspected of producing the Malaria 
 to which the effects in question were owing. Nor could this be 
 explained, except by supposing that it lodged and protected from 
 dissipation, a current of noxious air, produced from that salt marsh 
 which seems to be the source of Malaria in Valetta, and which 
 the sea breeze directed on to this spot. Nor is this explanation im- 
 probable, either for this case or other similar ones, when we know 
 that carbonic acid, as well as watery vapour, or a moist atmos 
 phere, can thus remain at rest on the ground, or any other place 
 
I 2 I PROPAGATION OF 
 
 where it is protected from the general circulation of the atmos- 
 phere, for a great length of time. 
 
 That I may keep the chemical question which relates to the 
 propagation of Malaria by itself, I shall here notice the facts that 
 bear on its attachment to solid substances. 
 
 In the Campagna of Rome, it is remarked that if the labourers 
 cut down certain plants, (a bushy thistle, chiefly, of which the 
 botanical character has escaped me,) a fever, that would other- 
 wise not have occurred, is the consequence. The Malaria seems, 
 or is thought, to be entangled within it and to be let loose by this 
 disturbance. That there is any analogous fact ascertained in our 
 own country or elsewhere, I know not ; but if it be the truth f 
 which is asserted, it is probable that the cutting down of reeds : 
 in our own marshes may be the incurring of a hazard that might 
 not be encountered on merely passing through such lands. In a 
 subject on which we are yet so imperfectly informed, it is at least 
 deserving of further attention and inquiry, and therefore it is 
 worth recording. 
 
 Further, it is a common remark in many parts of Italy, that 
 as long as the labourers are in the erect posture, they incur little 
 danger, but that the fever attacks those who sit down or lie on 
 the ground, as if the poisonous matter extended to but a small 
 altitude above it. Whether, in this case, the cause be, as in the 
 former, an attachment of the Malaria to the ground itself, or to 
 its vegetation, or whether it is that it is a part of a ponderous 
 stratum of air lying on the ground, as carbonic acid does in the 
 Solfatara, is a question which requires investigation, at least as 
 far as philosophy is concerned ; but whatever be the cause, this 
 also is a fact worth recording, because it may be a general, if a 
 neglected one, and may exist, with pernicious and overlooked 
 results, in our own country. 
 
 In such cases as this, from the far inferior virulence of the poi- 
 son with us, the result might be a very slight fever, or at most an ; 
 ordinary one ; while, as such an event would most frequently oc- 
 cur during the time of harvest, it would naturally be attributed to 
 heat or fatigue, or to the influence of the sun ; and might thus, 
 under peculiar symptoms, as it most unquestionably often has, be : 
 even considered a phrenitis. These false judgments, and their 
 pernicious consequences as to the practice, are but problematical 
 examples possibly (though I cannot help thinking them often real 
 ones) of the mischief arising from ignorance as to this cause of 
 fevers, and from the assignment of imaginary ones ; and if I have, 
 in the medical portion of this work, noticed the palsies produced 
 in the same manner, the probability of this being the real cause, 
 is also confirmed by what happens in the pernicious districts of 
 Italy under the same carelessness. If, in the Maremma of Tus- 
 
MALARIA. 125 
 
 | cany and elsewhere, it is generally a dangerous fever which seizes 
 I the incautious labourer, so, very often, is it apoplexy or palsy ; 
 | while, as I have had occasion to remark in another place, imme- 
 1 diate death is often the consequence there of lying down on the 
 | ground ; the labourers being frequently discovered dead, when 
 : supposed to be asleep, by the way sides or in the fields. 
 
 Unaware of any thing further of any importance that bears on 
 these cases, [ may now inquire how far the propagation of Mala- 
 I ria, or its action on the body, which cannot here be easily sepa- 
 I rated from that, depends on chemical conditions of the atmos- 
 phere. This is a question in which we have no guides but ana- 
 logy and detached facts ; since, as long as we continue ignorant, 
 both of the nature of Malaria and of that of its union with the at- 
 mosphere, we can derive no aid from theoretical views. 
 
 If not rigidly a gaseous matter, it must be such, or nearly such, 
 in its union with the air ; and, not improbably, the conditions ne- 
 cessary for that union, must resemble those which rule bodies 
 that enter into a similar combination. If therefore, odoriferous 
 substances be allowed to present an analogy, it should be most 
 easily united with a moist atmosphere, and most easily diffusible 
 through such an one. And further, it seems tolerably well prov- 
 ed, that the matters of contagion also are most easily diffused 
 through a similar atmosphere, and that, in a dry one, they are with 
 difficulty propagated, or altogether destroyed. And as the ana- 
 logy here seems more perfect* we might conclude that a moist 
 atmosphere was really favourable to this process as it relates to 
 Malaria ; or that, in this condition of the air, the diseases which 
 it produces are most easily propagated. In how far a moist air 
 is favourable to the production of the poison, is a question diffi- 
 cult to disengage from this one in a practical view ; but as it falls 
 under the subject of season and climate, it will inevitably recur 
 j hereafter. 
 
 In this case, before noticing what may seem to confirm the the- 
 ory, I must interpose a medical remark, which, if it is a fact, may 
 affect some of the conclusions on this subject. This is, that the 
 body is rendered more susceptible of such diseases by the influ- 
 ence of a moist atmosphere. Thus does physic pronounce ; but 
 jit assuredly has not been demonstrated. It may possibly be so ; 
 jbut if it cannot be proved by something more than the readier 
 ijlappearance of the diseases of Malaria, it may be utterly unfound- 
 ed ; while the easier propagation of the poison itself, will account 
 for the phenomena, and render that solution unnecessary. That 
 
 St has been adopted as an hypothesis to explain a fact, because a 
 )etter explanation was not at hand, seems probable. 
 •| As to the facts which confirm the opinion that Malaria is pe- 
 culiarly propagated by a moist atmosphere, they are perhaps not 
 
 R 
 
126 PROPAGATION OF 
 
 very definite, but they are numerous and various ; the variety, in 
 this case, atoning in some degree for the want of a more perfect 
 demonstration from one fact. If, among numerous circumstances, 
 there is always one steady cause present, it is probable that this 
 is the cause sought for. 
 
 Now, it is not only a popular observation that Malaria is es- 
 pecially conducted by common fogs, but an observation so rooted, 
 as to have led to the very universal error among the people, of 
 supposing the fog itself to be the very poison and the cause of 
 disease. Nor is it merely a popular observation ; as a wide ex- 
 perience of a much more accurate kind, shows that it is a fact on 
 which we may repose without hesitation. If the fogs of Holland 
 are proverbial, the truth seems to be the same in our own country, 
 in America, and elsewhere ; as it appears to be equally true of 
 the intertropical climates, where the mists and fogs have a cha- 
 racter so different ; being commonly distinguished by their heat, 
 as our own are by their coldness. 
 
 And as connected with this question, it cannot be irrelevant to 
 remark, that the intermixture of Malaria seems to be the real 
 cause of the pernicious nature of fogs : allowing for some excep- 
 tions or modifications arising from the action of cold and mois- 
 ture, or heat and moisture, which medical readers will easily sup- 
 ply. If it were not so, the same diseases which the pernicious 
 fogs of fenny countries produce, should occur in elevated or moun- 
 tainous situations subject to be involved in clouds, since the cloud 
 is, in every other respect, a fog. If it were not so the fogs of dry 
 countries should produce the same diseases as those of moist 
 ones, which they do riot ; and if it were not so, the westerly fogs 
 that so often arrive in our island from the Atlantic, should gene- 
 rate the diseases of Malaria, like the easterly ones arriving from 
 Holland or formed on our own fenny coasts, which they are ne- 
 ver known to do. And to confirm this, it is remarked, that while, 
 in Flanders, (in Artois,) it is the south-westerly and southerly 
 winds which bring and spread disease, inconsequence, obviously, 
 of the lands which they traverse, as well as of their own con- 
 ducting qualities, it disappears as soon as the sea wind from the 
 northern quarters sets in, although this is accompanied by dense 
 and durable fogs. And the same rule will be found to hold good 
 in many parts of the Mediterranean, as well as in France, in nu- 
 merous cases. 
 
 The next fact in support of this view, is analogous, yet some- 
 what different ; while it is also a popular observation, and not 
 less a matter of more accurate medical evidence. In our own 
 climate, it relates to the pernicious nature of the morning and 
 evening mists formed on low grounds ; and, in the hotter climates, 
 I need scarcely say that the effect of such mists in generating fe- 
 
MALARIA. 127 
 
 ver, is as notorious as any fact the best established upon this sub- 
 ject And while, in these cases, the progress of the sun upwards 
 ! in the morning; is the remedy for the morning mists, as the day 
 I altogether is for those of the night, this fact also seems to confirm 
 ! and illustrate the same opinion, namely, that the watery or moist 
 ! atmosphere is the active conductor or repository of the Malaria, 
 'and that when the former is dissipated, the latter is checked in its 
 progress, possibly indeed in its production; entirely dispersed, 
 lor, it may even be, destroyed. This also explains the no less 
 common error respecting the cause of the poisonous effects of 
 dew in hot climates, since this is obviously also a case of the pro- 
 pagation, possibly also of the production, of Malaria. It is not 
 the dew itself which is the poison, but the fever-generating gas 
 j which is united to the watery atmosphere whence it is precipi- 
 tated. 
 
 I If this also explains the influence of night, generally, in propa- 
 gating Malaria or producing its diseases, so does that well known 
 | fact, in return, confirm the general theory in question. How 
 jtruly night, no less than morning and evening, is the time of dan- 
 jger from this cause, is too well proved by the experience of Italy 
 I to need any other proof: though everywhere, and in every way, 
 lit is among the most received and best proved of the facts belong- 
 ing to Malaria and its diseases. 
 
 Thus also is it especially remarked, that if a hot day is succeed- 
 ed by a cold and damp night, the effects of Malaria are much 
 augmented ; and the same analogy holds as to similar changes in 
 seasons, or as to incidental ones occurring in any manner. Hence 
 if cold and wet weather should unexpectedly take place in the 
 midst of a hot summer, an augmentation of severity, or a state of 
 disease before not in existence, will occur ; and hence also se- 
 vere epidemics occur particularly, if, to such a hot summer there 
 should succeed a cold and rainy autumn ; the production of the 
 poison, as I formerly remarked, being apparently augmented in 
 this manner, while the atmosphere is also rendered a better con- 
 ductor. The general philosophy applicable to all these cases, is, 
 ithat watery vapour, or a moist atmosphere, is the best solvent 
 ; jand conductor of Malaria, as a dry one is the worst ; while inde- 
 pendently of the different effects of those two states on vegetation 
 |"!and on putrefaction, it is the effect of the sun to evaporate or dis- 
 perse, possibly in a great measure to decompose, that gaseous 
 ■; matter, which is condensed, and probably very often again pre- 
 cipitated, during the evening, together with the vapours which 
 had been held in solution in the air. 
 
 It is from the same cause partly, that arise the notorious effects 
 of the rainy season in the tropical climates : the general reason- 
 ing being the same, while I need not dwell on the particulars in 
 
128 PROPAGATION OF 
 
 these most violent cases ; the more, that I have been so often 
 obliged to allude to them for different purposes. And if such 
 consequences occur even where there are no marshes, it is, ob- 
 viously, as I have remarked elsewhere, because the very soil 
 becomes virtually a marsh under such rains and amid such a ve- 
 getation. When physicians therefore, arguing as Park seems 
 thoughtlessly to have done, attribute the production of fever, or 
 of Malaria, to the rain alone, or to a moist atmosphere, attempt- 
 ing further to confirm this theory by saying, as Lind has done, 
 that even in England, a rainy season will produce remittents and 
 intermittents, and in the healthiest districts, or where Malaria is 
 unknown, it is that they have overlooked all the obscurer places 
 and causes which it has here been my endeavour to point out ; 
 thus throwing a very considerable, and also a very dangerous, 
 confusion into this plain subject. 
 
 Let me here subjoin one remark as to the effect of night, which 
 I ought not to reserve ; though I am not satisfied of its value and 
 truth, seeing that there are contradictions on this subject. It is 
 Italian experience however ; and all that I can do is to collate it 
 with other Italian experience, allowing the reader to strike the 
 balance which 1 cannot. The assertion is, that however Malaria 
 should be present in any given spot, there is no hazard after nine 
 or ten o'clock at night, or that its influence belongs to evening 
 rather than to proper night. It is conceived, of course, here, that 
 as it is entangled in the morning vapour, becoming dissipated or 
 destroyed as the sun approaches the meridian, so when the con- 
 densation of the evening mists has been completed, it is precipi- 
 tated and rendered inert or null. All that I can say is, that it is 
 quite possible both assertions should be true, in different places 
 and in different seasons ; as it is easy to conceive how the me- 
 teorological operations connected with vapour and dew, may vary 
 in their duration, or in their relative periods of commencement 
 and termination. As a question of practice, for the convenience 
 of those who may be under the necessity of exposing themselves 
 at night, the knowledge of these variations in the propagation or 
 influence of Malaria may be useful ; though they must be ascer- 
 tained for each place, by trial. 
 
 1 had thought that such general remarks, be the country Africa > 
 or Italy, might have been applied by any one to our own cases 
 and our own island ; that I might have saved myself the perpe- 
 tual trouble of applying every fact and every rule to England, 
 that what I had explained of the Malaria of other lands, or of the 
 subject in general, would have been sufficient to enable any one 
 to make the inferences desired ; or, that if an Italian fish-pond, a 
 Flemish ravelin, or a Dutch ditch, was pestilential, so might 
 ditches, fish-ponds, and fortifications be judged pernicious among 
 
MALARIA. 129 
 
 ourselves. Experience has taught me the contrary : Malaria is 
 indeed an Italian word; but 1 know not that Miasma would have 
 served the purpose better. Let me therefore illustrate, for our- 
 selves, this last set of facts. 
 
 It is said, and believed indeed, that the night air is unwhole- 
 some. True, it is so, but not necessarily or not always ; other- 
 wise at least than as mere cold may be injurious ; while the effects 
 of that, such as they are, are well understood. It is thought un- 
 wholesome because it is cold, or because it is damp : these are 
 the reasons assigned ; but the philosophy is false or confused, and 
 thus the rule of avoidance becomes an inconvenience without be- 
 ing a precaution ; while as an inconvenience, it is forever broken. 
 It is broken also when this air is not damp and not cold, because 
 the philosophy is erroneous : and hence danger and disease which 
 real knowledge would have prevented. No one fears a summer 
 evening, even a mild summer night, unless indeed he shall find or 
 fear a dew. Yet here lies the very danger ; in a land of mea- 
 dows and parks and ponds and rivers and woods, a thousand times 
 more hazardous than all the nights of all the winters that ever 
 were. This is the real night air to be feared, even though the 
 grey mist should not rise, as it is called, or the dew not fall. To 
 take a pleasant evening walk by the banks of the river or the lake, 
 to watch the trout rise from the fish-pond or the canal at the 
 evening flies, to attend the milking of the cows in the green mea- 
 dow, to saunter among wet groves till the moon rises, listening to 
 the nightingale, these, and more, of such rural amusements and 
 delights, are the true night air, the Malaria, and the fever. 
 Whence else should fevers come ? and do they not thus come in 
 Italy and in Africa ? Have they other causes in Rome or Mantua 
 than here, and shall we ever learn to believe that they have rio 
 other ? The Thames indeed is not the Congo, nor can we pa- 
 rellel Ostia or Terracina ; the fevers do not slay in three days ; 
 but the disease is the same, the poison the same, and the same is 
 the cause. 
 
 The remedies, such as they are, for these cases, consisting in 
 avoidence and certain modes of prevention, are, like the fact it- 
 self, so familiar, that it is scarcely necessary to enumerate them. 
 The basis of all is, avoidence simply, and, above all, to avoid 
 sleep under such exposure; as the effect of this state of the body 
 in rendering it unusually susceptible of those diseases, is proved 
 by universal experience. The other class of preventive reme- 
 dies comprises modes of exciting the animal powers by food, spi- 
 rituous liquors, and so on, or of diminishing its sensibility by 
 narcotics, such as tobacco and opium. Of the utility of these ex- 
 pedients, the experience is ample. Besides this, there are cir- 
 cumstances, such as may occur in camps, for example, as well as 
 
]30 PROPAGATION OF 
 
 in other cases, where the production of fire and smoke may ope- 
 rate, and appears actually to do so, in destroying the Malaria or 
 impeding its propagation. 
 
 Hence, in the first place, the general practice in countries noted 
 for Malaria, not to leave the house in the morning without food, 
 or without the previous use of spirituous liquors ; and hence also 
 the great use of tobacco in Holland, as well as its adoption by 
 military men in campaigns. To avoid falling asleep, particularly 
 in the night, is the steady recommendation of even the postillions 
 of Lombardy ; and 1 need scarcely remind any reader of travels 
 how the same doctrine is enforced respecting the dews of the in- 
 tertropical climates. 
 
 With respect to the former remedy, such at least is the opinion 
 of that country, as of many others, from experience real or ima- 
 ginary ; and such indeed has been a prevailing belief among phy- 
 sicians as well as the poeple ; as is far too well known to insist on. 
 Yet Rush, from whom it would not be prudent to differ without 
 strong reasons, and Mosely, whose opinions have not always ob- 
 tained the same respect, assert, that even the moderate use of 
 wine renders persons more susceptible of the yellow fever, or of 
 the remittents of hot climates in general : while, in the noted epi- 
 demics of New York, the former physician was accustomed to 
 urge even a great degree of abstinence from food, as a security ; 
 confirming his opinions by his own practice on himself. It is as- 
 suredly as difficult to decide between contending evidences, as it 
 sometimes is to attain the truth at all in physic. No one doubts 
 indeed that excess, whether in eating or drinking, but especially 
 in the latter, is pernicious in those situations ; but it is difficult to 
 admit that a degree of abstinence capable of producing debility 
 should not render the people more susceptible of fever, since this 
 is the admitted effect of every debilitating cause. Nevertheless, 
 it seems necessary here to suspend our judgments, as far at least 
 as the hot climates are concerned: while if the comparative ex- 
 emption of the French or Spaniards, when compared to the En- 
 glish, under these circumstances, seems rather to depend on the 
 difference between moderation and excess, though probably also 
 as I shall here presently show, arising from the superior security of 
 a vegetable diet, there may be peculiarities concerned in this case, 
 depending on climate, on which we, unacquainted with the disease 
 in these situations, are not competent to decide. 
 
 On this subject however, Sir J. Pringle is decided, and from 
 an experience the nature of which is well known to all medical 
 readers ; recommending the use of wine and of a full or good 
 diet, and thus, while he agrees, assuredly, with the great majority 
 of medical practitioners, and with, probably, all the people of 
 Europe, opposing experience to experience and judgment to judg- 
 
MALARIA. 131 
 
 ment. Such also was the opinion of General Monnet at Flushing, 
 
 and such his practice ; consisting, like that of the Dutch in gene- 
 
 ! ral, in giving some spirituous liquor to his men early in the morn- 
 
 ing: while the same opinions prevail all through France ; it being 
 
 I invariably said by the physicians of that country, that the use of 
 
 j wine is indispensible in the marshy districts. 
 
 How shall we reconcile conflicting testimonies ? unless we 
 should suppose some peculiarity in the fevers of America, or per- 
 J haps conjecture what has happened too often in physic, that the 
 j American physician has viewed this question under a prejudice 
 I or an hypothesis. It may perhaps indeed be the fact, that the 
 i remarks in question were intended to apply rather to that conta- 
 i gious, if disputed, fever, the notorious Bulam disease, than to the 
 ! yellow, marsh, or remittent fever; but even in this case we re- 
 j main still at a loss ; since it has been a general conviction that the 
 I use of a good diet and wine enabled men to resist the attacks of 
 
 all the contagious fevers. 
 I The superior security of the officers to the men in naval, or 
 I maritime, service, when employed together in duties on shore, 
 has long been remarked ; and if other causes than a better diet, 
 I well known to physicians, may be supposed here to aid in the re- 
 ! suit, I have found that those intelligent naval officers whom I have 
 questioned on this point, attribute their superior exemption solely 
 to the causes under review ; assuring me that they had on numer- 
 | ous occasions levelled themselves with the men in every circum- 
 stance of exposure, clothing, fatigue, sleeping, and so forth, and 
 that remaining in health while their entire boats' crews sometimes 
 caught the fever, they could not discover any other difference, 
 and had become convinced that the superiority of their diet and 
 the regular use of wine formed their protection. That similar 
 opinions have already prevailed through our armies, as to the 
 relative security of the officers and men under exposure to the 
 causes of fever, in all countries and climates, I surely need not 
 urge ; and after all the cross-examination to which this subject 
 can be submitted, so as to abstract and allow for other differen- 
 ces, it seems impossible to doubt that these opinions are well 
 ! founded. 
 
 To speak now of the other mode of prevention to which I have 
 ! just alluded, instances might be quoted, and from the histories of 
 j military campaigns as from other cases, of the utility of fires and 
 I smoke ; nearly the whole of these useful doctrines being embodied 
 ! in the philosophy of Uncle Toby respecting the radical heat and 
 | the radical moisture. If this has sometimes been disputed, and 
 i the action of fires in such cases not seldom also misapprehended, 
 ! it has arisen as usual, from a confusion of ideas, or a confounding of 
 j different circumstances. That in this case they may act, at least 
 
132 PROPAGATION OF 
 
 in two ways, is obvious ; that is, by drying the surrounding air 
 and thus diminishing its conducting power, and by producing a 
 dispersive ventilation, or bringing a salubrious mass of air on an 
 unhealthy point : while I need not insist on their further and me- 
 dical effect on the susceptibility of the persons exposed to the 
 poison. As to facts in proof of the utility of fires, Lancisi points 
 it out as to Rome ; and even Pliny, long ago, declares the same 
 opinion, quoting, further, the authorities of Empedocles and Hip- 
 pocrates to the same effect. That Napoleon took the same view 
 of their use, adopting this expedient very largely, and with 
 success, when his armies were occupied in the very worst dis- 
 trict of Italy, is a specimen of military experience which may 
 save the necessity of quoting others less decisive. One very point- 
 ed case, of a civil nature, is also worth recording ; because, while 
 it is always particularly easy to imitate, and has been most unfor- 
 tunately neglected, the circumstances are such as to interest our- 
 selves, as colonists under some of our least satisfactory experi- 
 ments of this nature. In this case, the superintendant engaged 
 in directing the cutting of wood in Africa, erected thirty earthen 
 furnaces on the spot where his men were employed, lighting them 
 every day. Before this, he had always from forty to forty-eight 
 of his workmen sick; when, in a short time, they were reduced 
 to twelve, then to four, and finally to one. Perhaps governors 
 in Africa may profit by the hint ; if indeed they do not already 
 know every thing belonging to this subject, interested as they are 
 in it. 
 
 It is perhaps as much out of the place here, being a medical 
 rather than a merely physical question, as it is superfluous to me- 
 dical readers, to notice those conditions of the body as to debility, 
 which render it peculiarly susceptible of the action of Malaria ; 
 while it would be utterly so to specify the debilitating circum- 
 stances, familiar as they are among medical writers. They are 
 however important facts for the people, even in the case of our 
 own country ; and were it possible that such a work as this 
 should ever reach the hands of the multitude, they would have 
 justified a distinct code of familiar rules. 
 
 But as I have been in a similar manner forced into a notice of 
 the predisposing causes of the diseases of Malaria in considering 
 the modes of prevention, I may here examine one, which, while 
 it is not much known in our own country as a fact, or at least a 
 fact established, appears of infinite importance to travellers, or 
 residents in tropical and dangerous climates ; that importance be- 
 ing also materially enhanced by the extraordinary, and indeed al- 
 most universal neglect which it experiences every where, even 
 at this day. To that neglect in particular, it would seem that 
 we must in a great measure attribute the almost universal mortal- 
 
MALARIA. 133 
 
 I ity among our travellers into the unknown parts of middle Af- 
 i rica. 
 
 It has been frequently remarked by travellers as well as phy- 
 | sieians, that what the latter call errors of diet are, in the tropi- 
 | cal climates, common causes of fever : and yet that observation 
 ;has been so vaguely stated and so little urged, while its nature 
 (has also been so little explained, that it seems scarcely to have 
 .made any impression. It may not be easy to explain why an ac- 
 jtion on the stomach so apparently simple as that of particular 
 kinds of food, or that of eating in the heat of the day, should pre- 
 dispose to the fever of Malaria : and we must be content at pre- 
 sent with the vague belief that it is a cause of temporary debility. 
 
 Not to quote proofs or statements beyond necessity, it may al- 
 most be sufficient to refer to Dr; Clarke's observations on the 
 Crimea, where he points out the fact with his usual energy ; 
 istating also the substances, such as butter, for example, which 
 Ithus, in his mode of expressing himself, produce fever. From 
 numerous other testimonies, it appears that the same hazard is 
 incurred by the large use of animal food in the same circum- 
 stances, and most of all, if eaten, as European use, in the middle 
 !of the day, or frequently in one day ; and on examining Niebuhr's 
 iaccount, it is most apparent that the deaths of his companions 
 were the consequences of gross feeding, or, literally, of gluttony. 
 It would not be difficult to analyze the histories of other intertro- 
 pical travellers, so as to draw the same conclusion as to their 
 fates ; and, among others, it is not unlikely to be the real solution 
 3f the extermination of Capt. Tuckey's party ; since the causes 
 sought for at the time did not appear very satisfactory. 
 
 On this question there can perhaps be no better evidence than 
 ;he opinions and practices of the intertropical nations themselves ; 
 imong the mass of whom this subject seems well understood ; 
 While in many countries, it is a caution actually often given to 
 Europeans by the natives, though most generally neglected by 
 fhem, and most particularly, it is said, by our own countrymen. 
 i ft is, possibly, from long experience, in some measure, of its ad- 
 vantages, as well as from more obvious causes, that a vegetable 
 piet is so general throughout the aborigines of the torrid climates; 
 While it is doubtless from principle also, that among the people of 
 jVfrica, to the northward at least, the sole or the principal meal 
 is supper. Among some of the negro tribes, this indeed is not 
 merely the practice, but the very reasons for it are assigned ; 
 namely, the hazard or certainty of fever from eating in the heat 
 |>f the day. This particular fact was ascertained distinctly by 
 | Hajor Denham ; and, whether it is urged in his printed account 
 Is it merited, or not, it is derived, I am informed, from his strong 
 
 S 
 
131 PROPAGATION OF 
 
 personal declaration, that he attributes his own preservation to 
 his having thus followed the native philosophy in his practice. 
 
 I need not protract this detail ; but it interests our colonists or 
 residents in all the hotter climates, and those in the West Indies 
 and India in particular, to inquire whether their principal suffer- 
 ings have not rather arisen from transferring their gross and inju- 
 dicious European habits to these countries, than from the mere 
 climate; whether they are not, in reality their own destroyers, 
 from the indulgence of their appetites and improper habits. It 
 has indeed been often said, that very frequently among our armies, ' 
 and very widely also among the planters of the West Indies, the 
 usages as to diet and mode of life are such as would be ruinous 
 to health, even in Europe ; far more under all the circumstances, ; 
 and in the climates, where such a luxurious manner of living is 
 the habit of society. 
 
 And that this observation is not an unfounded one, will be con- 
 firmed on a comparison between our own colonists, as well as 
 those of Holland and the northern voracious nations in general, L 
 and those of France, and apparently also of Spain ; though with a 3 
 want of observation not uncommon, added to the desire of find 
 ing excuses for self-indulgence, the superior durability of the two t 
 latter people as tropical colonists, has been attributed to the 
 change of climate being, as to them, less. They who will reflect 
 on what has now been said, and then compare the actual life of a 
 French colonist with an English or a Dutch one, will probably 
 accede to the conclusion which is here drawn. 
 
 I may also borrow a fact to the same effect from Captain 
 Symes, and respecting a people not less delighting in voracious 
 eating and animal food than those to whom I have been alluding. 
 He says, it is true, that the lake in Ava which was his abode du- 
 ring his embassy, was not unhealthy ; but the Chinese ambassa- 
 dors, nevertheless, all died of fevers from eating, while his own 1 
 people escaped, in consequence of better discipline : proving the' 
 fact under review, and also suggesting that his report as to the 1 
 salubrity of this situation was not to be taken in a rigid sense, but 
 in a comparative one. 
 
 If, in examining the propagation of Malaria from chemical con-^ 
 siderations, I have also been compelled to notice its checks, this 
 is the proper place to state one fact at least which bears upon 
 this subject, respecting which there can be no doubt , while 1 
 could without difficulty, support it by other parellel ones. 
 
 I have given an account of the propagation of Malaria througt 
 Rome, and have therefore been in some measure compelled t( 
 anticipate this particular subject. Here, the Judaicum, whicl 
 might be expected to suffer as well as the streets around it, is al 
 ways, as I am informed generally may at least be believed, fre< 
 from the diseases in question : and what the confinement air? &*' 
 
MALARIA. 135 
 
 of that place is, needs not to be stated to those who know Rome, 
 even by reading. It might not be safe to conclude from this- sin- 
 ! gle fact, that the propagation of Malaria cannot take place through 
 j similarly crouded streets or towns ; but the general truth is con- 
 firmed by so many more of the same nature, and in so many pla- 
 ices, that it may safely be considered as one of the established 
 rules relating to the transference or effects of this poison. 
 
 Nor does it seem difficult of explanation ; of that general ex- 
 planation at least which is all that we can expect on a subject 
 j where our knowledge is as yet so short of accuracy. The Mala- 
 jria must be a chemical compound, and therefore decomposable ; it 
 lis, experimentally, decomposed by fire and smoke, and it is there- 
 'ifore probable, that, amid the unknown mixture which forms the at- 
 ijmosphere of crowded streets or habitations, it is actually destroyed. 
 If, at present, we cannot speak more precisely as to the cause, 
 'the fact itself is, in practice, one of considerable interest, and also 
 of some value. Historically, we can never believe that the fe- 
 jvers which raged in Rome annually during the time of the Ro- 
 man empire, that the month which " adducit febres et testamenta 
 ( resignat, ,? the " Septembres horas" which drove all the opulent 
 Trom the city to take shelter in their country houses, was as fatal 
 |to the lower citizens as to the upper ranks, however the depress- 
 ed state of these, under a patrician nobility and a tyrannical go- 
 vernment, with the want of statistical notices on that subject, 
 may have rendered their sufferings despised, and left our own in- 
 formation imperfect 
 
 It is far more probable that they did not suffer like the more 
 wealthy ; and from the causes now laid down : and the history of 
 Rome as to health, then, was probably much the same as it is 
 now ; the present fact establishing the former probability. It 
 was, literally, Death knocking at the door of the opulent to spare 
 the mean ; not marching " sequo pede" through the " pauperum 
 tabernas regumque turres." And that the causes of prevention 
 in question did exist as to the lower orders, seems plain from a 
 computation of the population of Rome during the most flourish- 
 ing state of the empire, and from a comparison of this with the 
 dimensions of the city ; a computation for which 1 may refer to 
 Gibbon's essay, proving that the people were condensed into the 
 floors of lofty houses, as in Paris; and apparently also into crowd- 
 ed and narrow streets, as in Athens, the Wapping of Greece. Be 
 this as it may, the poverty of the great mass of citizens in Rome 
 at that time, and indeed at all others, is evinced by the barbarous 
 practice of eleemosinary distributions ; which proves, not only a 
 want of industry as well as of employment, but an entire debase- 
 ment of the feelings, and, consequently, of all the habits of life. 
 They were poor, and their habitations could not have been better 
 
13G PROPAGATION OF 
 
 than their food. It would he a matter of some surprise, if any 
 part of ancient Rome inhabited by the lower herd of citizens, 
 was even as convenient as the present retreat of its wretched 
 Jews. But I must avoid the hazard of running too deeply into 
 antiquarian researches ; it seems probable that a parallel case ex- 
 ists in our own capital. 
 
 If, as having been a subject held out to public as well as to offi- 
 cial medical discussion, I formerly noticed the ill health which 
 had unexpectedly appeared in the Penitentiary, I am bound to 
 remark, that in rendering it independent of the streets, the inten- 
 tion was good in more modes than one : since neither was Mala- 
 ria suspected, nor was the nature of the remedy which I have 
 been discussing, imagined. And while it affords a striking ana- 
 logy to the case of the Salpetriere, though the diseases were dif- 
 ferent, we may now see why this ill health does not invade the 
 crowded streets of this division : since a Malaria which, in far 
 greater virulence, cannot enter the Judaicum of Rome, must ef- 
 fectually be repelled in this closely inhabited spot. Thus one 
 class of misery becomes the remedy for another : while this ex- 
 plains the doubts of those who, unacquainted with the nature of' 
 this check, not unreasonably denied the very existence of the 
 cause. If its operation has been now terminated by a better diet 
 and other regulations, the reasons are familiar to physic : while 
 it is also quite possible that either the production or the propaga-: 
 tion of the Malaria, or both, have been diminished by some oi 
 the changes formerly pointed out. 
 
 ^ I am quite aware that I ought to have quoted many more sp< 
 cine cases than I have done, not only on this point but manj 
 others, as examples in evidence ; particularly upon those least 
 suspected situations and soils productive of Malaria: since, fron 
 not having done this, 1 have incurred the hazard of diminishing 
 the credit due to these statements, and, consequently, of impe( 
 ing that utility which has been my sole object ; to say nothing oi 
 the personal inconvenience that ought to result from asserting 
 more than I have proved. For the former I grieve ; the latter 
 must bear : but it is not for want of local proofs that they are nol 
 produced; as I could have amply established in this manner eve 
 ry thing that has been advanced*. But when the sole intention ( 
 this essay had been the public good, the diminution of sicknes 
 and suffering, I could not but recollect that in pointing out insz. 
 lubnous spots, though for the mere purpose of evidence, and foi 
 the sake of teaching the people, by examples, how to recognize 
 the characters of such places generally, individual inconvenience 
 or even injury, might perchance have followed. 
 
 I trust that I have avoided this ; and it has assuredly not beei 
 tor want of anxiety : while, in as far as any occupation of land bj 
 
MALARIA. 137 
 
 means of new buildings, in any situation in England, is intended, 
 it can effect but good, to remind the public of this and the other 
 precautions which may be deduced from the different facts here 
 stated. Thus for example, the substitution of a spacious and airy 
 street for a narrow and ill-ventilated one, might, in such a situa- 
 tion, be hazardous, as the example of Rome testifies : and if there- 
 fore it is intended to occupy in this manner, any questionable 
 place, it would be prudent to commence by laying dry any lands 
 which are of a suspicious character ; because, in the views here 
 taken, they will, in some season or other, if not in every year, 
 become productive of Malaria and disease. 
 
 That I have not misstated the facts, nor the causes, as to any 
 part of England where they may occur, will be vouched by at 
 least every French and Italian physician accustomed to such 
 lands and to the diseases which are their produce ; while the en- 
 demic autumnal fevers, which, in the year 1826, amounted to al- 
 most an epidemic in so many places throughout the country, and 
 in some very particularly, which I ought to have here named 
 were it not for the reasons which I have just given, cannot fail 
 to convince those English practitioners who, from military and 
 foreign service, have been familiar with the disorders of hot cli- 
 mates; however little impression this circumstance may make 
 on others, and on those especially who follow the popular opin- 
 ions in considering them as typhus, or who, otherwise, under a 
 minor error, attribute the cause to heat simply, or to the use of 
 fruit, or to whatever else of this imaginary nature. And if, in the 
 last chapter, I stated the general revolution of increase which 
 Malaria might experience from the progressive embankment of 
 rivers, I should be deficient in the duty which I have here under- 
 taken, did I not point out how this very condition of things was 
 taking place in many parts of the Thames ; though little perceiv- 
 ed or understood by the people, nor justly apprehended except 
 by geologists and engineers. If I forbear to specify the exact 
 spots, however involving the health of the capital, for the reasons 
 just assigned, the mere pointing out the general fact and its theory 
 as it concerns us, will suffice for those who may be interested lo- 
 cally, and who may have it in their power to apply the remedies 
 by a more efficient and extended drainage ; not longer to be com- 
 manded for many places, by flood gates and low water canals, 
 and demanding now, what in reality these have long since done, 
 the use of lifting machinery. 
 
 It is so easy to apply the general principle in question to the 
 explanation of all similar cases, that I shall here terminate this 
 particular discussion, and proceed to examine that problematical 
 fact to which I have lately alluded, relating to the personal pre- 
 vention of disease under the presence of Malaria. The fact, as 
 
138 PROPAGATION OF 
 
 it is stated, is simply this ; that by surrounding the head with a 
 gauze veil or co?iopeum, the action of Malaria is prevented, and 
 that thus it is possible even to sleep in the most pernicious parts 
 of Italy without hazard of fever. In Malta and elsewhere, this 
 belief is universal : and hence the popular practice of covering 
 the mouth and nose with a handkerchief, in the morning on going 
 out, or in other suspicious circumstances : a practice, the efficacy 
 of which is attested, as far as popular belief can attest any thing. 
 Thus also, in Spain and Portugal, it is a common or universal 
 habit to draw the mantilla over the mouth when in suspected 
 places, as also in foggy weather and east winds. Perhaps how- 
 ever it is a fact yet wanting confirmation ; but it is not impro- 
 bable on theory, because we can thus conceive an atmosphere 
 from the lungs, accumulated within the veil, capable of decom- 
 posing the Malaria. A popular practice in fogs, in our own 
 country, that of applying a handkerchief to the mouth and nostrils, 
 may not therefore be so fanciful a prevention of disease as it is a 
 vulgar one ; however often misapplied. 
 
 On this subject, I may add that I have suggested to different 
 naval officers, the propriety of at least trying this experiment in 
 a manner and on a scale which could scarcely fail to give a true 
 result ; while if it did prove successful, its value would be far 
 greater than is easily imagined by those who are not acquainted 
 with the details of nautical service on the African coast and else- 
 where, and in the former, very particularly, in that destructive 
 service, the cutting of wood. It would be abundantly easy to 
 make the comparative trial on two boats' crews employed on the 
 same duty ; and as it much too often happens that every individual 
 from one boat is siezed by the fever after such an expedition, even 
 a single trial perhaps, or at least a very few, would determine 
 the question; while the experiment is amply justifiable, inasmuch 
 as it is not one which exposes life, but which attempts to preserve 
 it. As yet, I have not succeeded in procuring this trial to be 
 made ; and if the publicity which 1 am attempting to give to it 
 here, is not likely to be very great, it is still possible that the 
 hint may at some day reach the ears of those in whose power it 
 may be to put it into practice. 
 
 It is true that there is an objection to this opinion, founded on 
 a theoretical view of the action of Malaria on the body ; but be- 
 fore it is admitted as a valid one, it ought to be proved that the 
 theory is true. It is Brocchi who argues most strenuously to prove 
 that the poison is received by the skin and not by the lungs ; and 
 as the question is of some importance, I must both give and ex- 
 amine his arguments. 
 
 It is certainly not a point easy to prove by any direct means, 
 that the poison of Malaria is received by the lungs and not by the 
 
MALARIA. 139 
 
 skin ; yet it would be a very natural priori inference, that, of two 
 surfaces, that which is most perfectly exposed to the action of air, 
 which is infinitely the most sensible, which is also the most ex- 
 tensive, and which, lastly, does decompose the air which it re- 
 ceives, should be the real agent in the transmission of this sub- 
 stance. To argue from Richerand, as Brocchi does, that be- 
 cause (supposing it even true) the absorbents of the skin are most 
 active during sleep, and because Malaria attacks'a sleeping per- 
 son most readily, the poison must enter in this manner, appears 
 sufficiently puerile, when we know that the peculiar state of the 
 body in sleep, is favourable to the access of many other diseases. 
 And if, as is a prevailing opinion in many parts of Italy, and in 
 Malta also very especially, the practice of covering the mouth, 
 which. I have just noticed, does prevent danger, here is a direct 
 testimony for the reverse conclusion. 
 
 But it seems unnecessary to argue this point on the grounds of 
 physic or physiology ; since, with little of direct evidence, every 
 one will, as usual, conclude according to his favourite hypothesis. 
 Yet in as far as the writer in question attempts to support his 
 theory by the history of ancient Rome, his arguments appear suf- 
 ficiently weak. As I have remarked elsewhere, he tries to prove 
 that the difference of salubrity in the former and in the present 
 times, arose from the use of woollen clothing, or of the toga, by 
 the older Romans ; and, refining still further, endeavours to trace 
 the increasing severity, as he imagines, of febrile seasons in the 
 time of the empire, to the increase of luxury and the substitution 
 of silk and linen for wool ; attributing also, idly enough, the fact 
 that the inferior animals are not affected by these fevers, to their 
 furry or hairy coats ; an imaginary fact also, since I shall here- 
 after show that this is not true. 
 
 The period in question commences at the decline of the repub- 
 lic, as is evinced by the attack of Cicero on Cataline ; the toga 
 gradually giving way to a lighter garment, and the use of silk be- 
 coming still more common in the reign of Tiberius. It is how- 
 ever unnecessary to pursue this, nor to examine the collateral 
 arguments by which the opinion is supported ; deduced from the 
 fact that the rich only left the city, because, says Brocchi, their 
 light and luxurious dresses rendered them peculiarly or solely 
 susceptible of the fevers, and from others of equally little bearing 
 on the question. The rich migrated, while the poor could not ; 
 and to whatever other causes the relative states of health at the 
 various periods in question may be attributed, I have examined 
 them as far as they present any probabilities, in another place. 
 I shall only farther remark, that the time fixed on for the sup- 
 posed increase of unhealthiness, is precisely that when luxury 
 and ease, and I may add the new existence or increase of physi- 
 
1 10 . PROPAGATION OF 
 
 cians, rendered questions of sickness and health matters of more 
 attention than before ; and when also the increase of writers pro- 
 duced records which could not have existed at earlier periods. 
 
 But I think it fruitless to pursue further a speculative opinion 
 of this nature; admitting only, the propriety and utility of warm 
 or non-conducting clothing, even of wool if any one shall prefer 
 it, on the well known grounds that cold and wet, or exposure ge- 
 nerally, is injurious, as aiding the activity of all contagions or dis- 
 eases, and of Malaria and its consequences among the rest ; while 
 also capable, as I have elsewhere shewn, of renewing a fever of 
 habit without a fresh application of the primary cause : possibly 
 indeed, capable in itself of generating intermittents or the other 
 diseases of this class. 
 
 That I may not be obliged to recur to this question, namely, * 
 the mode in which the poison of Malaria is introduced into the 
 system, I may as well remark here also, that there is a third par- 
 ty which supposes that it acts through the intervention of the sto- 
 mach; while some, wishing possibly to reconcile or unite all 
 opinions, conceive that it acts on every accessible surface ; on 
 the skin, the lungs, and the stomach. That the plague, and that 
 contagious fevers in general are received through the stomach, 
 has, it is well known, been a very common opinion ; and there 
 are certainly not wanting facts to give a colour to such a theory, 
 though short of that evidence which should produce philosophi- 
 cal conviction, while not a little opposed by the well known ex- 
 periments which indicate the power of the stomach in decompo- 
 sing certain animal poisons. I need not re-examine so hacknied 
 a question; while, as I have just remarked, it is probable, that, 
 as is usual under defective evidence, each man's opinion will be 
 regulated by his affections for the one hypothesis or the other. 
 That my own opinions are undecided because the evidence is in- 
 sufficient, is perhaps apparent; however little that state of wil- 
 lingness to wait, may concern the reader. 
 
 It has been asked whether Malaria might, like contagion, be 
 carried in the clothes of a person, or retained, as all those are, in 
 a dead substance, so as to communicate the disease at a distance 
 of place and time. This is a question to which I alluded in the 
 commencement of this chapter ; and which, if I passed by it then, 
 I would gladly pass now, if I did not feel that it was necessary to 
 prove that at least I had not passed it from indolence, but from 
 the difficulty of saying any thing satisfactory respecting it. It 
 seems almost impossible to find an answer to this question, from 
 experience : as, in almost every instance where we might seek to 
 find it communicated in this manner, the fact that every individu- 
 al may have been similarly exposed to the original source of dis- 
 ease, renders the investigation nearly impossible. It is a doubt 
 
MALARIA. 141 
 
 that might perhaps be put to the test of direct experiment ; but I 
 cannot discover that any such trial has been made. It is perhaps 
 indeed more a question of curiosity than use ; though nothing is 
 useless in philosophy which tends to make us better acquainted 
 with the subjects of our investigations. If we could rely on pri- 
 ori reasoning, we should perhaps decide that this was possible ; 
 since we can see no cause why one compound gas should not 
 possess this property as well as another ; Malaria as well as con- 
 tagion. And there, for the present, must we rest. 
 
 If, as somewhat diverging from this question, that much more 
 important one, namely, whether the fever of Malaria can propa- 
 gate itself from one subject to another, is rather an inquiry belong- 
 ing to the medical division of this entire work, I know not but 
 that it may as well take its place here. That it has been a sub- 
 ject much discussed, and with no small energy, or even acrimony, 
 I need not say, while, as on many other much argued points, the 
 contending parties have often been divided, from neglecting to 
 commence by a mutual understanding of the objects in dispute. 
 Whether any particular endemic or epidemic was or was not a 
 contagious disease, is a somewhat separate medical question ; on 
 which I shall not now touch, as the inquiry here is of a different 
 nature. 
 
 The facts proving that remittents and dvsenteries unquestiona» 
 bly arising from Malaria, have, in their progress or continuance, 
 become contagious diseases, though not so originally, are numer- 
 ous, and rest on as good authorities as physic has to produce. 
 When I quote Pringle and Lind and Blane, referring to facts well 
 known to physicians, and which 1 need not therefore extract, the 
 authority seems not of a nature to be doubted ; though it is as po- 
 sitively contradicted by Pym and many more, as it seems to be, 
 very generally, in France. Nor is it easy to see where the objec- 
 tion lies. The assertion, or the fact, does not imply that the 
 fever of any one individual did reproduce, through his secretions, 
 a Malaria similar to the original one, and therefore a fever or dy- 
 sentery of Malaria ; but merely, that, under such a state of dis- 
 ease, the morbid secretions in question became the source as well 
 as the matter of the contagion ; as happens even with respect to 
 healthy persons under peculiar and well known circumstances. 
 The original disease dissappeared, and a new one was produced ; 
 or, in the morbid individual, one fever was converted into ano- 
 ther of a different character ; just as, under other diseases, a con- 
 tagious hospital disorder of any nature may be superinduced on 
 the first, even to its extinction. Or, it is not that the remittent 
 fever of marshes is contagious, but that it may become, or give 
 way to, a contagious fever. It is perhaps a certain heat of tem- 
 per excited in maintaining a recent hypothesis, which seems to 
 
 T 
 
1 1*J PROPAGATION OF 
 
 have viewed this subject in a different and unfounded light, lead- 
 ing to much superfluous and some angry writing. 
 
 I have reserved to the last place one of the most difficult ques- 
 tions relating to the propagation of Malaria; a question in which 
 is involved that of the peculiar effects of east winds; and it re- 
 lates to the distance to which the poison can be transported. It 
 is admitted that the subject is obscure and disputed ; but that 
 must not be an obstacle in the way of its examination. 
 
 While it is asserted by many writers that it cannot be trans - 
 sported beyond a very moderate distance from the place of its 
 production, or that it is almost limited to the very spot where it 
 is formed, there is evidence to prove that this is a groundless opi- 
 nion or the result of bad observation : while, like much more of 
 assertion, on this and every other subject where medicine is con- 
 cerned, it may be traced to a far too common practice among 
 writers, on this, and on other physical subjects : when, unable 
 to throw light on a difficult inquiry by their own knowledge or 
 powers of reasoning, they attempt to attract attention by opposing 
 whatever is advanced by research and ability. 
 
 To commence with an indisputable fact ; what I have already 
 noticed respecting the propagation of Malaria from the Thames 
 over the hills of Kent, proves that it can be conveyed through 
 the winds, to distances of some miles from its original place of 
 production ; while there would be little difficulty in finding num- 
 erous other similar instances, and equally marked, And as, in 
 this particular case, the original Malaria, whether as to quantity 
 or virulence, cannot be very considerable, it is easy to believe 
 that in more favourable circumstances, it may be transported to 
 distances far greater. 
 
 And, by analogy, we can see reasons in confirmation of this 
 opinion, as it is further supported by certain meteorological facts. 
 Odours are conveyed, notedly, to great distances through the air, 
 and often in a very concentrated state ; and it is not easy to con- 
 ceive how the quantity of matter in Malaria can be much less 
 than the quantity of the matter of odour, while it is certain that 
 inappreciable quantities of this, as of all contagions, are suffici- 
 ent to produce their respective diseases. - If the " Sabean odours'' 
 and " spicy gales' 1 of Arabia range the seas of that shore rather 
 in poetry than in reality, it is certain, not only that dogs can smell 
 the land from sea, long before it is visible, and at very great dis- 
 tances, but that it is sensible to our own organs when many miles 
 distant. And thus also can the smell of the sea, which, in reality, 
 is the smell from fish, be often perceived at great distances in- 
 land ; as the odour from a large fish at sea, from a whale or a 
 shark, is often extremely powerful, and even offensive, as far off 
 
MALARIA. 143 
 
 as the spouting, or the animal itself, is visible from the mast 
 head. 
 
 The meteorological argument rests on the distances to which 
 local or limited fogs can be carried by the winds, and to the often 
 enormous ones to which even a very small cloud can be trans- 
 ported, without the loss of its integrity. Here, it is plain, an ex- 
 tremely tender aggregation of a substance which may almost be 
 considered a gas, is maintained entire, by some internal affinity 
 of its own, while floating in another gas, and subject to a degree 
 of mechanical violence, independently of destructive chemical 
 actions easily conceived, which should be supposed capable of 
 causing its immediate dispersion. 
 
 Why might not a Malaria possess the same means of preserving 
 its integrity, and the same power of undergoing transportation ? 
 JNo one dares decide on the impossibility ; yet that, it must be 
 owned, is not a proof that there is this power. It is however 
 rendered directly probable by the following fact. It has been 
 shown that Malaria combines especially with a moist atmosphere, 
 or with fogs and mists. It is, in reality, combined with a cloud: 
 and since that is indefinitely transportable, we can see no reason 
 why the Malaria should not also be transported with it. If not 
 decomposed by this union at first, there is no apparent reason 
 why it should be decomposed afterwards ; and thus it may travel 
 the atmosphere, under the protection of its original receptacle, to 
 distances which we can scarcely venture to limit. 
 
 And, to a certain extent, experience proves that this actually 
 happens ; that the cloud is not only the vehicle of the Malaria as 
 it is its receptacle, but that it does transport this poison to consi- 
 derable distances. This is precisely the popular, as well as the 
 philosophical experience, respecting the diseases wafted by fogs ; 
 and the only question that remains, relates to the distance. Theo- 
 retically, we might decide, that as far as the fog produced by, or 
 over, a land of Malaria travels, so far might the Malaria itself be 
 carried, even without the aid of this vehicle ; and it only remains 
 to inquire what experience there is as to the actual distance so 
 travelled ; a circumstance to be determined only by examining 
 into the diseases produced in this manner. On this subject, I can 
 find no observations of any great value or precision ; but as it de- 
 serves to be examined, these suggestions may perhaps prove a 
 stimulus to its future investigation. 
 
 Yet I must offer a few remarks that bear on this fact, of which 
 the first appears sufficiently precise as far as it extends ; the latter 
 will doubtless be a subject of dispute. 
 
 Seamen observe that the land breeze in tropical climates brings 
 off with it the fevers of the shore : and indeed were this not the 
 case, we could scarcely account for the production, in certain 
 
I 14 PROPAGATION OF 
 
 instances, of the common remittent fevers at sea, when in tropi- 
 cal climates ; while, partly perhaps from inattention to this fact, 
 though more, doubtless, from a confusion of ideas respecting fever, 
 this disease is often mistaken for contagious typhus. I allude here 
 to the appearance of fever in clean ships, or in cases where there 
 has been none while at sea, but where it has appeared on coming 
 into harbour or nearing the land ; because I have formerly shown 
 that bilge water will, in all probability, often explain the produ- 
 tion of fevers when in the ocean or far from land. I have exa- 
 mined voyages and made inquiries in vain, to find a large limit of 
 distance as to the appearance of the remittent fever at sea; but 
 have had little success, from the want of corresponding entries in 
 the log book, to compare with the event. If I have imagined 
 that I could produce examples of this occurrence at far greater 
 distances than has ever been imagined, I prefer avoiding to insist 
 on such cases ; while perhaps others, hereafter, may be induced 
 to turn their attention to this subject, and to note facts that shall 
 have the sanction of accuracy. But I must also observe, that the 
 fact just alluded to, the production of fevers by bilge water, will 
 always throw a doubt on any conclusions to be drawn in this 
 manner, or perhaps impede the investigation altogether ; unless 
 we could at the same time be assured of the cleanliness of the 
 vessel in question. 
 
 But however I may have failed, myself, in procuring such evi- 
 dence on this subject as I should have desired, I have not the 
 least doubt that this information is to be found among naval offi- 
 cers and surgeons ; and while the present discussion may here- 
 after induce others, in the way of criticism or assistance, to give 
 to the world their yet unpublished knowledge regarding it, I shall 
 not be surprised to find that to whatever distance a tropical land 
 wind reaches, under a favourable state of atmosphere, at that 
 point of a cruize has the fever also appeared in many instances. 
 That within moderate limits, such as four, five, six, or more miles, 
 the fever, or the Malaria, is blown off the shore to ships, I have 
 found distinctly recorded in the ships' journals in different instan- 
 ces ; as I have also been repeatedly informed that the smell be- 
 comes immediately sensible ; while officers aware of this danger 
 on these coasts, quit the deck to go below, at the moment they 
 perceive this change to have taken place, or even, on some oc- 
 casions, weigh their anchors and run to sea. And though I have 
 quoted one specific case of this nature in the medical part of this 
 work, the accuracy of proof which it affords is so remarkable, that 
 I must notice it here. In this instance, with a healthy ship and 
 crew, anchored at least four miles from the shore, a sudden 
 change of wind brought out the smell of the land, on which or- 
 ders were immediately given for weighing ; while, even before 
 
MALARIA. 145 
 
 the cable chain could be cleared, most of the men working at it, 
 who were the only ones first permitted on deck, were seized with 
 disease which proved the fatal cholera to the greater number. 
 
 Of other observations, I must give such as I can find ; while, 
 if I do not place any great confidence in their value as to the 
 question at large, I am justified in this, from the manner in which 
 they are recorded, and in which the supposed limits were at- 
 tempted to be ascertained. That they do not even approach to 
 the maximum, which is the question before us, is at once evi- 
 dent. 
 
 Monfalcon, speaking very vaguely, and without adducing any 
 proofs, presumes that the Malaria never reaches above five or 
 six hundred yards perpendicularly on the acclivity of a mountain, 
 nor beyond three or four hundred in a horizontal direction, pro- 
 vided it be calm. This may possibly be an approach to truth as 
 it relates to the former case ; but in a calm, there is no apparent 
 reason why it should even extend so far from the place of its pro- 
 duction, since there is no horizontal current in this case, while 
 there is very often a vertical one in the other. ¥/hen, in the 
 West Indies, it has been plainly ascertained to reach to three 
 miles at sea, it is Lind (I think) who seems inclined to make this 
 a maximum ; yet from facts far too partial and limited to permit 
 such a conclusion. Another observer, equally decisive, attempts 
 to establish a maximum from a single observation, namely at 
 Walcheren ; and thus, by others if not by him, 3000 yards has 
 been fixed as the boundary which it is not to pass. If it spreads 
 three miles in the West Indies, and if, similarly, it is proved that, 
 from the Lake Agnano, it reaches three miles to the convent of 
 Camaldoli, seated on a high hill, it is plain at any rate, that the 
 maximum derived from Walcheren is too low ; while, though I 
 cannot find a definite point fixed by the different observers who 
 appear to have taken views of this subject not unlike my own, I 
 may name Volney, Orlandi, Senac, Fodere, Laneisi, as admitting 
 that it spreads to great distances ; as is also believed very exten- 
 sively in Italy, in Corsica, in India, and elsewhere. I may pro- 
 ceed to state what further has occurred to my own reflections on 
 the same subject. 
 
 The first fact is derived from our own climate, and it relates to 
 the appearance of the diseases of Malaria on our eastern coasts in 
 east winds, particularly in spring ; since, as far as my observation 
 goes, this transportation is limited to intermittents ; a fact for 
 which the reasons will shortly be sufficiently obvious. And I 
 must here take, first, the case of a fog or cloud, as being the sim- 
 plest, and as the rigid continuation of the present inquiry. 
 
 It consists with the experience of all the inhabitants of our eas- 
 tern shore, that the ague often appears with the fogs of spring 
 
1 lf> PROPAGATION OF 
 
 which arrive from the sea; that, in fact, they are brought in that 
 fog which is popularly supposed their real cause. Now if in Es- 
 sex or Lincolnshire, there are cases w r here the Malaria might be 
 generated from the immediate land, appearing to have arrived in 
 the fog, only by a deception, there are points on the coasts of 
 Norfolk and SuiFolk, as in many other places, where no local Ma- 
 laria exists for many miles, and in which, if the agues did not ar- 
 rive in the sea fog, they could not appear at all. And this is no 
 less true of the eastern coasts of Scotland where ague, as a local 
 endemic disease, is unknown, and where no Malaria is generated. 
 
 What then is the solution of this ? Obviously, that on which I 
 have just speculated, and which these facts confirm. Holland or 
 the shores to the northward are here probably the sources of the 
 Malaria, and it is transported to our own coasts in the fog and by 
 the east winds. It is never brought by wet winds and fogs to the 
 western shores, because there is no western focus"^* Malaria ; 
 nor by northern ones, for the same reason. To assign the cause 
 to the east wind simply as such, is to assert that the atmosphere 
 is itself a Malaria, or that water is the poison ; since, of these 
 two things, the chemical compound, air, and water, is pure wind 
 compounded : it is to abandon the whole theory of Malaria, sup- 
 ported as it is by the most uncontrovertible proofs, or it is to as- 
 sert that of which there is no proof, nothing but the assertion of 
 bad observation ; that the air alone in a particular state, or mere 
 cold and moisture, will produce original ague. If it did this, why 
 is it not as common in the frozen or cold regions as with us ; why 
 does it increase with heat and vegetation ; and why does it attend 
 exclusively the season of vegetation, and why do not the dry bar- 
 ren deserts of Africa produce the same fevers as its swamps and 
 jungles ? The air and its water are vehicles of poison, not poison ; 
 mediums for communicating diseases, not causes of disease. After 
 this, why persist in that undiscriminating and slovenly philosophy, 
 if philosophy it may be called, which attributes the diseases of 
 Malaria to wind and fog, because they chance to come from the 
 east rather than the west. W^ere such windier se, the cause of 
 fever, when and where would the lands under the trade wind be 
 exempt from disease, and how should even a ship escape amid 
 the equatorial seas ? St. Helena would never be exempt from 
 agues ; and the family of Napoleon at least, exposed to the per- 
 petual south-easterly fogs at Longwood, would scarcely have 
 avoided this fate ; whatever security he might have acquired from 
 having breathed his first air at Ajaccio. 
 
 This question is so important in a merely medical view, that I 
 must here urge it, since it is one that will not recur in the future : 
 parts of this essay. It is from carelessness, or from want of ob- 
 servation and of reflection, as well as from the habit of following 
 
MALARIA. 147 
 
 the phraseology of medical schools instead of reasoning, that phy- 
 sicians, and the people in consequence, persist in talking of cold 
 and moisture, and moist winds, and east winds, and fogs, as the 
 causes of intermittent ; having, with somewhat more of reason 
 maintained, and possibly, as to some points, proved, that they ge- 
 nerate sundry other diseases ; and thus confounding both causes 
 and effects, because these are particular winds and because these 
 are accompanying disorders. The queries that I have just put on 
 this subject can be answered decidedly. The east wind is as 
 cold and as bitter when blowing across a frozen continent as it 
 can ever be ; yet it produces no intermittent fever, because vege- 
 tation is dormant, and decomposition is at a stand. If it blows 
 across an extent of even unfrozen land in winter, it may cause 
 diseases, but it brings no intermittents, for the same reasons. Here 
 it may be moist, and even foggy, as well as cold, as it is when it 
 blows across an ocean ; and in this latter case, it does not pro- 
 duce intermittents, even in summer and when vegetation is active, 
 provided it has swept no lands in its way. To be injurious in this 
 sense, it must be a land wind while it is an east wind, and it must 
 also blow, in our half of the globe, between March and October ; 
 while, if it conducts fever better than another wind, it is only 
 when it chances to be a better conductor than that one, or, when 
 it is a moist wind. 
 
 But it is not always a moist wind ; far from it : being com- 
 monly, in summer, the driest of winds, just as it forms, in the 
 same manner, the burning and absorbent Harmattan in Africa : 
 and when it is such, any other wind may exceed it in conducting 
 power, while that will become the wind of intermittents ; the 
 very east-wind, as to all its morbid qualities, of the vulgar, pro- 
 vided it also traverses a land generating Malaria. Hence, as I 
 shall presently show, does it arise, that even the east winds from 
 Holland which bring intermittent in spring, do not equally bring 
 the autumnal fevers ; because, even when they do blow, being at 
 the same time less frequent and less rapid in movement, they are 
 comparatively deprived of that especially conducting, and, chemi- 
 cal power, which they derive from their union with hygrometric 
 water. 
 
 In addition to what I have more generally said on that subject, 
 it might be shewn by a geographical detail, for which, could it 
 even now be thought necessary, I dare not occupy room, that the 
 action or effect of the east wind is not the same everywhere, and 
 that, in the production of the diseases of Malaria, its power de- 
 pends on the relative position of the poisonous lands and the per- 
 sons suffering. It must be sufficient to point out one, almost at our 
 own doors. In French Flanders, it is the south and the south- 
 west winds that propagate the diseases of Malaria ; and the rea~ 
 
148 PROPAGATION OF 
 
 son will be evident on inspecting the geography of this tract. 
 And there, it is the north, and also the north-east, which remove 
 them, because they blow from the sea ; though charged with fogs 
 to darken the whole land. This is the true view and the philo- 
 sophy of every case. It is not quoad fog, any more than quoad 
 east, that either the fog or the east wind is the parent or vehicle 
 of fevers : it is in the sources of both that we must seek for the 
 true causes, or in the lands which, if not their sources, they sweep 
 in their progress. 
 
 But I must now examine this question a little more freely, and 
 inquire somewhat further respecting the east wind, simply, and in- 
 dependently of the transportation, by its means, of distinct fogs or 
 clouds. 
 
 It is a popular observation that the east wind itself, in our own 
 country, at least in spring, is the cause cf agues ; and an experi- 
 ence sufficiently extensive and accurate proves that this observa- 
 tion is well founded : while it is not a fact, after what I have just 
 said, requiring detailed proofs or a more minute statement. The 
 opinion, or the fact, as to other countries, involves too wide an 
 extent, as it is also too difficult to verify, and I must therefore 
 pass it over ; while the object here being to prove the general 
 principle, it is sufficient if it can be demonstrated from this select- 
 ed case. 
 
 Now we must here distinguish before we can proceed. If we 
 take the higher and western part of Lincolnshire, for example, 
 the east wind that reaches it must cross the fens not far distant. 
 This may be a very ordinary case of the propagation of Malaria 
 by winds. Thus it is also for the eastern side of London, exposed 
 to the transported Malaria of Essex, It is not always a pure case 
 when the inland districts cf England suffer. 
 
 If it is a collateral remark, it is not an uninteresting one, at 
 least to the people of London, that, at all times, the seasons of 
 remarkable east winds have been its seasons of intermittent. This 
 was the fact with regard to the years 1765, 1 766, 1782, and 1308 ; 
 and it has been similarly the case for these two or three years 
 past, as, for one of these at least, the records of the London Hos- 
 pital will particularly testify. And it is further remarkable, that, 
 in some of those years, the lands to the eastward that used to ge- 
 nerate intermittents only, produced continuous and remitting fe- 
 vers. Here, among other matters, while transportation is proved, 
 it is also apparent, as has been here remarked in different places, 
 under varying circumstances, probably of quantity or inten- 
 sity, the same land, and in the same season of the year, produces 
 bothagu^ and remittent or continuous fever ; and that the differ- 
 ence betw een ion and concentration in the Malaria, will be, 
 
MALARIA. 149 
 
 in effect, the difference between intermittent and remittent fe- 
 ver; that is, supposing this to be an unvarying compound. 
 
 But if, returning to the question in hand, we go forwards even 
 to the sea side itself of the eastern coast, we find the same rule 
 prevail as in the more marked instances of fogs. A simple or 
 transparent east wind brings the diseases of Malaria, at least in 
 spring; for the distinction is important, as 1 have just shown, be- 
 tween this season and the autumn. Here, as in the former case, 
 if there could beany suspicion that the diseases arose out of a 
 Malaria produced in the immediate soil, it is removed by the fact 
 of their occurring in Scotland, in places where that poison is to- 
 tally unknown, and in similar clear states of the atmosphere. 
 Thus, for example, on a sudden change of the wind to the east, 
 soldiers in the Castle of Edinburgh, susceptible of the disease 
 from former habits, become immediately affected, when a north 
 or north west wind, equally cold, does not produce the same ef- 
 fects : while, in other places equally free of the endemic disease, 
 a new disorder is even produced in a new subject. 
 
 The fact being thus supposed established, there appears no rea- 
 son why it should not deserve credit, from general considerations ; 
 or we may try the question according to principles or theory. I 
 have shewn that a moist atmosphere is a peculiarly apt conductor 
 of Malaria ; and this is the general character of the east winds of 
 spring. If they can conduct it to certain distances in the dry 
 state, they may convey it much further in the moist one ; while 
 we must also not forget, that the mere circumstances of cold and 
 moisture may possibly render the body more susceptible. And 
 if the clear tropical winds can convey remittent far to sea, it is 
 far from unreasonable to suppose that the east winds which reach 
 us from Holland, may bring the Malaria of that country with it, 
 though they should not convey a fog or a cloud at the same time. 
 
 In a meteorological view, there are other reasons also in favour 
 of the possibility of such a distant transportation. One of these is, 
 the rapidity with which winds travel, and, what is more impor- 
 tant, the singularly steady, linear and horizontal direction united, 
 which they sometimes assume, so far different from that intricacy 
 which was formerly pointed out. And here it is peculiarly wor- 
 thy of regard, that while this steadiness of parallel flow is much 
 greater at sea than on shore, so is the east wind that one which is 
 particularly steady and uniform in its current, and most of all in 
 those seasons in which it blows continuously for a long period ; 
 the very fact in the case of the east winds of spring. Under such 
 circumstances, though there were no facts to prove it, I cannot 
 see why Malaria should not be conveyed in a moist east wind, to 
 distances even far greater than that between Holland and England, 
 and without such a dispersion as to destroy its powers : as, in the 
 
150 PROPAGATION OF 
 
 same circumstances, such dispersible substances as swarms of in- 
 ire even brought over in solid columns, and not unfrequent- 
 lv in narrow ones. 
 
 Let me make yet one remark of a meteorological nature which 
 may throw some additional probability on this view, even though 
 the tact itself should be more rare than I believe it to be. In a 
 very different work from this, (on the Highlands of Scotland) 1 
 have shewn that a current of wind will sometimes be found, blow- 
 ing for a considerable time, with great steadiness and rapidity, in 
 a straight linear direction ; occupying an undefined and undis- 
 coverable space longitudinally, yet not exceeding a mile or two 
 in breadth, while accurately separated on both sides from a calm 
 or still atmosphere, or producing there nothing at least but that 
 narrow eddy which is an inevitable consequence of such a state 
 of things. And I have, in the same place, further shown, that two 
 such currents will thus blow, of similar dimensions and rapidity, 
 in directions exactly the reverse of each other, and also in con- 
 tact, or as nearly so at least as that can be proved by ihe ma- - 
 noeuvres of vessels under these circumstances. And lastly, I have 
 there shown that such currents will even cross each other's 
 courses, as apparently unimpeded, or undisturbed, as this can be 
 proved by the same mode of investigation. 
 
 The conclusion from these facts, as to the question before us, 
 is not unimportant. It is plain that in all these cases, each sue- o 
 cessively rising in value of proof, a mass of air in motion possesses 
 some principle of integrity, self attraction, or resistance to the 
 surrounding fluid or forces, whether chemical or mechanical, ca- : 
 pable of preventing its dispersion, or its solution in, or mixture 
 with, the surrounding atmosphere, even amid the most appare: 
 disturbing causes. It is like the case of a cloud, which thus tra-i 
 vels through many miles of atmosphere, even when extremely 
 minute, and when surrounded also by other clouds, without either 
 mixing with them, or losing itself among them, or in that air which, 
 under some other condition, becomes its rapid solvent. This be- 
 ing so, w ? e can scarcely avoid supposing, that in the case of the' 
 wind or of the cloud, or, whether the water contained in the- 
 stream of air is invisible or visible, any given portion of that wind* 
 will keep its relative place as to the rest, during its flow, just as 
 the cloud preserves its place, with its integrity, in the stream by 
 which it is conveyed : or that such portion will arrive at its de- 
 stination as independent or entire a body as it arose, and conse- : 
 quently, that the same will be true of the whole cum 
 
 The practical conclusion as to the question under review, i? 
 obvious: and it is, that should such a current contain Malaria - 
 having arisen in a soil capable of generating it, or having passed 
 such lands in its course, it rnav carrv, and can indeed scarceh 
 
MALARIA. 151 
 
 fail to transport, that substance to the most distant point which 
 it is destined to reach ; since at any point of its whole journey, 
 it is precisely the same air and the same body of air, in the whole 
 and in all its parts, as it was at any other point. Coming from 
 Holland therefore, any part of such a current should produce the 
 same effects on him who may be exposed to it, as if he had met 
 it in its native marshes ; just as it would have been the same 
 whether he had breathed the cloud whose motions he has traced 
 through miles of air, on the mountain where he stands or on that 
 where it was first formed. As a further illustration of this, I shall 
 only add, that as it is probably to similar narrow and parallel cur- 
 rents that we must often ascribe the narrow columnar flights of 
 migrating insects just noticed, so this seems to show a similar 
 state of interior integrity and steady relativeness of place among 
 the parts of such a stream. 
 
 I need not pursue this particular subject further, and I will 
 gladly leave it, even to the controversy that it will probably ex- 
 cite; indifferent to its standing or falling, provided the truth, 
 whatever that may prove, is elicited. There is nothing but truth 
 in this world which deserves the pursuit of a wise man : and to 
 him, attain it who may, it is equally valuable. 
 
 But I must yet answer an objection ; which 1 bring forward 
 myself, lest it should be overlooked by others. If the east winds 
 of spring bring intermittents from Holland, why do they not bring 
 remittents in autumn? The answer does not appear very diffi- 
 cult ; while, if I have already been compelled to anticipate it, I 
 must place it here in contact with the objection. 
 
 It is a common opinion that the east wind is always of the same 
 quality ; always equally injurious or disagreeable, always moist 
 and harsh. It is even a proverbial error, and an error of a wide 
 nature ; since it is maintained, that, all over the world, in all pla- 
 ces, and in all seasons, it is sufficient for the wind to be east to 
 be always of the same quality ; always disagreeable and always 
 injurious. Such, in a thousand other cases than that of the east 
 wind, is the sweeping nature of popular and ancient dogmas. 
 And yet it is not a vulgar dogma ; since it has been stated ex ca- 
 thedra by professors of natural history, since it has been asserted 
 by meteorologists of the highest name, and has even been held 
 out as a problem for solution. It would have been well to have 
 ascertained the fact first ; as has proverbially been said of many 
 others. It is like the wind that must change with the moon, the 
 storm that must follow a red sun-set or a halo ; one of the endless 
 superstitions by which the world is governed, not only in physics, 
 but in morals and politics. It is the balance of trade ; and, like 
 the balance of trade, the wisdom of our ancestors will some day- 
 become the jest of their posterity. 
 
152 PROPAGATION OF 
 
 In summer and hot weather, the east wind is often as notori- 
 ously dry, as it is moist in spring and in wet seasons. It is the 
 driest of winds ; it is even, as 1 have just said, the Harmattan of 
 Africa. It is the wind which, with us, attends, produces, the 
 burning heats of our burning summers ; as it is the very cause of 
 the extreme power of the sun, from the facility with which, ow- 
 ing to its freedom from water, it transmits light or heat. It would 
 be singular indeed, if winds of such opposite properties as the east 
 winds of March and those of July, should have the same effects 
 and produce the same sensations, because, in both cases, the di- 
 rection happens to be towards the west. We must leave this phi- 
 losophy to the vulgar, to whom it belongs : the point which I am 
 to prove is, that the conducting power as to Malaria, of a summer 
 east wind, cannot be the same as that of a spring or a winter one, 
 because they are different chemical substances ; and hence it is 
 explained why the remittent does not travel like the intermittent, 
 or why Holland cannot transport to us its Walcheren in August, 
 as it sends us the agues of its ditches in spring. 
 
 Enough of this subject : but I must hazard another remark on 
 the east wind, though it is rather of a medical than of a purely 
 physical nature ; while it is not such as to have properly found a 
 place in the second part of this essay. 
 
 The east wind is a popular grievance ; every one suffers, or 
 thinks that he suffers, from it; for it is sufficient if some can talk 
 where others feel. Imagination is worth a great deal in all such 
 cases. Every one indeed may feel its dampness and its cold, and 
 its cutting asperity ; and there are some who may really suffer 
 more deeply in their general feelings as to health or common en- 
 joyment, from this cause. So may it produce real diseases ; for 
 the application and the continuance of cold and moisture, par- 
 ticularly under the act of perpetual renovation, are not inno- 
 cent. 
 
 On these, it is not here my business or design to dwell. But 
 there is somewhat more behind ; indefinable or undefined suffer- 
 ings, too often the subjects of ridicule or doubt to those who have 
 not experienced them, sufficiently serious to the unfortunate who 
 are their victims. The supposed nervous and the supposed hy- 
 pochondriacal are here among the chief sufferers ; and long as 
 these have been the jest of prose and poetry alike, the jest of rude 
 health and selfishness and ignorance, who shall dare attempt to 
 claim some compassion for them, or to prove that they are suffer- 
 ers in the body and not in the spirit alone ? even were this last a 
 fit subject of jesting. 
 
 I am not going to deny that the common and obvious proper- 
 ties of the raw east wind may painfully affect constitutions of the 
 description now mentioned; but what I do mean to say, and what 
 
 I 
 
MALARIA. 153 
 
 I hope to demonstrate more fully in the second part of this essay, 
 is, that in many of these cases, the real effect produced by the 
 east wind is the renewal of a chronic disease, which, in its fun- 
 damental properties, as often, most demonstrably, in its origin, is 
 an intermittent. And while I hope to prove that there also is a 
 common modification of this disease, even as an original one, too 
 slight and undecided in its form and recurrence to attract the at- 
 tention of patients as a fixed and serious disorder, far less that of 
 physicians, and while also I believe that the latter have most cul- 
 pably overlooked or mistaken its nature, it is this common disor- 
 der which I believe to be the chief source of the very marked, 
 and also very common suffering produced by the east wind. In 
 plain language, its effect is to produce a fit of ague, or a continu- 
 ance of that vexatious disease : and, in a thousand instances, 
 when it is not at all suspected, and where also, very often, the 
 patient is accused of hypochondriasis, nervous feelings, or feeble- 
 ness of mind. 
 
 Were I inclined to extend these remarks further, to the whole 
 of the popular fancies respecting the east wind, this would not be 
 a fit place for the inquiry ; nor do I feel any desire to enter the 
 lists further against common opinions, sensible that I have al- 
 ready brought a host to the encounter. 
 
 Yet if the east wind is equally pernicious all over the world, 
 as is the popular theory, and as is even seriously asserted by phi- 
 losophers, even to the very words, let it be explained, first, what 
 is the common principle which unites all east winds, and which 
 can possibly act on the body as a common cause, when it is so 
 easily proved that, independently of any supposed Malaria con- 
 tained in it, all its obvious conditions, heat, cold, moisture, dry- 
 ness, are every where variable, and every where different. It is 
 not any mystery or charm comprised in the term east that can act 
 on the human body. And in matters of fact, is the east wind that 
 traverses frozen Siberia the same east wind that sweeps the burn- 
 ing sands of Africa, or is this latter the east wind loaded with the 
 produce of American swamps ? Is the trade wind of the wide 
 ocean the east wind of March in Lincolnshire ? is it not, on the 
 contrary, as innoxious as the west winds of the Atlantic in En- 
 gland ? It is the very salutary breeze itself of the burning islands 
 of Western America. 
 
 In many parts of the continent of Europe, in France, in Ger- 
 many, in Poland, in Russia, the east wind is often perfectly inof- 
 fensive ; it is neither spoken of nor thought of, and for reasons not 
 generally difficult to assign. If in the latter, Petersburgh is a 
 noted exception, there must be causes, and very probably consist- 
 ing of some peculiar direction in the course of the wind, which 
 have not been investigated. In Sardinia again, its effects are such 
 
154 PROPAGATION OF MALARTA. 
 
 as to render that side of the island which is exposed to it a desert, 
 while a vigorous vegetation flourishes beyond the range of moun- 
 tains which divides this country : and thus also, in Minorca, it will 
 not sutfer an orange tree to protrude a leaf beyond the shelter of 
 a garden wall. These, and hundreds of similar occurrences, con- 
 firm the fact that its effects, on vegetation as on animals, depend 
 on the ground which it has traversed, and very materially on 
 what it has crossed last: on its acquired qualities as compared to 
 the west wind, or else on its comparative force. If, in one coun- 
 try or on one coast, it is the east wind that burns and checks ve- 
 getation, on another it is the west ; and thus, even in our own 
 island, to select two purely local and limited examples only, out 
 of far more, it is before the east wind that Mount Edgecumbe 
 roots its splendid trees even in the sea, not daring to show a leaf 
 to the western ones ; while in Southampton river, it is precisely 
 the reverse, and while the contrast produced by the proximity of 
 a vigorous and a stunted vegetation, on immediately opposed 
 shores, is here most striking. 
 
 The popular philosophy requires to be reviewed, and not only 
 so, but to be abandoned. The east wind may be poisonous where 
 it carries Malaria ; it is a cruel and bitter wintry wind across Si- 
 beria, and it is raw and harsh as it travels a land of cold swamps 
 or a frozen ocean ; while it is burning and dry in the Sahara, and 
 even in our own English July. This is the east wind ; it has bad 
 properties when it blows under evil circumstances ; and the worst 
 of all these, as it is the apparent cause of its ill reputation is, that, 
 to us, and to others also, it is the best vehicle of the ague. 
 
( 155) 
 
 CHAPTER VIII. 
 
 On the seasons and climates peculiarly favourable to the produc- 
 tion and propagation, or to the effects of Malaria. 
 
 As it is a well known fact that remittent and intermittent fevers 
 are more or less severe in different climates, and in different sea- 
 sons in any one country, it must be concluded that the production 
 of Malaria is modified by differences of temperature, or else that 
 its effect in producing those diseases is thus modified. Either of 
 these two may be the truth ; or else the result may be compound- 
 ed of both ; so that in this case, unfortunately, as in many others 
 in physic, among conflicting circumstances, we cannot always 
 hope to discover exactly what the fact is. And as we can judge 
 but by the effects, it is not safe to speak, except with some reser- 
 vations, as to the effect of season, or heat, in the production of 
 Malaria. The effect of heat on the body, simply as such, is sup- 
 posed to be to produce disease, or a disposition to disease : and 
 that of long continued heat is thought to be to affect the biliary 
 system in some manner, so as to excite an increased or a morbid 
 secretion, the source, among other things, of cholera. Hence we 
 can conceive that if Malaria is applied to a system thus prepared 
 for disease, the result may be fever, or dysentery, and that the ef- 
 fects may be severe in proportion to the previous preparation or 
 susceptibility. Thus, that extent and severity of disease which 
 might seem the consequence of an increased or unusual quantity 
 and virulence of Malaria, may depend on nothing more than the 
 unusual condition, both in numbers and susceptibility, of the sub- 
 jects to which it is applied. 
 
 But, on the other hand, since it is ascertained that a certain 
 state of vegetation or vegetable decomposition is the source of 
 Malaria, and that this process requires heat and is suspended by 
 cold, we are entitled to argue that as heat does produce, in its 
 gradual increase, a corresponding rapidity or profusion of vegeta- 
 ble growth and decomposition, so ought it to generate a corres- 
 ponding proportion of Malaria, proportional also, it must be sup- 
 posed, in activity. But further, while it remains to be proved 
 that the influence described in the foregoing paragraph is a real 
 and efficient one in this case, I may continue to remark that the 
 effect of cold is to produce, like that of heat, a predisposition to 
 diseases; but of a far different nature, since that consists in active 
 inflammations. This is the predisposition of spring; as biliary 
 
156 EFFECTS OF CLIMATE AND SEASON 
 
 disease is that of autumn, or is supposed to be so. The cold of 
 winter cannot therefore be esteemed a predisposing cause for the 
 fevers of Malaria which occur in spring, though it may so modify 
 the action of the poison as to cause it to produce what it does 
 generate ; simple intermittent, and not bilious or common remit- 
 tent. Or, the variations of the temperature of spring can have 
 no effect, as modes of heat, in predisposing to any modification of 
 fever; so that whatever diversities then take place in the quality 
 of the disease, must be the result of differences in the poison it- 
 self. And therefore, if the fever of Malaria is, in any one spring, 
 more abundant and severe than in another, it is probable that the 
 cause consists in a varying generation of that substance ; in a dif- 
 ference in quantity, duration, extent, or activity. 
 
 And the same analogy may consequently be extended to the fe- 
 ver of autumn. There is actually more of the poison produced ; 
 and the quality of that may be worse, because vegetation and de- 
 composition are more active. There are other phenomena also, 
 noticed, partly in this essay, partly in the medical portion of this 
 work, which prove, that, abstractly from all effect of climate, 
 the severity or quality of the resulting diseases is proportioned to 
 what we must consider the production of Malaria. Of these, is 
 the case of sugar ships, that of hemp, and that of certain fortified 
 places, such as Havre ; and of such is the case of the Pontine 
 marshes, of Bresse, or of Forez. In some of these, the climate 
 and its effects must pass for nothing ; because the peculiarly severe 
 consequences occur at all times alike ; early in the year, or late ; 
 or at sea, where the climate cannot be reckoned ; while in the 
 others, and in a thousand similar cases in France and Italy, the 
 climate and its effects are the same to the inhabitants over con- 
 siderable tracts of country, but the peculiar severity and character 
 of disease, single or epidemic, are confined to chosen spots, and 
 those spots the very ones which we should judge, from their very 
 characters, suited to produce an especially abundant or virulent 
 Malaria. 
 
 I might easily extend this class of proofs ; all leading to the 
 inference that variations of the poison produce variations of the 
 consequent fevers; while nothing can be stronger in this view, ' 
 than those cases where the epidemic has been the consequence " 
 of propagation rather than production ; the result of peculiar 
 winds, or of the removal of trees; and where, the climate con- 
 tinuing the same, the results have differed, and, as is the fact, 
 most seriously. It is therefore proved that every change of char- 
 acter, or every effect as to fever, epidemic or otherwise, is or 
 may be independant of predisposition ; while I know not that 
 there is a single fact to prove the reverse. If there has been a 
 hot season, or a moist one, which might be supposed a predis- 
 
AS TO MALARIA, 157 
 
 posing cause, we know that either of these alters the production 
 of Malaria ; but it has never been proved that such events affect 
 the body as predisposing causes, far less as the real causes of such 
 fevers. It is so assumed by the physicians ; and therefore, as is 
 usual in physic, it is supposed to be proved, and becomes a dog- 
 ma. But even granting this to be true to a certain extent, it must 
 be considered a fact established, that the variations in fevers or 
 periods of fevers, depend principally, or entirely, on variations 
 of season as regulating the production of Malaria ; while we do 
 not require another cause, if this is adequate to all the effects. 
 
 Whatever may be the influence of heat on the body in modify- 
 ing the characters of these disorders, it is an inquiry for the me- 
 dical part of this work, and I may therefore proceed to observe, 
 that as this is a question of temperature chiefly, it applies equally 
 to climate and to season ; and consequently, that an unusually hot 
 season will, in our own country or in any other, be attended by 
 an increase of Malaria, just as this poison is most destructive in 
 the hottest climates ; while it is amply confirmed by observation, 
 that the precedence of a very hot summer is always followed, in 
 autumn, and in every country, by an increase of the diseases pro- 
 duced by Malaria. Nor is it less familiar that intermittent is more 
 prevalent in some years than in others ; while there occur also 
 sequences of years in which it abounds, to subside again for other 
 similar intervals ; these effects being independent of that increase 
 or diminution which arises from changes in the soils of a given 
 country, whether these have been meliorated by drainage, or de- 
 teriorated from opposite causes. 
 
 Now, while it is in spring especially that intermittents are pro- 
 duced, as the remittent is the produce of autumn chiefly, there 
 are no observations of any value, whence we can deduce the 
 nature of the present or previous season in which intermittent 
 fever abounds in an unusual degree, however we may explain 
 this fact as to remittents. 1 allude here to the production, not to 
 the transportation, of Malaria, because this latter cause of the 
 diseases arising from this poison must always be local ; as it is, 
 for example, with respect to London, for the reasons assigned in 
 the last chapter. Thus, although our seasons of intermittent are 
 always seasons of east wind, this is a partial consequence; since, 
 from analagous causes, the unhealthy season of Flanders is a sea- 
 son of southerly winds. 
 
 The observations of Sydenham and others are of no value on 
 i this point ; but it may be conjectured that a mild winter, in which 
 i vegetation is not absolutely checked, ought to be succeeded by 
 j an unusual produce of this poison, and of intermittent ; while the 
 j same results will probably follow from the sudden accession of a 
 hot spring, attended by, or following, much moisture, and excit- 
 
 W * 
 
158 EFFECTS OF CLIMATE AND SEASON 
 
 ing an active and rapid vegetation. But be the particular actions 
 what they may, it rarely happens in our own country, nor gene- 
 rally throughout Europe, where simple or original intermittent 
 prevails, that it is produced in the quotidian or tertian forms at 
 least, and as a new disease in a healthy subject, before the month 
 of March, nor after the end of May ; while this also is the period 
 in which it is most easily re-excited in those with whom it is a 
 habit, and in whom it may have become for a time dormant. 
 That quartans are often produced in autumn, is one of those un- 
 explained circumstances belonging to these singular disorders 
 which here forms a species of exception. 
 
 With respect to remittents as connected with season, the 
 grounds of judgment are somewhat different in appearance, though 
 the principles are the same. Yet 1 must compress a part of the 
 subject which in itself has occupied volumes. When, in one hand 
 alone, the mere Malaria of Italy fills four large ones, to say noth- 
 ing of a hundred other works, he who has but one for every thing, 
 must be excused the brevity to which, on any particular subject, 
 he is condemned. 
 
 The heat of a season or climate being admitted as the funda- 
 mental circumstance in producing and regulating the production 
 of Malaria, it must be expected that, in any given country, fevers 
 will be most numerous and severe as the summer heat has been 
 most considerable and most long continued. But with this also, 
 other circumstances combine to determine peculiar effects ; and 
 of these, one of the most common is, an autumnal season of rain 
 following upon long-continued heat, the same state of things pre- 
 ceding it, or even the occurrence of alternations of rain with heat, 
 or strong and sudden contrasts of heat with cold ; the former cau- 
 ses appearing to act solely on the production of the Malaria, 
 while the last may possibly act as a secondary cause on the body 
 itself, or on the people. It has also been observed, and too often 
 to admit of any doubt as to the truth of the remark, that if an en- 
 tire rainy summer has been succeeded by a hot one, that summer 
 is a peculiarly unhealthy one, or becomes an epidemic season ; 
 the effect being similar to what happens from a rainy autumn suc- 
 ceeding a hot summer. And the solution of all these cases is 
 sufficiently obvious ; while it is easy also to see the analogy which 
 they bear to the case of Africa, or of the tropical climates subject- 
 ed to distinct seasons of rain, as formerly explained. 
 
 Such being the circumstances, a country like ours, which is 
 but partially subject to fevers, may suffer to a greater extent, or 
 disease may be produced where it had not formerly appeared ; or 
 else, in certain parts, that slight endemic by which, for example, 
 Lincolnshire or Essex is characterized may become an epidemic, 
 and to us, a severe one, if slender as compared to Italy or France, 
 
AS TO MALARIA. 159 
 
 And such has been the fact very generally in this present year ; 
 numerous villages in Lincolnshire, Essex, Sussex, Kent, and in- 
 deed almost everywhere, in which the autumn used formerly to 
 pass over with a few insulated cases of fever, having been ravag- 
 ed by epidemics which might well compare with those of many 
 parts of France and Italy. And in the same manner, those fe- 
 vers have appeared where they were formerly unknown, and 
 even their possibility unsuspected ; a fact which, in many places, 
 seems to have excited considerable surprise, especially among 
 those who had resorted to them as formerly, to seek for health. 
 That all these have been cases of marsh fever, and not of typhus, 
 as commonly supposed, is incontestable ; while, proving that 
 England is really exposed to Malaria very widely, an examina- 
 tion of these places so as to ascertain the exact cause, might be- 
 come useful to those who are as yet ignorant of the nature of per- 
 nicious soils ; as it might also convince the incredulous, of the 
 hazards arising from a rivulet, a meadow, a horse pond, a trim 
 canal, a coppice, or a gravel pit. 
 
 Thus also while, in ordinary seasons, such diseases are never want- 
 ing in the countries peculiarly subject to Malaria, constituting the 
 endemic fevers of theirinsalubrious districts, that endemic becomes 
 an epidemic in such peculiar cases ; forming those noted periods 
 of mortality, of which so many have been recorded by authors, 
 in various countries, both in ancient and modern times. I could 
 not here pretend to enumerate these, numberless as they are ; 
 while, for particular purposes, I have elsewhere been obliged to 
 point out a few cases : but, in as far as our own country is now 
 capable of producing such epidemics, if the present year, 1826, 
 and indeed the two preceding, are examples, as they are proofs of 
 the cause, the state of Middleburgh in the present season, in a far 
 other region, shows how a condition, in all cases sufficiently bad, 
 may be aggravated by the precession and presence of an unusual- 
 ly hot summer. 
 
 On all this let me make one general remark. I have named 
 Sydenham, and I desire to except him, as, in addition to his long 
 established fame, his age was not one in which any great accura- 
 cy on such points could have been expected. But when we look 
 at the medical reports of seasons as connected with the produc- 
 tion of diseases, we find little or nothing but collections of loose 
 observations on winds, temperature, barometrical oscillations, 
 rain, and whatever else, drawn perhaps into some vague parallel 
 with the diseases of the same periods or years, but unclassified, 
 unarranged, and unallotted. There is no reference to the general 
 principles on which these ought, or might be supposed to act ; 
 and if the atmospheric phenomena are confounded in an indiscri- 
 minate mass, so are the diseases* We must work our way as best 
 
160 EFFECTS OF CLIMATE AND SEASON 
 
 we can through inflammations, remittent fevers, contagious dis- 
 eases, and much more, if indeed that can be done at all ; while, 
 had any classification of phenomena, and any distinctions in the 
 characters of diseases been made, some useful knowledge, or 
 something or other of fact might possibly have been acquired, 
 whereas the whole is now an useless chaos. Tt is the random che- 
 mist who mixes every substance or test which he possesses, with 
 the body to be examined, imagines that he has performed wonder- 
 ful things, and leaves us, out of fifty idle experiments, to discover 
 for ourselves, as we best can, what it is which bears 'on the ques- 
 tion. Let us hope that some system, some accuracy of arrange- 
 ment as well as of observation, will in time be adopted, and we 
 may then expect to see whether at last any valuable information 
 as to disease will be derived from these statistical records. 
 
 But other circumstances besides mere heat, or moisture, or va- 
 cillations of temperature, are often concerned in such cases ; con- 
 spiring often with them, so as to produce epidemic seasons of pe- 
 culiar severity, or otherwise modifying their effects in various 
 ways. Respecting what belongs to the actual production or the 
 propagation of Malaria, these particulars have been noticed in the 
 former chapters ; while it will suffice here, barely to remind the 
 reader of them, in pointing out such facts as the long prevalence 
 of an east wind in England, of a south-west in Flanders, and of a 
 Sirocco in various parts of Italy ; casual changes of the state of 
 the soil, from inundations, earthquakes, breaches of the sea, or 
 whatever else, and artificial operations of an analogous nature ; 
 to omit other collateral agencies which it would be superfluous 
 to name again. 
 
 Besides these, a very few remarks of another nature will be 
 sufficient as to what remains. Among such causes, a bad harvest, 
 implying deficiency of food, or famine, is one, of no small note ; 
 the mode in which it acts being sufficiently obvious. Political 
 circumstances acting on the minds of the people, is another, the 
 destructive influence of which in many instances, can be traced 
 in history : and where, as in the case of war under peculiar cir- 
 cumstances, these causes are united, often including also other 
 evil influences too obvious to require mention, acting on the minds 
 and bodies both, of the people, the consequences have been con- 
 spicuous in every age and country. To say through what details 
 a country which is the seat of war is thus afflicted, or in what 
 peculiar modes the armies themselves are exposed to causes ag- 
 gravating the power of Malaria, would be to describe what a mo- 
 ment's consideration will suggest to every one. 
 
 As examples of such epidemic seasons, I may name the year 
 1691 in Holland; the pestilence, as it may be called, having been 
 generated by the unusual heat of the summer, or by a more effec- 
 
AS TO MALARIA. 161 
 
 tual vegetable decomposition : a case parallel, though in a far 
 higher degree, to that of the present year 1826, already noticed. 
 At Venice, 1535 was a remarkable season of epidemics, compa- 
 ratively healthy as that city is, when its situation is considered ; 
 and such was the case at Copenhagen in 1652: the immediate 
 cause, in both instances, having been the exposure and drying of 
 land and mud which had generally been submerged. In 1707, 
 Bagnaria in Tuscany experienced the same fate from the drying 
 up of the canals ; and according to Lanzoni, the great epidemic 
 of Ferrara in 1728, was the produce of unusual autumnal rains 
 in the preceding year, .followed by a hot summer. In Normandy, 
 at Bernieres, an unusual course of south-west winds, blowing 
 across the marshes and conspiring with a hot summer, caused the 
 epidemics of 1809 and 1811 : and, to cut short these examples, I 
 may conclude by simply naming the noted epidemic of Naples in 
 1806, prevailing chiefly at Ercola, that of Narbonnein 1801, and 
 that of Pethivier in 1 802, arising from different causes of the same 
 nature. Of epidemic seasons following war, history, both ancient 
 and modern, is full ; and I may barely remind my readers of them ; 
 while the explanations now furnished will render those facts more 
 interesting than they probably had been on a cursory view. 
 
 Some of the former considerations will explain the cases of 
 noted epidemics when the character consists merely in an aggra- 
 vation of the simple fever, and in a wider influence : but, when, 
 in such cases, the character of the epidemic is also peculiar, other 
 collateral causes will be found to have acted. But not to enter 
 into superfluous details, it will be apparent to medical readers, 
 how a previously cold season followed by a hot one, may modify 
 such fevers to an inflammatory tendency, and how similar effects 
 may take place from the occurrence of cold winds or rains during 
 such a season, or in the midst of such an epidemic state of dis- 
 ease. Hence, and from other causes, some of which are familiar, 
 while others are still obscure, the characters of such epidemics 
 vary in different seasons and in different places ; while, barely to 
 enumerate such recorded varieties, would not only be a tedious 
 task, but is one which belongs rather to the proper history of the 
 diseases themselves, than to the subject in hand, or to the history 
 of Malaria. 
 
 If I have noticed the general period of commencement for in- 
 termittent among ourselves, I may also now point out what re- 
 lates to that of remittent or summer fever. The beginning of this 
 may generally be dated from the middle or end of August, rarely 
 as early as the end of July ; while it may be esteemed to termi- 
 nate, as far as new attacks are concerned, before the middle or 
 end of October. Thus the two months of middle summer and 
 the four of middle winter are not only the freest from original at- 
 
162 EFFECTS OF CLIMATE AND SEASON 
 
 tack9 of the diseases of Malaria, but may, in this respect, be 
 esteemed the healthiest portions of the year, this being further 
 true, of the summer period, for all diseases. 
 
 All this however must be taken with great exceptions for par- 
 ticular seasons and particular situations. Thus, in the present 
 summer, 1826, remittent has appeared as early as the end of 
 June ; while in some extensive, and at the same time unhealthy, 
 districts, such as Essex, for example, not only has it been severe, 
 but has in some summers, and even very recently, commenced 
 with the spring or the beginning of summer, as it does in parts of 
 Italy, so as to occupy what, with us, is usually a period of mere 
 intermittents, and thus to extend even to the end of autumn. And 
 thus also if, in the present and the late hot summers, it has been un- 
 usually early as well as epidemic in some particular spots, it will 
 always be found that in those, and in every season, its commence- 
 ment is earlier, and its duration longer, than in others where the 
 causes productive of Malaria are less conspicuous or extensive. 
 And it is not less remarkable, that in the present season, many 
 severe and original cases occurred as late as November, and even 
 later, in particular spots : an event which is rare, even in the more 
 insalubrious parts of France and Italy. 
 
 Other countries, as might be expected, are under the rule of 
 periods somewhat different; while if, in these, the season of Ma- 
 laria is generally of longer duration, in proportion to the heat of 
 the climate, it sometimes also happens, as it does in the rare cases 
 just noticed in our own, that the vernal period of disease, or that 
 which may be considered the proper season of intermittents, 
 which, however, as vernal disorders, are comparatively rare in 
 those climates, runs into the autumnal or remittent season, so as 
 to leave no portion of the whole summer, even from March to 
 November, free ; a fact which has occurred repeatedly in some 
 of the peculiarly insalubrious districts of France. In Italy, as a 
 general rule, the Malaria prevails from the solstice to the equinox ; 
 but it very often also appears as early as May, while in the Pon- 
 tine marshes, it continues even to the end of October, or later; 
 the effects being augmented by the rains of September and Octo- 
 ber. The same varying rules may be applied to France and Hol- 
 land : but it is unnecessary to protract this detail as to the seve- 
 ral countries of the world ; since a mere knowledge of any speci- 
 fic climate and country is commonly sufficient as a ground of 
 judgment, because the same general rules govern all places. 
 
 1 may as well however notice one supposed fact here, in addi- 
 tion, since I could not find a much more appropriate place for it. 
 This is the influence of the moon, real or imaginary, in the pro- 
 duction of Malaria, or of fevers ; since it does not seem to be 
 well ascertained which is the real fact. The evidences to be 
 
AS TO MALARIA. 163 
 
 found in Jackson, Lind, and Balfour, but chiefly in the latter, 
 seem difficult to doubt ; while if the effects depend on the increas- 
 ed production of Malaria, in the oriental regions where this cir- 
 cumstance particularly occurs, it has been explained by the higher 
 state of the tides at the new and full moons, and by the conse- 
 quent and subsequent exposure of a larger space of wet mud. 
 But 1 must refer to those authors for such proofs and details as 
 "would here exceed the space which I can allow for facts of a 
 doubtful nature and for disputed opinions. 
 
 I must pass to the subject of mere climate ; on which, if a 
 volume might be written from the works of others, it would be a 
 volume of little value, as a few simple principles will include all 
 which the subject contains, of any interest. 
 
 The basis of the whole question is indeed comprised in the few 
 leading facts which have been already laid down ; while season 
 and climate are, in reality, as to this subject, almost interchange- 
 able terms : so that by referring to them, it will always (with 
 some yet unexplained exceptions) be easy to determine why any 
 specific climate is productive of Malaria and its diseases, and also 
 a priori, whether it is so or not. 
 
 Marshy or swampy land, or a vegetation and subsequent de- 
 composition taking place in a soil alternately wet and dry, or in- 
 termediate between moisture and dryness, is, as has been fully 
 shown, the general or most common basis of the whole evil, if it 
 is not the sole and exclusive source of the diseases in question : 
 and it is indifferent under what precise circumstances or forms of 
 soil and site this essential fact exists ; as the space or extent seems 
 equally indifferent, further than as relates to the extent or range 
 of the evil. 
 
 The next essential circumstance is, an active vegetation follow- 
 ed by a rapid decomposition ; and as this is always proportioned 
 to the temperature, directly, moisture being presumed to be ne- 
 cessarily present, it is thence easy to compute, with sufficient pre- 
 cision for this view, where we are to expect Malaria and its dis- 
 eases. Hence the latitude alone proves nothing; since, in ele- 
 vated intertropical situations, the tendency of vegetable death is, 
 as in cold climates, to produce peat, as I formerly showed, ra- 
 ther than to fall into that more perfect decomposition which 
 | seems necessary to the generation of Malaria. 
 
 1 ought here also to notice one specific fact appertaining espe- 
 cially to the tropical climates, which is a very principal cause of 
 their insalubrity, or of their power in producing fevers ; though it 
 necessarily has already come under review as connected with the 
 state of the soil, and therefore requires mention now, merely for 
 the sake of order. This is that peculiar division of seasons which 
 is marked by a decided interval of rain associated to one of entire 
 
164 EFFECTS OF CLIMATE AND SEASON 
 
 dryness : the monsoon oflndia, the rainy season of Western Africa, 
 How this acts, I need not repeat : but let it happen where it may, 
 it will always indicate an unhealthy region, on which we may 
 calculate without fear of error. And in as far as it is a question 
 of season as to such climates, it is one on which there is no igno- 
 rance, at least among the natives of such countries: if war and 
 colonization have not always conducted themselves under such 
 circumstances, with all the prudence and all the appearance of 
 knowledge that might have been wished. 
 
 If, in intertropical climates, a moist atmosphere, or that hot 
 fog, if I may use such a term, so noted in some parts of Africa, is 
 peculiarly favourable to the production of the diseases of Malaria, 
 the cause may partly consist in the greater activity, both of vege- 
 tation and decomposition, partly . in a conducting, or perhaps a 
 chemical power in such an atmosphere, peculiarly suited to the 
 action of the poison, or in a greater facility of propagation ; and 
 partly also, it is possible, in the pernicious influence which such 
 an atmosphere exerts on the body : rendering it susceptible 
 of this poison, or ill fitted to resist it, or else prepared to suffer 
 seriously from the diseases which it produces. 
 
 It is not easy to avoid making a remark here, in which human- 
 ity at least is concerned, and in which it is difficult to conceive 
 that justice and sound policy do not unite with humanity ; though 
 for a remark of this nature in such a work, I must both apologize, 
 and submit to such criticism as may accrue. As a question of 
 state policy, I am fully aware of the difficulties and the objec- 
 tions ; and not unaware also what side, under a sentimental phi- 
 lanthropy, certain advocates of humanity are likely to^take. 
 
 To men of ordinary reasoning powers and plain sense, (being 
 those from whom I have borrowed this remark,) it appears extra- 
 ordinary that our tropical African colonization should be carried 
 on by innocent and honest subjects, while the finest and healthiest 
 climates in our possession are set apart for the guilty, and allot- 
 ted as the means of punishment. If it be true, as is asserted, that 
 for every negro gained to our new African civilization, an Euro- 
 pean life is paid, the purchase is made on terms sufficiently se- 
 vere ; but putting this out of the question, the naval officers who 
 have been employed in this service, cannot see without regret, 
 the loss of valuable men which has arisen from the business of 
 cutting wood on these pestiferous shores, while reflecting also 
 that such work might be performed by men of a far different va- 
 lue, and who have forfeited their lives to the community. Needs 
 it be said that hundreds of efficient seamen, or of innocent men, 
 have been sacrificed on duties which, even to their own convic- 
 tion, almost imply a sentence of death, and on duties that might 
 be performed by persons of infinitely less value to society, of 
 
AS TO MALARIA. 165 
 
 even far less pecuniary value to the state ; as they might be by 
 men on whom society and the state alike hold claims, in return 
 for the indulgence which they have received from justice. 
 
 It is not easy to see what reasonable blame could attach to our 
 criminal law, if the forfeit of life were commuted in to a sentence 
 of labour on the African coast, instead of transportation to New 
 Holland, at least in specific cases; and if the duties in question 
 must be executed, there can surely be no hesitation respecting 
 the comparative justice, any more than the humanity, as these 
 are now carried on ; since it is in vain to say, as has been said, 
 that a seaman is a free agent in this case, when he cannot decline 
 obedience to his orders, though orders of peace and not of war. 
 Though he has entered freely, and has calculated on many labours 
 and hazards, he has not calculated on sickness and fevers beyond 
 the ordinary average of human events ; nor foreseen that it would 
 be his lot to labour in African swamps with an inglorious death 
 before his eyes, too often to lose his life for a cask of water or a 
 bundle of wood. 
 
 Yet thus much, forming the ordinary service of ships, is per- 
 haps unavoidable ; and must be endured. But the cutting of 
 wood for other service than the immediate wants of the ship, is not 
 in the course of duty -and the question is, whether it should be allot- 
 ted to innocent and valuable men, either in a view of economy or of 
 humanity. It is not my opinion however, but it is that of the 
 officers whom I quote, that this is a duty which might be per- 
 formed by convicts, easily and advantageously. That there is a 
 modern philanthropy which would raise its voice against such an 
 attempt, is probable : yet the work must be executed by some 
 one ; and the naval commander who feels that he is condemning 
 to death those who have accompanied him before the dangers of 
 the sea and the enemy, by the order which commands a boat on 
 shore to cut timber in an African swamp, will not be convinced 
 that the present policy is either humane, or just, or expedient; 
 however unable an individual may be to offer the remonstrances 
 which some of the most respected of this class have here request- 
 ed me to make for them. 
 
 Further, and to proceed to our proper subjects, there may be 
 many local causes in such, as in all climates, capable of aggrava- 
 ting or determining the action of this poison ; such as a confined 
 valley unfavourable to ventilation, or woods similarly concen- 
 trating its action, or forms in the land, or winds of a peculiar 
 direction, fitted to carry its energies to some given point ; cir- 
 cumstances which have been fully detailed in the last chapter, 
 and which it now can only be necessary to allude to in this 
 place. 
 
 But in reality, many of these circumstances are in themselves 
 
66 EFFECTS OF CLIMATE AND SEASON 
 
 eculiarly regulated by climate : or if a warm climate acts in 
 le production of fevers, through its heat, its moisture, and its 
 lore rapid vegetation, so does it by means of the unusual multi- 
 jde and density of its trees, by the peculiar combinations of these 
 rath its rivers or its estuaries, and by other circumstances of a 
 3cal nature, which it cannot be necessary to recal to the minds 
 f those who possess even the slightest geographical knowledge. 
 
 On this subject in general, there is one remark worth making ; 
 lthough, as derived from the doctrine of final causes, it may not 
 t the present day be very generally acceptable. It is one of 
 be apparent laws of nature, that the habitable surface of the earth 
 hould be gradually extended by the action of causes which geo- 
 ogy demonstrates ; while, from the same law, it follows that the 
 lew lands are, in a great ratio, more productive than the old, on 
 i comparison of areas ; with exceptions, of course, for which 
 here is no room, as there is no necessity, in this place. These 
 re the alluvial plains, constituting the most valuable and popu- 
 ous tracts on the surface of the globe : and their enormous 
 extent can be estimated by every geographer, as geology demon- 
 trates their certain and progressive increase. 
 
 It would be abundantly easy for any geologist to point out, 
 >ver the entire world, what new lands have been formed since 
 he mountains first arose out of the waters ; though the compu- 
 ation would surprise those who have never considered this sub- 
 ect : as it would not be very difficult to foretel what is yet to 
 lappen in this respect ; where new lands are to be formed, and 
 where and how the old are to increase, extending the habitable 
 mrface of the globe for future and increasing races of men : and 
 with that also, producing lands a thousand times more fertile than 
 those which Nature first formed, so as to augment, not by simple 
 addition, but in a ratio which may be considered geometrical, 
 the powers of the earth in providing for the, unfortunately, "still 
 more rapid geometrical increase of population. 
 
 Now in the hot climates in particular, from the extraordinary 
 vigour of vegetation, as well as, in some measure, from the moral 
 condition and habits of the people, these tracts are productive of 
 a population, even to excess and incumbrance ; and it is in these 
 very lands, as if for the purpose of a constant check, that there 
 have been implanted the steady and ever-active seeds of disease, 
 operating as a perpetual relief to what would otherwise perhaps 
 find no relief but in the greater misery of famine. If this evil also 
 operates when it is not similarly productive of good, it is no more 
 than happens throughout the whole system of nature, where ge- 
 neral laws have been established for the production of general ef- 
 fects. ^ 
 
 I might now proceed to a detailed statement of the climates in 
 
AS TO MALARIA. 167 
 
 which Malaria and its diseases prevail most conspicuously ; but 
 almost every enlightened reader can here form such an one for 
 himself; and I could but repeat what, perhaps, every one can 
 conjecture. It will be better to leave this subject to the reflec- 
 tions and researches of those who may be interested in it ; while 
 it will be more advantageous to enumerate, as an illustration ra- 
 ther than a history of Malaria in its relations to climate and coun- 
 try, a few examples of what may be called its geography. 
 
 I grieve to say that this must be very imperfect, as much per- 
 haps from want of correct information as from want of space. I 
 have already hinted that there is no work more wanted in medi- 
 cal statistics than a geography of Malaria ; a work which, in Eu- 
 rope at least, seems of pressing urgency, from the 'great increase 
 of travelling, as well as of migrating residents abroad, and from 
 the mass of misery, added also to a considerable mortality, which 
 results from their ignorance, not merely of this necessary geogra- 
 phy, but of the simple fact itself, or of the leading principles by 
 which the production of Malaria and its diseases is regulated. 
 Everywhere in France and in Italy, we may find whole families 
 suffering under diseases which are often incurable, produced by 
 an incautious choice of residence, or returning home with ruined 
 health, from the very lands where they went to seek both health 
 and happiness ; objects of misery and suffering as long as life shall 
 last. 
 
 If there is not much written on this subject, there is however 
 something ; and among what is recorded, I may point out an ex- 
 cellent statistical table of Malaria drawn up by Captain Smyth, 
 for Sicily, extremely valuable if accurate, and apparently ex- 
 tremely accurate. And it is especially valuable because of its de- 
 tails ; since, after all, these are what are required. To be want- 
 ing in these particulars, is the fault of the Italian writers in ge- 
 neral, as it is of the French ; since, from the whole united, we 
 could not derive such a statement as that to which I have just 
 alluded. 
 
( 168) 
 
 CHAPTER IX. 
 
 On the Geography of Malaria. 
 
 It must be plain that to detail the geography of Malaria for the 
 whole world, would be little else than to write a general gram- 
 mar of geography ; and that to do this, even for Europe alone, 
 would be to produce no small work. What the numerous and 
 voluminous writers of Italy have done for their own country mere- 
 ly, on this subject, will prove that 1 do not exaggerate on this 
 matter. My own sketch must necessarily be a very slender, and 
 also a very confined one : and even indeed had I the space to 
 make it larger, I should be unable to procure the requisite infor- 
 mation, since it does not exist. 
 
 Respecting the three great divisions of the globe, there is noth- 
 ing whatever to be discovered beyond the most casual and dis- 
 persed notices, to be found, rather by good fortune than industry, 
 in the writings of travellers : and with regard to Europe indeed, 
 there is the same blank, with the exception of France and Italy : 
 since even Holland has not chosen to inform us on this subject ; 
 deeming perhaps that the whole might be comprised in one word. 
 And though Italian writers abound on the subject of Malaria in 
 all its relations, they seem generally to exhaust themselves in 
 speculations and theories rather than facts ; or, if noticing sites 
 and places, it is to discuss to weariness some spot so notorious as 
 to demand no further illustration, and to neglect those details 
 which are wanted for use, and which alone ought to form the plan 
 of such a work. Thus also have I been disappointed in Monfal- 
 con ; who, appearing as if he had intended to give us the entire 
 geography of French Malaria, has confined himself to a few broad 
 details on some chosen places ; leaving the far greater part of his 
 subject untouched, and, as to any useful purpose, being commonly 
 superficial, or more properly, general, in what he has described. 
 It is impossible to write without materials ; and I, therefore, 
 can pretend but to give some very scattered notices on this sub- 
 ject, in which, moreover, I must almost limit myself to 4 Europe. 
 I had indeed intended to suppress a chapter so extremely deficient 
 and unsatisfactory as this must be : yet when I recollect that 
 whatever I may point out will be a warning to travelers, at least 
 as far as it extends, and when I also reflect, that, by such a de- 
 tail, I may perhaps at length convince our incredulous country- 
 men that there is such a thing as Malaria under blue skies and 
 
GEOGRAPHY OF MALARIA. 169 
 
 amid the perfume of orange flowers, I shall suffer it to take its 
 chance : while it may also, by its imperfection, stimulate others 
 to produce something worthy of the subject. Let me only fur- 
 ther add, in gratitude to a person without whose assistance I could 
 not even have written what I have, that I am indebted to Cap- 
 tain Smyth for nearly the whole of that topographical informa- 
 tion which relates to the shores of the Mediterranean ; while they 
 who may choose to abstract that portion, will see that it forms 
 the greater part of the subsequent details. He is not a physician, 
 it is true : yet if but one physician out of a thousand had observ- 
 ed as well, the entire geography of Malaria would not be now to 
 write, and physic would be relieved from a heavy disgrace which 
 it deservedly endures for this neglect. 
 
 To commence with some general remarks, as they may be ap- 
 plied to those cases or countries where 1 have been unable to spe- 
 cify the exact geographical sites, Malaria may be expected during 
 the warm season, and particularly under the various circum- 
 stances of heat and moisture formerly discussed, in every coun- 
 try in which the mean annual temperature is 45, or even less, 
 much more certainly when that reaches to 50, and most indubit- 
 ably when it exceeds that, in all such places or tracts as the fol- 
 lowing. 
 
 In the warmer climates in particular, yet in all climates under 
 exceptions or modifications, unnecessary perhaps to detail after 
 what has been said, and which would be tedious, at any rate, to 
 specify, it will be the produce of the great alluvial districts which 
 attend the large rivers of the world, such as the Oroonoko, the 
 Euphrates, the Ganges, the Danube, the Congo, and so forth ; 
 and in those cases therefore, it will occupy an extent which is 
 easily assigned by a geographical eye, even on a well constructed 
 map. This will be one leading guide as to a judgment respect- 
 ing such places or tracts of land as I have not here specified, even 
 in the countries which I have noticed ; as it will be for those 
 quarters of the world which I have omitted ; but in similar cli- 
 mates or wherever the temperature is sufficient, the same rule 
 will hold good as to the smaller alluvial spaces attending rivers 
 of less moment, or rivers of almost any dimensions ; and such are, 
 in fact, the leading features of those pestiferous tracts which 
 abound on the shores of the Mediterranean. 
 
 Such portions of land, bounding or skirting rivers, to whatever 
 extent, are however most pernicious, whether situated inland, or 
 on the sea shores, when they include marshes, whether fresh or 
 salt, when they are subject to inundation, like the vallies of Co- 
 chinchina, Ava, and Egypt, when they contain wet woods or jun- 
 gles, and above all, elephant and bamboo jungles, or when, on 
 the sea line, protruding far beneath the influence of the tide, they 
 
170 GEOGRAPHY OF 
 
 give birth to mangrove and similar forests alternately occupied 
 and deserted by the sea. 
 
 This division of physical geography includes, in reality, the far 
 larger portion, all over the world, of that local geography which 
 is most noted for its pernicious qualities ; while exceptions will 
 be found in such open plains as many of those in South America ; 
 where, independently of a form of land less subject to a pernici- 
 ous moisture, or in which that is in a great measure exhausted by 
 a peculiar vegetation, open, if luxuriant, and free of those close 
 and thick woods which are so favourable to the production of 
 this poison, there is not that peculiar alternation of rain with 
 heat, which, in Africa and Asia, appear to be no less aiding in 
 the same effect. 
 
 Next to this particular division of physical geography, I may 
 name those places or wide vallies, abounding in many parts of 
 the world, and very conspicuous in France, where large rivers 
 do not exist, however alluvial they may often be, but where, from 
 an imperfect drainage, water accumulates, so as to give rise, as 
 in Hungary, in the Lyonnais, and elsewhere, to collections of 
 lakes or pools, or to marshy and meadow land, or to wet woods. 
 
 As the margins of lakes are sources of Malaria, the existence of 
 such accumulations of water, constitutes another department of 
 natural geography which takes no small share in this subject ; 
 while it is plain that the essential reasoning is the same as that 
 which is applied to sea shores. Of such pestiferous tracts, the 
 Italian lakes and those of America furnish noted examples on all 
 scales ; while respecting the whole, it will be, in general, suffici- 
 ent for any one to examine a good map, to deduce those conclu- 
 sions which 1 could not here specify without occupying much 
 more space than would be convenient. 
 
 Such are the leading divisions in physical geography which may 
 form our guides as to this judgment ; and any one who is ac- 
 quainted with that great department of natural history, little at- 
 tended to except by geologists and geographers, would find but 
 little difficulty in constructing for himself a map of the Malaria of 
 the world, as far as its natural geography is known. What else 
 belongs to this subject in a general view, is commonly too partial 
 or accidental to admit of a place under this head ; nor need I now 
 repeat all the modifications of land which, incapable of being 
 thus classified, are sources of Malaria ; since the rules respecting 
 these have been sufficiently indicated in a former chapter. 
 
 But if I have mentioned a map of Malaria, I know of few sta- 
 tistical works which would now be more useful than such a one 
 for the world at large ; as far at least as the civilized, and com- 
 mercial or colonizing nations have extended their connections 
 with it : while it indeed forms a branch of statistics and economy 
 
MALARIA. 171 
 
 as to individual countries, which it is disgraceful to the European 
 nations to have so long neglected. It is, in reality, a department 
 in political economy which it is incumbent on every government 
 to investigate and make known ; deeply as it is involved with 
 many of the fundamental principles of state policy, as these relate 
 to the public health and industry, and deeply also as it concerns 
 the great question of war, colonization, and commerce. Execut- 
 ed for Europe alone, it would, as I have more than once suggest- 
 ed, be invaluable to mere travellers ; and I can only regret that 
 my information does not allow me to produce what indeed, even 
 if executed, could not have been appended to a work of this na- 
 ture. Let me only hope that what I here hint may stimulate 
 some of the physicians, who swarm all over Europe as residents 
 and travellers, to commence a task, the neglect of Which is to 
 them in particular, disreputable : and if they wish for an exam- 
 ple, let them follow the road so well marked out by Captain Smyth 
 in his accounts of Sicily and Sardinia. Were there no other 
 proofs of the utility of this knowledge, he would himself furnish 
 an incontrovertible one ; since by this alone he preserved his own 
 health and that of his people during the many years that he was 
 engaged in the survey of the Mediterranean ; occupied incessant- 
 ly in places of the most pestiferous nature, and in every one of 
 them ; as this sketch, in as far as it depends on his communica- 
 tions, will abundantly testify. 
 
 To commence therefore with the sea coasts of Italy, since it is 
 indifferent where 1 begin, if between Nice and Pisa there are oc- 
 casionally interspersed some unhealthy spots, such as, near Vin- 
 timiglia, Oneglia, Albenga, Spezia, and Massa, it is not till we ar- 
 rive at Pisa, or rather at Lucca, that this highly insalubrious re- 
 gion may be said to commence. The whole plain between this 
 city and Leghorn, as far at least as it approaches the sea, is highly 
 pernicious, on the testimony of Italian authors, though it is the 
 region watered by the almost classical Arno : and if Florence 
 does escape that plague to a great degree, it is, on the same evi- 
 dence, far from being the very healthy neighbourhood which it is 
 commonly represented. But it is at Rosignano, or at the mouth 
 of the Cecina, that we must fix the real boundary, in this direction, 
 of one of the most notoriously pestiferous tracts of Italy. Here 
 begins the dreadful and dreaded Maremma of Tuscany ; terminat- 
 ing about Montalto, but continued through the dominions of the 
 church, so as to include the terrific Pontine marshes, as far as 
 Terracina and beyond it. 
 
 Inland, the extent of this region is also considerable; since, at 
 Sienna itself, the annual mortality is one in ten, and even without 
 epidemic fevers, or exclusive of them. It occupies an even wider 
 space within the Roman states; since it surrounds the lake of 
 
172 GEOGRAPHY OF 
 
 Bolsena, and, generally speaking, may be said to reach to the foot 
 of the Apennine ; while the elevated position of Aquapendente 
 and of other towns and villages, demonstrates the conviction long 
 ago felt respecting its insalubrity. There are not many parts of 
 Italy, in fact, more marked by this pestiferous celebrity ; since, 
 from the most ancient times, the Maremma of Rome has been 
 even of worse repute than that of Tuscany ; while the Pontine 
 marshes, I need scarcely repeat, are proverbial ; being almost de- 
 populated, in some parts indeed an absolute desert, and scarcely 
 also to be passed, even in the most rapid manner, in the summer 
 season, without imminent hazard. 
 
 Of Rome itself I need not again speak : and if the town of Na- 
 ples escapes this scourge, it is not so with regard to the sea shore, 
 even from Gaeta ; since many parts are utterly uninhabitable in 
 the summer. Nor is much of the surrounding interior country 
 exempt, in spite of its attractive name Felice : since the aspect 
 of the inhabitants of Mondragone alone, is sufficient to forewarn, 
 if not to terify him who expects that the rich woods and cultiva- 
 tion of the Campagna are a warrant for its salubrity, any more 
 than are the refreshing breezes or the ancient fame of Puzzuoli 
 and Baias. Many of the most highly cultivated and woody parts 
 are in fact the most unwholesome ; and thus Caserta, Agnano, and 
 Cumae may rank with Misenum and Puzzuoli. What Psestum is, 
 on another quarter, even the most incautious travellers now know 
 but too well ; and dearly have many paid for the idle curiosity 
 which prompted them to seek a reputation for taste in exploring 
 its classical ruins. But the whole of this shore from Salerno even 
 to the island of Piana, and far within the land, is alike pestifer- 
 ous ; nor does it cease to be so until the mountains approach the 
 shore far to the southward ; the same plague reappearing at Poli- 
 castro, in the gulf of St Eufemia, at Nicastro and elsewhere ; and . 
 skirting the entire coast from Tropea even to Cape Spartivento 
 and beyond it. 
 
 Hence, along the eastern side of this promontory, the whole 
 Calabrian coast is, if that be possible, even more poisonous ; the 
 seat of fevers of the worst kind, wherever a river exists or a 
 plain is to be found, and escaping only where the high land chan- 
 ces to meet the sea. Thus the whole gulf of Tarento, especially 
 surrounded by wide alluvial plains and giving passage to many; .. 
 rivers, comprises a district scarcely exceeded for unhealthinessT Z 
 by any portion of Italy ; Gravina, at the foot of the hills, hardlyi L7 
 terminating the range of its influence in this direction. Such also* .."■"' 
 is the horrible celebrity of Otranto, Brindisi, and Monopoli, that ; _ 
 it is almost superfluous to name them; but, in fact, this is the ^ 
 character of the whole Adriatic shore here, up to the gulf o : J.' 
 Manfredonia ; while from the bay in particular, the pestiferous J* 
 
 i: 
 
 'IP 
 
she 
 
 MALARIA. 173 
 
 region extends almost to the very foot of the Apennine, so as to 
 include, with that which reaches from the gulf of Taranto on the 
 other side, the largest tract of unhealthy land in the south of 
 Italy. 
 
 Hence to Ancona, the entire coast is but a repetition of the 
 same circumstances ; a hundred rivers flowing down from the 
 mountains, and each forming its little poisonous valley or plain; 
 while the few exceptions that occur, happen where some elevated 
 point on the shore, or a hill in the interior, enables the breeze to 
 divert or blow off that poison which is generated all around. Be- 
 yond this, and even as far as Trieste itself, there is scarcely even 
 this exception along the whole shore; any further than as Venice 
 chooses to claim that exemption which I formerly inquired of. 
 
 But if there are tracts along this division of the shore of Italy 
 more insalubrious than others, 1 need not here separate the 
 mouths of the Po and the Adige, or the notorious gulf of Comac- 
 chio from the interior country to which they belong ; from that 
 extensive plain lying between the Alps and the Apennine, of 
 which so large a portion is noted for its bad air. Here, ten great 
 rivers descend from the Alps, and twelve from the Apennine; 
 joining with four hundred and fifty smaller streams, to propel to- 
 wards the sea that land which they have brought down ; thus ex- 
 tending the shore, and producing marshes and flats or lagunes, 
 such that, in many places, the rivers are almost reticulated by in- 
 osculation; leaving, in consequence, in many tracts, an intermix- 
 ture where the land and water compete for superiority. This is 
 that geological process to which I formerly alluded, by which can 
 be partly explained the great increase of Malaria in Italy in mo- 
 dern times ; and, very particularly, in this division of the country, 
 the palpably accelerating progress of disease, together with the 
 extraordinary difference between the experience of modern times 
 and the reports of the classical ones, as to the salubrity of the 
 coast, even from Catolica to Aquileia. 
 
 If the increased insalubrity of the sea shores on the great plain 
 
 of Italy is accounted for by this increase of those coasts, by this 
 
 immense production of a new territory, every atom almost of 
 
 j which is the parent of a new and extending poison, and of which 
 
 i increase there is abundant evidence in many more ways than the 
 
 long exclusion of Ravenna from the sea, so it is not difficult to ex- 
 
 | plain the similar increase in the interior, dependent on the same 
 
 j causes acting in conjunction with the operations belonging to agri- 
 
 culture. In every similar case of powerful rivers traversing a 
 
 j fertile plain, embankments become necessary, as 1 have formerly 
 
 shown ; and, every year, while the height of these must be in- 
 
 I! ofl! creased, so must they be carried to a higher point on the stream ; 
 0'\ while, the including lands become more difficult to drain, and the 
 
174 GEOGRAPHY OF 
 
 entire region of marshy or wet land is extended, ft is thus, in 
 the district in question, that the Po is now, over a large tract, li- 
 terally running on the summit of a wall, threatening even other 
 dangers than a further increase of that bad health which it is pro- 
 ducing: both circumstances united having led to a design of let- 
 ting it loose to find a new channel for itself, which, had the go- 
 vernment of Italy continued in the same enlightened and power- 
 ful hands long enough, would doubtless have been carried into 
 execution. 
 
 To this cause, over Lombardy, and generally throughout this 
 great plain, must be added the cultivation of rice, or, compared 
 to the classical times, a general change as to the agriculture in 
 general and the growth of woods; comprising details as to indivi- 
 dual spots, for which 1 must refer to Filiasi and others, for want 
 of space to treat such a subject minutely. But I may remark ge- 
 nerally, that wherever, to the north of the Apennine, the same 
 cultivation and the same lands do not produce the same extent 
 of bad health as to the southward of these hills, it must be attri- 
 buted to the effects of the cold north winds from the Alps, and to 
 the screen which the former range affords against the pernicious 
 south winds ; while to the effect of those in a great measure, fur- 
 ther checked and retained also by these mountains, must be main- 
 ly attributed the unusually pestiferous qualities of the Roman 
 Maremma. 
 
 Having premised these explanatory particulars, I may, in a ge- 
 neral way, divide the plain into three parts, namely, from Turin 
 to Milan, from Milan to Mantua, and from the latter city to the 
 sea or the lagunes. This last is the proper marshy district ; and 
 it is almost superfluous to name that tract especially called the 
 Mantuan, since the pestiferous nature of Mantua, Bologna, Fer- 
 rara, and many more places, has been long sufficiently notorious 
 to scare away even those who affect to hold Malaria in contempt 
 If the Milanese is less widely or severely unhealthy, it is still but 
 too well known for the Malaria of its rice grounds ; while all 
 along the Po, even to Pavia and beyond it, and in the course of 
 the Ticino as far as that extremity of the lake of Como, the same 
 insalubrity prevails in the summer season. 
 
 But I dare not give more space to this part of my subject ; 
 which indeed could not be effectually treated, except by such a 
 statistical catalogue of towns as Captain Smyth has produced for 
 Sicily. This must suffice for the pure, the bright, the fragrant, 
 the classical air of Italy, the paradise of Europe ; to such a pest 
 house are its blue skies the canopy, and where its bright suns hold 
 out the promise of life and joy, it is but to inflict misery and death. 
 To him who knows what this land is, the sweetest breeze of sum 
 mer is attended by an unavoidable sense of fear ; and he who, in 
 
MALARIA. 175 
 
 the language of the poets, wooes the balmy zephyr of the even- 
 ing, finds death in its blandishments. 
 
 Such is Malaria. We avoid the infection of the hospital, we 
 may shun the city of the plague, we can shelter ourselves from 
 the pestilence before which thousands are falling around us. But 
 who can hide himself from the universal atmosphere, or refuse to 
 breathe the wide air, though conscious that every inspiration is a 
 draught of poison ? Had nature corrupted the springs and the 
 rivers of a whole country, we might have declined to drink of 
 them, or we at least might have imagined this in our power ; but 
 we cannot refuse to breathe, even when we know that it is the 
 breath of the grave, not the air of life. Fortunately, that which 
 is not seen is forgotten, and fortunately also, habit reconciles us 
 to every thing ; but were the Malaria crimson or blue, and ob- 
 vious to the senses, the poet may inquire what the life of man 
 would be under these circumstances, whether he would not ex- 
 pire from the mere fear of dying, or whether Italy, even Italy, 
 would not, in many parts, be abandoned to its wolves and its 
 mosquitoes. 
 
 With respect to Sicily, I shall here refer to the statistical table 
 of Captain Smyth, already pointed out as a kind of model for the 
 species of travelling guide that I have recommended. The num- 
 ber of situations he has here pointed out as bad, amount to about 
 eighty-two; and, generally, they must be sought along the sea 
 coast, or, as on the Italian shore, where rivers find their exits, 
 forming plains or vallies. I may however point out generally, a 
 few of the most conspicuous ; and among these, Syracuse pre- 
 serves that deadly reputation which it seems to have possessed 
 at all periods. Nothing however can exceed, according to my 
 author, the valley watered by the Abysso, the ancient Helorus, 
 where amidst the splendour and fragrance of the walnut, the 
 olive, the vine, the fig, and the almond, intermixed with jessa- 
 ! mine3, aloes, roses, myrtles, oleanders, and a thousand aromatic 
 ! shrubs, in the very bosom of beauty and luxuriance, amid the de- 
 | lights of a spot which poetry would lose itself in celebrating, the 
 ! miserable and cadaverous natives drag out a wretched existence ; 
 > dying rather than living where the vegetable world spreads all its 
 j colours and odours to summer airs and bright skies. Well has it 
 I been said that Nature hides her poisons beneath her sweets, and 
 i holds out her pleasures to tempt and punish mankind ; when such, 
 | in all these most highly favoured climates and in all the most fer- 
 | tile and the most beautiful spots, is the lot of the human race ; 
 ! here at least guiltless of luxury, and obeying the very dictates of 
 j nature herself in the occupation and cultivation of the soil. 
 . Along the southern shores of this long famed island, not one 
 spot is exempt from the plague of Malaria, even from Catania to 
 
176 GEOGRAPHY OF 
 
 Trapani ; but on the northern coast, the descent of the hills to 
 the sea produces many salubrious situations ; the pernicious ones 
 being thus dispersed, and occurring chiefly near Messina, and 
 thence to Patti, about Cape Orlando, St. Marco, Tassa, Termini, 
 and Castel-a-mare ; with which I shall here terminate this brief 
 notice. 
 
 If Sardinia is even a more notedly pestiferous country than Si- 
 cily, I understand that the officer whom I have just named is 
 about to produce a work on that island also, in which the details 
 of the insalubrious places will be given in the same manner as 
 for Sicily. In the mean time I may remark from him, that the 
 entire eastern shore from St. Pilamo even to the Straits, is but 
 the boundary of a belt of pernicious land which reaches to the 
 foot of the mountains ; while the same also is nearly true of the 
 whole western and southern shores, even from Cagliari to the 
 Cape of Algher. Here, the descent of the mountains to the sea 
 produces a salubrious tract as far as Cape Falcone ; but the pes- 
 tiferous country re-appears within the bay, occupying the whole 
 flat territory about Sassari, and extending far up the country along 
 the course of the Goccomo. Thus, in fact, almost the whole of 
 Sardinia, except in the mountainous tracts, is subject to this 
 plague ; while, whether from peculiarity in the climate, in the 
 relative positions of the mountains and the low lands, or in the 
 effects of the winds, added perhaps also to the habits of the peo- 
 ple, its effects appear to be almost everywhere unusually severe 
 or virulent. 
 
 The entire eastern side of Corsica, from the straits to Bastia, 
 possesses the same characters, though the belt of land is narrow- 
 er; while if Bastia itself is insalubrious, St. Fiorenzo is almost un- 
 inhabitable from the same cause. On the western side, the un- 
 healthy spots are separated by ridges of hilly land, occupying, as 
 usual, the vallies ; and among them, the most conspicuous are 
 the gulfs of Calvi, Porto, Sagone, and Campo Moro, together with 
 that of Ajaccio and the town itself. How severely the French 
 garrisons have at different times suffered in this island, and par- 
 ticularly at St. Fiorenzo, I had formerly occasion to notice. 
 
 From Porto Ferrajo to Porto Longone in Elba, there is also a 
 considerable tract of Malaria : and I had formerly occasion to 
 speak of Minorca as far as it related to Port Mahon, while I may 
 here add the western side of this island about Ciudadela as not 
 less notorious for its insalubrity. In Majorca, the chief pernicious 
 district is that which surrounds Alcudia, extending to a consider- 
 able distance inland; while in Ivica, the unhealthy region in- 
 cludes the town of Ivica itself and the surrounding tract for many 
 miles. 
 
 With respect to Greece, I am compelled to limit myself entire- 
 
MALARIA. 177 
 
 ly to the coasts, and to Captain Smyth's observations, having had 
 little success in my researches among travellers, even when me- 
 dical ones ; there seeming to have been a sort of general agree- 
 ment to neglect this important branch of the natural history of 
 those countries, though the fate of many of our travellers, or of 
 our speculators on Greek liberty, and one noted instance in par- 
 ticular, might have been supposed sufficient to excite an interest 
 in it, even if our occupancy of one portion of this famed land had 
 not. If we commence from Trieste, we may at once condemn 
 the whole flat lands of Istria, from Capo d'Istria to Pola ; where, 
 to travellers, the beauty of the scenery in many places, is ill attain- 
 ed through the hazards which must be encountered, and where, 
 as in Italy, all the dangers from all the banditti that ever lived, 
 are but as a feather against those which scarcely any precaution 
 can guard against in summer. The mountainous coast of Croa- 
 tia seems to be exempt, as is generally true everywhere here, 
 except where some occasional valley of a peculiar character oc- 
 curs : and if among the numerous islands of this shore, there are 
 many not subject to the Malaria, we may be sure that it is where 
 there is no water, as is here frequently the case. But Veglia is 
 not exempt, nor the coast from Nona to Sebenico and Spalatro, 
 nor the islands of Lesina, Corsola, and Melida, and the peninsula 
 of Sarioncello : while nearly the whole of the Dalmatian and Al- 
 banian shores, including the mouths of the Narenta, Ragusa, and 
 Cattaro, and then extending uninterruptedly even to Valona, is 
 one entire tract of fevers, occupying also a very considerable 
 breadth towards the interior country. 
 
 If this pestiferous belt is here interrupted for a space by high 
 land, it recommences at Panormo, extending southwards along 
 the coast, so as, almost everywhere, to surround even the gulf of 
 Lepanto; of variable breadth, and that breadth always regulated, 
 as usual, by the positions of the mountains, or by that form of 
 land to which it is owing that entire Greece is so much less ex- 
 posed to this plague than it would otherwise be. Hence it is, in 
 reality, that the topography of the shores of that country as to 
 this subject, is nearly also the topography of the entire shores, 
 while by pointing out in a few places its inland extent, I shall 
 afford a rule forjudging of others, where, either from ignorance or 
 the desire of brevity, I have not entered more fully into this geo- 
 graphy. 
 
 Thus, while it occupies in part the islands under our own 
 care, namely, Corfu, St. Maura, Cephalonia, and Zante, it ex- 
 tends from the former to Joannina ; surrounding that lake, and 
 reaching down the Arta, so as to include the whole of that gulf 
 also. And thus, further, while it is now but too well known to 
 surround Missolonghi, where, as on manv other parts of this 
 
178 GEOGRAPHY OP 
 
 coast, the immediate shore is marshy, the whole plain or low 
 country including the courses of the Aspropotamo and the Fidari, 
 is a land of Malaria and fevers. 
 
 With the name of Missolonghi just dropping from my pen, I 
 cannot well avoid making a remark on the fate of our great poet: 
 a remark which refers to what I have more than once had occa- 
 sion to point out in the course of this work, namely, the ignorance, 
 or error, respectiug the fevers of Malaria which is so prevalent, 
 and the consequent maltreatment to which they are so often sub- 
 ject. And in using these terms, I do not merely allude to that 
 error so nearly universal among ourselves at home, which does 
 not perceive the situations productive of Malaria, which attri- 
 butes our summer fevers to imaginary causes, or which, still more 
 censurably, mistakes them for typhus, but which, far too often, 
 confounds peculiar modifications of it with disorders of an entire- 
 ly dissimilar character, or overlooks it altogether when slight ; 
 such errors being productive of corresponding erroneous treat- 
 ment or neglect, often attended by fatal consequences. If no fur- 
 ther acquainted with the latter history of Lord Byron than the 
 public is, there seems ground enough for judgment ; while the 
 similar fate of others in the same country and circumstances, and 
 from the same errors, confirms the opinion which 1 felt compell- 
 ed to adopt, from the first moment, respecting the death of this 
 ill-fated personage. 
 
 Had an English, untravelled, practitioner committed this, not 
 merely error, but series of errors, it would have excited no sur- 
 prise, since that occurs in our own country every day : but that 
 an Italian physician should not have perceived the disorder to be 
 the remittent fever, though in a slight or obscure form, that he 
 should have persisted in his mistakes to the last, converting a 
 mild disease into a severe one, that, against remonstrances which 
 should have opened the eyes of any man, and in a land and sea- 
 son of Malaria, where no man who had eyes could be supposed 
 capable of shutting them to the truth, he should have so perse- 
 vered in wrong, is nearly incredible. Whether Lord Byron would 
 have died of that fever, under proper treatment, He alone to 
 whom the book of Fate lies open, knows : but while many must 
 feel that indignation, as well as regret, which some would also 
 express under the same conviction, it is difficult at least not to 
 think, even under the most dispassionate view of the circum- 
 stances, that the death of this lamented personage was caused by 
 the ignorance of his physician ; if ever that act was committed by 
 physic. 
 
 To return to the Morea. Commencing at Gastouni, we find 
 the whole plain which includes the Alpheus and the other rivers 
 of this district, equally unwholesome, and to a wide extent ; 
 
MALARIA. 179 
 
 while, comparatively skirting the shore further to the southward* 
 it is sooner terminated by the mountains in this direction. Thus 
 the Malaria attends the rivers which flow into the gulfs of Koron 
 and Kolokythnia ; penetrating many miles along these vallies, 
 and re-appearing at Argos and at Napoli di Romania, as our own 
 countrymen have discovered ; while, morever, it occurs almost 
 every where along the promontory and round the eastern shore, 
 as far as Corinth and Megara ; extending even near to Athens, 
 nor omitting iEgina in this quarter. The ill fame of the plain of 
 Marathon has now also become familiar, as is that of the op- 
 posed shores of Negropont ; and if both coasts of the channel of 
 Talanda are insalubrious, that which reaches from Thebes as far 
 as to Zeitoun, penetrates into the interior, along the Salambria 
 and the Gaurios, even towards the declivities of Parnassus, main- 
 taining its pernicious character through this whole extent. 
 
 As to the whole of this part of Greece, and indeed of that 
 country generally, I may make the same observation as I did res- 
 pecting Italy, namely, that although what I formerly remarked 
 as to the drainages of the ancients and the fables of Hercules, and 
 what may be found in the writings ascribed to Hippocrates, testify 
 that such diseases existed, and that their causes were well under- 
 stood, yet there has probably been a great increase of insalubrity 
 since the classical times, from causes similar to those which I 
 then pointed out. Of these, the chief must be sought in geologi- 
 cal changes of the surface, produced by the action of rivers and 
 of the sea, and giving rise to new and pestilential alluvial lands ; 
 as also in new r modes of agriculture or of rural economy at large ; 
 those comprising, principally, the cultivation of rice and the 
 management of woods; while, as to this particular country, when 
 compared with Italy through the same period of time, it is easy 
 to see that much may be attributed to the consequences of mis- 
 government ; to diminished capital, industry, and perhaps also 
 knowledge, or, generally, to diminished care and improvement as 
 far as the lands are concerned. 
 
 The former great cause, unceasing, if slow, is that indeed in 
 which the whole world is implicated ; nor is it difficult to see, as 
 I formerly explained, that while the mountains shall flow to the 
 sea, increasing the plains, and, in creating new lands, providing, 
 in an increase of fertility as well as of extent, for an augmenting 
 population, so must the augmentation of insalubrity and the in- 
 crease of diseases accompany these changes. And while, in such 
 cases, increase of industry and attention is required to meet the 
 evil, it is the misfortune of Greece, as it has been of many other 
 declining or fallen states, to have suffered a loss or diminution of 
 both, or of that at least which alone could have maintained and 
 stimulated them, from the effects of its unhappy and lamentable 
 
180 GEOGRAPHY OF 
 
 political condition. Did any visionary geologist thus choose to 
 speculate on the day when the mountains shall be levelled with 
 the plains beneath, an event which, in a period beyond the range 
 of calculation, must happen should our globe endure thus long, 
 he must also be prepared to view that previous period when, 
 whatever vegetation or whatever animals may possess the marshes 
 and plains of that world, it will scarcely be man ; since, long be- 
 fore this, he will have been driven from them, as he has been 
 from the Pontine marshes, by that plague which Nature is even 
 now daily preparing in silence to keep his unmanageable increase 
 within bounds. 
 
 To return to Larissa, we may include the whole plain of Thes- 
 saly within the range of Grecian Malaria ; while its history may 
 also teach us what must be expected when, at some far distant 
 day, as I once before suggested, the destruction of the bed of the 
 St. Lawrence from Niagara backwards, shall, if it does not simi- 
 larly drain Lake Erie, expose at least a large portion of the bot- 
 tom of that lake, and probably induce many other great changes 
 on the surrounding country. From Larissa, the range of Olym- 
 pus ensures the salubrity of a considerable space along this shore ; 
 but the Oleander, among other vegetable beauties, the infallible 
 warning of Malaria wherever it occurs, soon begins to tell the tale 
 of that tract which, reaching along this shore to Salonika, and be- 
 yond it to Panomi, occupies the Venetiko as far as Grevno, and 
 extends so widely throughout all these vallies and plains of Ma- 
 cedonia. 
 
 From Erissos to Cavallo, and all through the gulf of Contessa, 
 there is a similar tract of unhealthy land : and if, beyond this, my 
 information respecting the coasts of the Grecian mainland draws 
 to a close, I can still point out the coast, and also the valley for 
 a long space, which extends from Enos to Ipsala and towards 
 Adrianople. 
 
 In the islands of the Archipelago, the entire of Lemnos, and a 
 great portion of Imbros, are similarly pernicious ; as is all that 
 part of Mitylene which surrounds the bay, together with the east- 
 tern side of Scio, almost the whole of Naxos, a part of Cerigo, 
 and the whole of Milo and Paros ; the latter island being peculi- 
 arly pestiferous, as I formerly had occasion to remark when 
 speaking of the fate of the Russian army at Naussa. In Candia, 
 there are various unhealthy tracts ; namely, at Candia itself; at 
 Sudo, Port Stauro, and Settia ; and thus, certain parts of Cyprus, 
 particularly near Famagusta, are among the most notoriously 
 poisonous climates in the Mediterranean, as Dr. Clarke has re- 
 marked ; though paying less attention to this subject than, from 
 his personal sufferings, united to his medical knowledge, might 
 have been expected. 
 
MALARIA. 181 
 
 I must pass over the African shore of this sea, where, neverthe- 
 less, there occur many unhealthy spots ; as is the case between 
 Susa and Bona : partly because my information is imperfect, and 
 partly because it is less interesting to general readers than the 
 countries of Europe which they may chance to visit. Thus I 
 must proceed to the shores of Spain : respecting which however, 
 my information is very scanty, and, what is worse, incapable, at 
 present, of being augmented. Tracing from the Pyrenees, there 
 is an insalubrious tract near the Gulf of Rosas and including Ge- 
 rona, of no inconsiderable extent ; while, beyond the mountains, 
 a similar one occurs at Tosa and St. F. de Guixolos. That 
 Barcelona is not the very healthy place which it was once thought, 
 has been recently proved ; but the first united and extensive ter- 
 ritory of Malaria succeeding this, is that which commences to the 
 southward of Tarragona, occupying the mouths of the Ebro, and 
 extending many miles along its course into the interior; while it 
 ranges the whole shore, beyond Cape St. Martin to Benisa. This 
 is the rich, the fertile, the envied Valencia ; a province in which 
 this plague is, unfortunately, not limited to the sea coast, since it 
 occupies the entire country, wherever that is flat and fertile ; ex- 
 tending to Segorbe in one part, and similarly along the Xucar, 
 and, from Valencia, far along the course of the Guadalaviar. 
 
 To pass over some other spots of less note, Murcia is the cen- 
 ter of another similarly pestilential tract, reaching nearly from 
 Alicante to beyond Cartagena ; this latter district being the rival 
 of the Pontine marshes, and the grave of those who, even for a 
 few months, nay, often during a few days, are condemned to la- 
 bour in its destructive vicinity. And if, still further westward, I 
 have reason to believe that very little of this coast is exempt, 
 even to the mountains of the interior, I can only point out, as es- 
 pecially notorious, the country round Aguilas, the vallies extend- 
 ing inwards from Almeria, Adra, and Salobreno, and the flat lands 
 from St. Roque, as they hem in Gibralter ; itself placed beyond 
 the reach of this plague, by its elevation, united, probably, to its 
 particular ventilation. 
 
 The Atlantic shores of Spain, henceforward, present one con- 
 tinuous tract of pestilential land, which, if comparatively narrow 
 from Gibralter to Trafalgar, soon enlarges so as to reach even 
 to Medina Sidonia ; while, if Cadiz escapes much of the evil, it 
 is only from holding a position which, if, sometimes, and in some 
 seasons, comparatively secure, is not protected from these winds 
 at least, which blow from the marshes of Chiclana to the south- 
 ward and eastward. Here indeed the easterly winds deserve the 
 reputation which I formerly attempted to adjust ; nor would it 
 now be difficult to see over the territory which I have already 
 
 ~~„,„~j :_ iu* i i.i •_ l: • a :~Ui. i — j~ 
 
182 GEOGRAPHY OF 
 
 terminer!, by a due comparison of the localities of places generat- 
 ing Malaria and of those receiving it, under the influence of this 
 wind or any other ; while a similar investigation of the geogra- 
 phy and of the facts which relate to the existence of disease, on 
 the one hand, and to its remote probable causes, on the other, 
 compared with the results as they follow certain winds, would 
 confirm, over every part of the Mediterranean, and indeed of the 
 world generally, the view which I formerly attempted to estab- 
 lish. With respect to Cadiz, I ought however to remark, that it 
 has been the subject of a peculiar controversy as to this question ; 
 a dispute, the causes of which are similar to those in which the 
 West Indies, Gibralter, and New York have been involved, and 
 into which, of course, I dare not enter ; while not doubting, that 
 whatever may have been the celebrated " yellow fever," this city 
 is subject to the influence which I have been describing, though, 
 assuredly, in a less degree than if it had not that protection which 
 it derives from its insulated position. 
 
 But the whole of this portion of Andalusia is more or less in- 
 salubrious, and often very highly so; while if Arcos and Seville 
 are included within this boundary, so it reaches to Lagos, or al- 
 most to Cape St. Vincent: extending also along the Guadiana, 
 over the whole plain, to Badajos and Merida, and much further 
 indeed than my imperfect knowledge enables me to pursue it : 
 though I may remark that where that river disappears to form 
 great marshes at Alcaza, it produces a particularly unhealthy dis- 
 trict. 
 
 I must here indeed cut short this brief notice on Spain, at least 
 for this part ; since I can find no further information respecting 
 the interior country, beyond the general notices of superficial 
 travellers ; and having also lost my pilot, I must be even more 
 brief respecting the northern shore. Notwithstanding the large 
 portion of this country which is occupied by mountains, it is im- 
 possible that Spain can be exempt from Malaria, even all through 
 its interior as well as its sea coasts ; amid its confined vallies, and 
 by the banks of its numerous rivers. Of this, indeed, we find 
 casual evidences in abundance, yet none that I can quote with 
 satisfaction ; while, though this splendid, but ill-fated country is 
 not deficient in philosophical writings, I have not had the good 
 fortune to discover any work even alluding to a subject which 
 has formed almost a source of occupation for the authors of Italy. 
 That the wretched state of medical science in Spain may be the 
 cause, in some measure, of this neglect, is not improbable ; since 
 this country is not wanting in statistical writers, while this is a 
 branch of statistics which seems, by a sort of tacit consent, to 
 have been left to a profession, which, surely, has not done it any 
 very great justice, any where. 
 
MALARIA. 183 
 
 For the purpose of preserving the coast line in this sketch, I 
 may take up Portugal from this point. That the shores and the 
 valley of the Tagus are highly insalubrious, and particularly about 
 the salt marshes and manufactories, is now familiar ; while the 
 unhealthy region extends far up this great river to Santarem, 
 Abrantes, and far beyond it, so as to extend in this direction into 
 Spain, even as far as Truxillo. If Lisbon itself is exempt, as is 
 the high and irregular land on the opposed side of the Tagus, the 
 insalubrious country commences with the plain on the right bank, 
 while, on the left, it extends far through the level or open country 
 from Aldea Gallega. On the right, towards Abrantes, Golagao 
 is peculiarly notorious ; while at Azambuja, and thence to Santa- 
 rem, lies that proverbially pestiferous region, of which the very 
 name excites terror. Nor is the Douro exempt, and still less the 
 watery country of Entre Minho and Douro ; while a hundred 
 separate spots along this shore, which it would be tedious to 
 name, reaching even to Ferrol, and all of them the exits of rivers 
 or the mouths of valleys, attest the universality of a general rule 
 which will always be a safe guide in forming a judgment on this 
 subject. The same is true of the whole shore of the Asturias, 
 from St. Sebastian to near Cape Ortegal, though the narrow or 
 scattered extent of plain in this tract, and the general hilly nature 
 of the country, confines the insalubrity to different very limited 
 spots, and, as usual, to the seats of rivers generally ; while I may 
 also remark, that the peculiar ventilation of the whole of the At- 
 lantic shores of the peninsula, united with, and partly regulated 
 by the positions and altitude of the mountains, renders all this 
 division less virulently unwholesome than the similar situations 
 within the Mediterranean. 
 
 With respect to the extent and the localities of the Malaria in 
 France, I must commence by regretting that I have lost my guide 
 as to the sea coasts, and that, as I formerly observed, I have been 
 disappointed in the expectations which 1 had formed from Mon- 
 falcon's work. But however imperfect this sketch will therefore 
 be, I shall probably still surprise those of our own countrymen to 
 whom this subject is new, and even those who, acquainted with 
 the evil reputation of Italy on this point, and perhaps not a little 
 guided also by the association of terms, are almost inclined to think 
 that Malaria is an exclusively Italian substance as it is an Italian 
 word. 
 
 I may commence, as before, with the sea shores, and by the 
 general assertion, requiring in reality but few exceptions, of which 
 Cherbourg is one, but of which St. Malo is not one, in spite of its 
 apparently promising situation, that from Dunkirk, or, in strict- 
 ness, as to present France, from Calais, there is not a sea port on 
 the coast, as far as St Brieux, where a stranger can remain in 
 
184 GEOGRAPHY OF 
 
 summer, or rather, after July, without the hazard of fever. That 
 the residents comparatively escape, is only a consequence of what 
 I have fully explained, as far at least as it is explained, in the 
 medical part of this work : but it will be found that every flat si- 
 tuation on this long line of coast is unhealthy, though the degree 
 of insalubrity is far inferior to what it is within the Mediter- 
 ranean. 
 
 Not to be unnecessarily minute, the insalubrious nature of the 
 land round Calais is quite notorious : and though Boulogne is in- 
 finitely less hazardous, there are many English residents who have 
 had to repent the day when they chose this as a dwelling place. 
 To pass over many other places, the same is true of the mouth 
 of the Seine, generally, as at Havre and elsewhere; and of many 
 of the situations along the whole of this shore, as far as Carentan, 
 including Pont L'Eveque and Caen ; while, within the land, the 
 Malaria, to that moderate degree, compared to Italy, with which 
 it affects this north coast of France, extends into Normandy in 
 numerous places along the courses of the rivers, and through the 
 flatter and fertile plains : as is the case, among others, with the 
 valley of the Ague. 
 
 But on this coast, the most pestiferous tract is one, of which 
 Avranches and Dol may be taken as the principal points, since 
 the higher lands and shores of the promontory escape for the most 
 part ; nor, as far as relates to inveterate tertians, is this marshy 
 and flat district of Normandy excelled even by Holland ; the 
 whole bay, in fact, at this part, being a pest-house as to endemic 
 fevers; and even these less poisonous portions of France being 
 subject to occasional severe epidemics, as I have had formerly oc- 
 casion to notice respecting Bernieres. 
 
 With respect however to many of the towns and places along 
 this shore, it is surprising, and sometimes not unamusing, to find 
 how this truth is suppressed or denied, as is so generally the case 
 everywhere ; so as to mislead all but a physician, intent on this 
 subject, and not to be deceived by what, if he knows it at all, he 
 is always prepared for. It is only " la fievre," or " la fievre du 
 pays," or " la fievre tierce :" while the English visitors or resi- 
 dents, ignorant of the subject, not uncommonly of every subject, 
 perhaps incredulous or contemptuous, holding aloof from the peo- 
 ple, or unacquainted with their speech and manners, and more- 
 over, from that " morgue aristocratique ,, which is the effect of 
 what foreigners satirically call an English education, despising 
 and overlooking the People everywhere, remain ignorant of the 
 diseases in the midst of which they are living, till their own turn 
 arrives to suffer ; even then not understanding that the " fierre du 
 pays" is the fever of Malaria, but attributing their misfortunes to 
 eating figs or drinking French wines, or occupying a damp house. 
 
MALARIA, 185 
 
 If I have, more than once, found a whole country suffering from 
 these diseases, where I was previously assured that Malaria was 
 unknown, 1 have acquired a right to be incredulous as to the sa- 
 lubrity of many places, where, nevertheless, I cannot at present 
 prove the existence of this plague. 
 
 The coast of Brittany has the reputation of being exempt as far 
 as Brest ; and I cannot prove the contrary, however I may sus- 
 pect the river of Morlaix among other places ; but assuredly it 
 cannot be free from pernicious ground within that bay, nor at 
 Quimper, nor in the Morbihan ; as it certainly is not at L'Orient 
 and Vannes, though the whole evil fame is swallowed up in the 
 terrible repute of what is properly called Basse Bretagne ; a 
 tract of great extent along the shore, and reaching inland even to 
 Rennes, so as to occupy a great portion of the departments of the 
 Morbihan, He et Vilaine, and the Lower Loire. What Nantes 
 itself is, in this respect, is now well known, even to our own 
 countrymen who have thought fit to resort to it for economy-— 
 and for climate. 
 
 Such is the character also of La Vendee, not only along the 
 coast but in the interior; Beauvoir sur mer and Lucon being pe- 
 culiarly notorious : and as we draw towards the south, the fevers 
 also assume a character of greater malignity, while further, as in 
 Italy, which France now begins to emulate in all points of evil, 
 becoming frequently and severely epidemic in autumn, and after 
 peculiarly hot seasons. Nor is it otherwise from the mouth of 
 the Sevre to the Gironde ; Rochefort being noted for its insalu- 
 brity, as is Brouage, and as are considerable tracts on the Cha- 
 rente : while a great portion of Poitou in the interior, is among 
 the most notedly pestiferous districts in France ; being nearly 
 connected with a very extensive range of the same kind, as will 
 appear more particularly hereafter in sketching the extent of Ma- 
 laria on the Loire. Hence to Bayonne I am unacquainted with 
 the coast ; but a recent epidemic mortality at Bordeaux, which I 
 had formerly occasion to mention, is sufficient to prove that this 
 is not the salubrious spot which it had been reported by our coun- 
 trymen. 1 am indeed informed that great portions of that exten- 
 sive and well known district called the Landes are extremely in- 
 salubrious, not only on the coast but in the interior ; a circum- 
 stance exceedingly probable from the peculiar character of much 
 of that singular country. 
 
 With respect to the Mediterranean shore of France, I may al- 
 most say that it is one entire range of Malaria from the Pyrenees 
 to the Alps, and in some places scarcely less pestiferous than the 
 worst parts of Italy. Such are the salt marshes of Peccais in Lan- 
 guedoc, and very universally the whole tract of the Bouches du 
 Rhone, among which Camargues is especially notorious, to a very 
 
]86 GEOGRAPHY OF 
 
 great extent in the interior ; since, as I shall presently show, this 
 pernicious region reaches even to the junction of the Saone at 
 Lyons, and beyond it. The coast of Provence, between Mar- 
 seilles and the mouth of that river, is similarly bad, as is the inte- 
 rior tract in this particular quarter ; and, on the other side, Nar- 
 bonne is not less noted for its unhealthy climate. 
 
 On the Italian side, Frejus seems however to be nearly the 
 boundary of this region : but if Montpelier has escaped this evil 
 reputation, among some other places, it is somewhat difficult to 
 believe its claims, when Cette is as unhealthy a place as can well 
 be ; though it must be allowed, that on the principles formerly 
 explained with regard to the resistance of towns, the greater cities 
 may here be exempt, while the smaller ones and the proper 
 country suffer. But I need not be more minute as to this shore ; 
 since no one can look at its topography, almost even in a map, or 
 visit any town, or examine the population, without being convinc- 
 ed of the fact, and without also becoming speedily aware of the ex- 
 tent of the evil. In as far as Toulon and Marseilles may escape, it 
 is partly owing to the magnitude of those towns, but partly also to 
 the form of the land for a certain space along this shore : and thus, 
 in some other places, where there is no margin of flat alluvial land, 
 or where that is very narrow while the towns are situated on the 
 declivities, the insalubrity is comparatively small, or is but casual, 
 or is experienced by those only who may be engaged in these 
 deleterious spots. 
 
 To proceed inwards from the mouth of the Rhone, I believe I 
 need scarcely say that Avignon is included within this unhealthy 
 country : as its character is now tolerably well known to travel- 
 lers. Thus does the Malaria attend us in our progress along the 
 river, and on both sides, even to a considerable extent laterally 
 in many places ; numerous and considerable tracts of this nature 
 occurring in particular in the department of the Isere, and also in 
 those of the Drome and the Ardeche. But to pass over many in- 
 dividual places along the line of this river, or, continuing that 
 line on the Saone, even to Macon, and beyond that town, it is 
 here that there occurs one of the most pestiferous districts in all 
 France, as I have more than once had occasion to point out in 
 discussing the effects of Malaria. This is the department of the 
 Ain, in which that portion called Bresse is also the most notori- 
 ous. This almost undrainable country is a collection of forests, 
 marshes, and pools ; it being computed that there are about 
 1,800,000 acres completely barren, from these waters, and the 
 chief pools or lakes being those of Grand Birieux, les Brevannes, 
 Foret Curtilet, les Vavres, and Glarins ; and the principal marsh- 
 es those of St. Croix, Joyeux, Buelle, Vial,Molieres, and Echets. 
 Hence it is, that the towns of St. Trivier, Chatillon, Villars, St. 
 
MALARIA. 187 
 
 Nizier, Marlieux, and St. Paul, among others, are peculiarly insa- 
 lubrious : while the picture which has been drawn of the state of 
 the population, by Monfalcon, the author from whom I have bor- 
 rowed these remarks, will be given in a subsequent chapter. 
 
 The pestiferous lands which abound along the course of the 
 Loire, commence almost with the river itself, which, on this 
 point, will scarcely yield to the Po and the Adige. It is here that 
 the notorious plain of Forez lies ; while about Montbrisson and 
 St. Rambert, there are not less than four hundred and fifty lakes 
 and pools, together with many marshes, such as that of Ailland. 
 The whole of this tract is scarcely habitable, except in winter ; 
 since the bad air ranges even from April to November, forming a 
 larger season of disease than what occurs generally in Italy : be- 
 cause, at Rome, that scarcely commences till St. John's day. 
 The fevers are eternal, and consist chiefly of never-ending ter- 
 tians and quartans ; while the people are universally stupid, indo- 
 lent, sallow, apathetic, and more like walking skeletons than liv- 
 ing men ; becoming old, if they live so long, at forty-five, and 
 entirely decrepid if they survive beyond fifty. The population 
 thus dies off rapidly, requiring perpetual renewal; yet even in a 
 region so utterly mortal as this may safely be called, the high wa- 
 ges maintain an unfailing supply of immigrants ; so thoughtless is 
 mankind. 
 
 Pursuing the same course we find the similar district of Brenne 
 in Bas Berry ; the same land of lakes and fevers, and if worse 
 can be, worse. The children, here, are ill even from their birth 7 
 and often die of the diseases of the climate before they are seven 
 years old ; while the general population, living a life of misery, 
 scurvy, dropsy, and fevers, becomes old at twenty ; very few 
 reaching the extreme old age of fifty. 
 
 If the banks of the Loire smile in the imaginations of those 
 whose knowledge is derived from poetry and romance, if Sterne 
 and his Maria have enticed many a wandering Englishman to 
 breathe its zephyrs and listen to its pipe, and — to lay up a long 
 stock of bitter repentance, let future speculators qualify the page 
 of fancy with those of Monfalcon, ere they trust themselves to its 
 seductions, or to those of its ally, the Cher. It is here that he 
 will detail to them the delights of Sologne, fit rival in attractions 
 to the Maremmas of Tuscany and Rome. 
 
 This most detestable tract occupies a superficial space of about 
 two thousand three hundred square miles, chiefly in the depart- 
 ment of the Loire and Cher in the Orleannais ; reaching from 
 Blois to Henrichemont, and including some tracts near Orleans 
 and Gien ; thus forming a large oval, beset with marshes and 
 pools, and chiefly so near Orleans and Romorantin. What the 
 diseases are, and what the misery of the people, I need not re- 
 
188 GEOGRAPHY OF 
 
 peat, since it is but to tell the same tale again ; while, on different 
 occasions, in various parts of this entire work, I have named this 
 very tract as evidence or otherwise relating to the subjects under 
 review. 
 
 I need not pursue the Loire to Nantes, where I formerly left 
 off; since, if there is no pestilential tract of equal integrity and 
 magnitude with that which I have just described, the same cha- 
 racter of country occurs along the whole course of that river, 
 and often to a considerable extent from its borders. Thus also 
 Poitiers, as I lately suggested, is the center of a district not less 
 insalubrious than many others which! have here described, if less 
 extensive and united than Sologne : but the truth is, that with 
 respect to the interior of France, so numerous are the tracts and 
 spots of this nature, from the peculiar character of the rivers and 
 the distribution of the land, that an entire catalogue would form 
 almost a geographical grammar of the country ; while my object 
 here has been to select those places which are most notorious, or 
 which, as the resort of English residents, seemed to demand an 
 especial notice. I must not however conclude without remark- 
 ing, that there is a great extent of insalubrious country in the de- 
 partment of the high Garonne, and also, to make a somewhat 
 sudden transition, that while the Seine is a guide to many similar 
 tracts, its influence extends widely above Paris and over the 
 country about Laon. 
 
 Respecting Flanders, I know not that I could say any thing 
 which is not already familiar to every one, while the land here 
 speaks for itself; and as to Holland, its name alone must serve, 
 since it is the land kut' e|o^»y of Malaria and fogs. Of Germany 
 I am ignorant, at least as far as details are concerned, as the non- 
 German world at large appears to be ; but it requires little read- 
 ing to know that the flat and marshy tracts along the banks of the 
 Rhine at least, and many also of its towns, among which I may 
 name Oppenheim, may compete for the palm of fevers with Rome 
 or Holland ; while as far as the Danube is German, it is also pro- 
 ductive of numerous unhealthy tracts. , In Switzerland, I already 
 pointed out the suspicious lakes and meadow lands ; and if, for 
 this country also, I can not find many specific details, I can, from 
 Zimmermans authority, accuse the canton of Underwald, and 
 particularly Stanz ; where an epidemic fever of this nature was 
 so severe in 1717, that the patients very commonly died in the 
 second fit. It would be abundantly easy to divine where Swit- 
 zerland, and Germany also, are insalubrious : but I have chosen 
 to make this chapter a record of ascertained facts, since any 
 reader, versant at once in physical and political geography, can 
 easily do for himself all that 1 could do for him. 
 
 Henceforward indeed I must contract altogether ; since I can r 
 
MALARIA. 189 
 
 discover nothing but a few casual notices in books of travels and 
 statistics; willing enough to leave to others the remainder of a 
 somewhat wearisome task and no very lively chapter. But there 
 is a general accusation against the whole of the chores of the 
 Baltic ; against Denmark very widely, and especially also against 
 Samogitia and Courland ; while Stockholm is familiarly known 
 for the severity and inveteracy of its intermittents ; so little is a 
 northern latitude a security, where there are wet lands and a hot 
 summer. The marshy forests of the Kama and the Viatka in Po- 
 land, are equally notorious ; and it would appear indeed that the 
 fevers of Malaria abound in great severity, generally, through all 
 the woody and marshy regions of these countries, even when 
 placed far to the north; since even Lapland itself does not ap- 
 pear to be exempt. 
 
 If we approach the southern provinces of Russia, it is to reach 
 a country than which none more pestiferous exists in Europe, 
 and scarcely indeed in the tropical climates ; since such is the 
 history of the country of the Don, and of the Crimea, as of Bessa- 
 rabia and the Turkish provinces here, or generally, of the whole 
 of the flat and marshy lands which border the great rivers and 
 the Black sea. The death of Howard would have rendered that 
 country notorious, even without the travels of Dr. Clarke ; but 
 as I must here end with Europe, for want of the means of pursu- 
 ing it further with that minuteness of detail and validity of autho- 
 rity which form the grounds of this chapter, I may remind the 
 reader of Moldavia and Wallachia, formerly noticed, and of Hun- 
 gary, the grave of armies ; the latter country being, over large 
 tracts, marshy through half the year, and when drying, producing 
 the same effects which arise in Africa and in the East from that 
 j cause. 
 
 I might detail the geography of the Malaria of America at con- 
 | siderably more length, since the information here is more perfect, 
 | but that I am unwilling to extend a chapter, the length of which 
 ! is already formidable, and since it is, practically, less interesting 
 I than the countries especially frequented by our travellers, to 
 i which I have, preferably, given the room which I could spare. 
 | Generally therefore, I must observe, this plague occupies the 
 I Canadas, in summer, every where along the shores of the great 
 ! lakes and rivers ; the character being commonly that of inve- 
 | terate intermittents ; while, whether Lake Erie is worse than the 
 i others or not, it has the worst reputation, as have, elsewhere, the 
 ! banks of the Mohawk river, and the Genesee. With respect to 
 I the United States, formed of alluvial land as they chiefly are, 
 Volney remarks, that out of a space of three hundred leagues, he 
 did not find twenty houses free from the fevers of Malaria : the 
 iaost distinguished places, nevertheless, being the course of the 
 
190 GEOGRAPHY OF MALARIA. 
 
 Ohio, rendering even the interior State of Kentucky insalubrious,, 
 the towns of Norfolk, Charleston, New York, Philadelphia, New 
 Orleans, Savannah, and Pensacola, with Baltimore, and almost 
 the entire states, in fact, of Virginia, the Carolinas, Georgia, the 
 Floridas, and Louisiana. 
 
 Such are the United Provinces of this great country ; while in 
 many of the southern states, the evil has, for some time, been so 
 rapidly increasing, as almost to threaten the abandonment of the 
 lands ; the proprietors having, in reality, in many parts, been 
 obliged to quit their houses and estates and retire to the towns, 
 even against an express law which compels their actual residence ; 
 thus leaving them to the superintendence and occupation of their 
 slaves, and offering a strong argument in favour of a black popu- 
 lation at least, if not of an enslaved one. But to cut short this 
 portion, the same plague is found to prevail very widely even 
 through the extreme interior, and amid the newly settled or still 
 uncleared lands, along the course of the Mississippi and its endless 
 tributary streams ; to the no small surprise and the serious griev- 
 ance of the numerous settlers by which such a state of things was 
 not contemplated. What the fate of much of this new country 
 may ultimately be in this respect, it is difficult to foresee, when 
 we reflect on the numerous circumstances already stated, which 
 modify the production and propagation of Malaria, and where so 
 much is yet to be done as to alteration ; though it is to be suspec- 
 ted that no changes and no cultivation will ever bring into a state 
 of salubrity, a country so abounding with alluvial plains, even in 
 the interior, and so extensively the produce of its numerous and 
 enormous rivers. 
 
 Familiar on this point as are the West Indian islands, and well 
 known as are even their pernicious spots, I need only name Ja- 
 maica, St. Lucia, St. Domingo, Martinique, Dominica, and St. 
 Vincent, as the most remarkable ; while Spanish America, com- 
 mencing with Vera Cruz and ending with Acapulco, would itself 
 furnish a catalogue almost commensurate with its sea coasts, and 
 which I must therefore pass over. For the same reasons, an 
 enumeration which would scarcely end, I must omit all notice of 
 the other two great divisions of the world, and terminate a chap- 
 ter which some one will perhaps hereafter be tempted to convert 
 into a book ; a work which, however unamusing to himself the 
 labour may be, or however dull to those who may not be called 
 on to profit by its advice, will reward the author with the con- 
 viction at least that he had done good to many, and made himself 
 useful in his generation. 
 
 If I have here omitted to notice the insalubrious parts of our 
 own country, there were many reasons against the attempt. The 
 more notorious ones are familiar to every one who has the slight- 
 
NATURE OF MALARTA. 191 
 
 est topographical knowledge as to his native land ; while, to exe- 
 cute it in such detail as to render it extensively, or really useful, 
 would in itself demand a small volume. And if, moreover, it 
 could scarcely be executed by any one without a very minute in- 
 vestigation, and without a peculiar species of topographical rather 
 than properly geographical knowledge, the attempt would not 
 only be offensive to many individuals, but might possibly prove 
 injurious to some ; as I formerly suggested in excuse for my own 
 suppression of necessary evidences. Offence at least could 
 scarcely be avoided ; when the phlegmatic Middleburgher rouses 
 all the indignation which his Boeotian feelings can muster, to re- 
 pel the insulting notion that the three or four thousand victims to 
 his September days have been sacrificed to his odorous ditches. 
 And whatever proof such a topographer might produce, to show 
 that his object was to save human life and diminish human suffer- 
 ing, it is more probable that he would be contemplated as the sa- 
 tirist of his country, the unsolicited censor of sewers and drains ; 
 an alarmist in the eye of the world, however willing, himself, to 
 bear all, and to wait for the day when, whatever scorn he may 
 have endured, his labours will have become profitable to those 
 on whose account they were undertaken. 
 
 CHAPTER X. 
 
 On the Naturt of Malaria. 
 
 If it is a common practice with medical writers to produce the 
 largest dissertations on the subjects which are the least under- 
 stood, I fear that I must adopt the contrary practice ; and thus 
 atone for the emptiness of this chapter by its brevity. Perhaps 
 indeed the best, as the truest account of the nature of Malaria, 
 would be an acknowledgment of utter ignorance ; but it is at 
 least my duty to say that attempts have been made to examine in- 
 to it ; a few attempts, to balance a much greater weight of con- 
 jecture. 
 
 That the poison of marshes consisted in animalculas invading 
 
192 NATURE OF 
 
 the bodv flirough the lungs, sometimes, I presume, through the 
 stomach also, is a speculation which dates as high as Lucretius, 
 Varro, and Columella, which seems to have been renewed in the 
 days of the microscope, by Kircher and some others, and appears, 
 naturally enoughs to have found favour with Linnaeus. A mytho- 
 logv somewhat more remote than it would here be convenient to 
 inquire of, found a sufficient reason in the Dogstar ; but whether 
 this doctrine gave rise to the malign aspects which served the 
 purpose of a cause to the age of astrological philosophy, it is not 
 worth inquiring. The chemistry which had not yet succeeded 
 in emancipating itself from the planetary influences, and to which 
 the two sweeping, and not less unmeaning terms, salts and sul- 
 phurs stood in lieu of the labour of observation and thinking, 
 equally, concluded that the poisonous air of marshes consisted of 
 sulphureous and saline vapours : and if such was a satisfactory 
 explanation to Ramazzini and many more, authority like that 
 could not fail to exert its usual influence. When mechanical phi- 
 losophy began to apply its doctrines to the human body, there 
 was no good reason why Hoffman should not conclude that the 
 whole secret lay in the diminished elasticity of the air : but this 
 theory, never much respected, seems to have bowed before one 
 of mueh better fortune, which accounted for the whole by the 
 three terms, heat, moisture, and putrefaction, duly expanded and 
 discussed. A theory of much better fortune, certainly: since it 
 is not yet out of fashion ; inasmuch as no small number of modern 
 physicians, easily satisfied as it may be supposed, with words, 
 still attribute the fevers of summer in question to heat and mois- 
 ture alone ; as moisture and cold are equally satisfactory solutions 
 of the intermittents of spring. 
 
 A new and a better chemistry verv naturally induced better 
 philosophers to seek for a new chemical theorv on this subject ; 
 and I believe that Volta must be allowed the merit of the first 
 suggestions and the first experiments on this ground. Naturally 
 also perhaps, these philosopher- the poison in question 
 
 among the ascertained chemical gases : but the honour which any 
 one can claim is too small to render itnecessarv to assign to each 
 his gas and his theory. It must suffice, in this very brief sketch, 
 to say that amoug these persons, are found the names of Baumes, 
 (Mia, Chevreuil, Textoris, Balme ; and that the accused gases 
 have been carbonic acid, azote, hvdrocarburetted gas, hvdrophos- 
 phuretted gas, hydrosulphuretted gas, and even ammonia ; to say 
 nothing of an yet undiscovered compound of azote and oxygen, 
 called septon. 
 
 But justice must now be done to those who have attempted, 
 by the means of analysis which modern chemistry furnishes, to 
 examine the air produced by marshes, and to inquire whether it 
 
MALARIA. 1 93 
 
 did not really contain some peculiar volatile substance, or com- 
 pound and unknown gas, the true source of the evil ; since I need 
 not say that the known ones which have been enumerated are 
 not the poisons in question, inasmuch as they can be applied to the 
 body in the laboratory, in a much more effectual manner than na- 
 ture can ever furnish them, yet without exciting fevers. 
 
 The eudiometrical experiments of Gattoni and Moscati pro- 
 duced no results, as might have been anticipated : a more rational 
 mode of experimenting, and for a different object, was attempted 
 by De Lisle, Vauquelin, Julia, Brocchi, and others ; and if the 
 problem could have been solved by the analytical powers which 
 modern chemistry furnishes, we might have expected the solution 
 from the hands at least of Vauquelin. It is unnecessary to detail 
 failures, and equally so to describe the nature of the attempts, 
 though rationally conducted. What was considered as animal 
 matter, was found, repeatedly, in the condensed vapour or dew, 
 of the grounds in question : but how far this fact may be connect- 
 ed with what is sought, we can scarcely conjecture. Malaria, 
 like contagion, like odours, remains a problem for future chemis- 
 try ; nor must we blame those who have been unable to produce 
 results without means. 
 
 Thus must I terminate what I need not discuss further, by re- 
 ferring to these authors, those who may possess any curiosity, as 
 to the attempts in question : but there remains a portion of this 
 subject, obscure as it is, which must not be passed over ; little 
 satisfactory as it is to inquire about the possibility of modifications 
 in any substance, when we are ignorant of the very nature of the 
 substance itself. That question is, whether Malaria can or does 
 vary in its composition or nature, or, in its qualities; whether, in 
 different places or climates, or as proceeding from different soils 
 or substances, it possesses diversities of character. 
 
 It is plain that we have no mode of examining this subject but 
 by the road of effects, unless any analogy derivable from conta- 
 gion can be also drawn into this service. In as far as any priori 
 conclusions of this nature might be suggested, from considering 
 the chemical varieties in the plants by the decomposition of which 
 it is produced, I have said all, as far as I know, which could bear 
 on the question ; and it does not lead to any satisfactory conclu- 
 sions. And as I have already noticed this subject, when ques- 
 tioning whether the effects of Malaria in producing, respectively, 
 remittent or intermittent, depend on the mere quantity in which 
 it is applied, or on any peculiar virulence in its nature, having 
 also pointed out such collateral causes as might, by uniting to its 
 action, modify its effects on the body, there is not much remaining 
 to be said in this place. 
 
 We may commence by taking contadon as an analogy ; but 
 
104 NATURE OF 
 
 even here, I dare only suggest, that as this chemical compound, 
 produced out of the few elements of the animal structure, does 
 possess many marked varieties productive of as many distinct dis- 
 eases, it is possible that a compound formed of the vegetable ele- 
 ments may be equally susceptible of diversities capable of produc- 
 ing the different diseases which arise from its action. It may in- 
 deed be made an objection to this view, that many of these latter 
 disorders pass into each other, as if the actions of the body itself, 
 and not differences in the poison, were the causes engaged ; yet 
 they who will meditate on the facts, as I dare not explain them 
 here, will see that this is not an objection of universal applica- 
 tion. And, granting any such diversity, even to a moderate ex- 
 tent, we might thus learn to explain many facts relating to the dif- 
 ferent action of this poison under different circumstances, which 
 have long been a source of difficulty to physicians. 
 
 But, after all, we must come to experience ; and I shall here 
 state the few facts of any great importance which I have been 
 able to select as bearing on this question ; while I will not again 
 renew the inquiry as to the effect of collateral causes, since, of 
 this, physicians can easily judge ; while, it will be seen, that, as 
 to some of the enumerated facts, no explanation is afforded by 
 such causes. 
 
 If it is as true and as constant as it has been said, that certain 
 countries have a tendency to generate, especially, one mode or 
 variety of marsh fever, while, in others, some other variety as ex- 
 clusively prevails, it is probable that there really are essential va- 
 rieties of this poison ; since we cannot easily conceive how mere 
 differences of quantity should be so constant, or produce such 
 uniform effects ; while we, equally, know not how to explain this 
 on any view of differences in the predisposing or accessary causes, 
 seeing that these must be inconstant in their very nature. Thus, 
 it is said, that tertians prevail in Germany, and quotidians in Italy; 
 that, in Hungary, petechias are so frequent in marsh fever as to 
 be a marked peculiarity ; that the fevers of the Pontine marshes 
 are noted for the shortness of their intermissions ; and that Hol- 
 land is not less remarkable for the variety of its types than for 
 the slow progress of the diseases. In Spain, as in Africa and the 
 West Indies, the black vomit and the yellowness of the skin are 
 similarly characteristic symptoms ; in some parts of Italy, apo- 
 plexy is particularly common ; just as, with respect to more re- 
 mote varieties, there are some districts which seem especially to 
 produce Neuralgia, as I have remarked elsewhere of South Wales, 
 and as is also asserted of certain parts of India and Persia. 
 
 I might easily accumulate many more facts of this kind ; among 
 which the tendency of Indian and African Malaria to affect the 
 liver, and that of Walcheren the spleen, in addition to its singular 
 
DISEASES PRODUCED BY MALARIA. 195 
 
 effects on the biliary secretion, would not be the least remark- 
 able ; as it is also a noted one, that in every year, the fevers of 
 this place are marked by a combination of symptoms which is as 
 constant as it is peculiar. But to terminate, certainly not the 
 least curious part of this subject, whether it will be considered 
 as a proof of essential differences in Malaria or not, I shall end by 
 stating from, I believe good, as it is medical authority, being that 
 of a French physician, that even in almost approximate spots, 
 there are similar permanent differences : the fevers of Walcheren 
 differing materially from those of Bresken on the other side of the 
 Scheldt, and, in France, those of Rochefort being as completely 
 distinguished from those of the Lyonnais. 
 
 Thus I must terminate an inquiry which I have not the means 
 of illustrating further, and which must be left to future times and 
 increase of knowledge. Yet I must not conclude without saying, 
 that while some physicians have supposed that animal matter 
 could take a share in the production of Malaria, so as materially 
 to modify the character or virulence of the poison, 1 can find no 
 facts brought forward which deserve to be taken in evidence. 
 Like the whole of this dark question, this also must be left to 
 future investigation : while it is plain that it forms a very interest- 
 ing object of inquiry, both as to the philosophy of Malaria and its 
 diseases, and as to purposes of practical utility. 
 
 CHAPTER XL 
 
 On the general effects of Malaria upon the constitution of the in- 
 habitants of marshy districts, and on the diseases which seem 
 to be produced by it. 
 
 Had I been writing to the people of France or Italy, I might have 
 omitted a large portion of this chapter, since it could only serve 
 to remind such persons of what is far better known to them than 
 it can be to me ; but while I am sure that such a state of things 
 is scarcely suspected by the people of England, however much, 
 as travellers, many of them must be interested in the facts, J 
 have also reason to believe that it is much less known to the me- 
 
196 DISEASES PRODUCED BY 
 
 dical profession in our own country than it ought to be. For the 
 authorities, I might refer to a host of authors, Italian and French 5 
 but I need not here repeat names, of which the most important 
 are quoted in this book for various purposes ; while the facts have 
 been confirmed to me, partly by living witnesses in whom I can 
 place the greatest confidence, and partly by my own personal 
 observations. They who may have travelled with an observant 
 eye, in France, Italy, Holland, Sicily, Greece, or America, will 
 have little difficulty in recognizing the transcript of an original 
 which must often have attracted their attention. 
 
 It must not be understood that every one of the circumstances, 
 physical and moral, here noticed, occur in every pernicious dis- 
 trict ; since their number and intensity are proportioned to the 
 quantity or the virulence of the Malaria, and to other collateral 
 causes which it must be now unnecessary to enumerate ; but 
 France and Italy can produce examples, as can also many other 
 countries, where the facts are not exaggerated by the picture of 
 them here presented. And if England is a far more moderate 
 sufferer, it still possesses tracts, and includes people, among 
 which many of the lighter evils here enumerated will be found to 
 exist. Further than this, I need not explain what, without some 
 such explanation, might almost be deemed a caricature, or at 
 least a picture overcharged by the imagination : while the chapter 
 on the geography of Malaria will sufficiently indicate the places 
 where the extremes of its pernicious effects will be found. 
 
 That the residence of successive generations in a district of this 
 nature produces a degeneracy of the races, is amply shown in 
 various parts of France and Italy; and never more distinctly than 
 when the inhabitants of the marshy plains and vallies come into 
 immediate contact with a people of the same radical origin and 
 race, inhabiting the healthy, mountainous or hilly tracts which 
 bound or include these. The stature not only becomes reduced, 
 but deformities are frequent; while, anatomically the bones are 
 found to be effected ; their extremities in particular being unusu- 
 ally large and spongy, and rickets, as a positive disease, being 
 also an implicated consequence. 
 
 The colour of the skin, and the general superficial aspect of 
 the people in these cases, has never failed to attract the attention 
 of even the most cursory travellers. The former is sallow, or 
 yellow, or else stained with different hues, and, in extreme cases, 
 has even a livid appearance: while, to a medical examination, it 
 is found to pit on pressure ; this condition often amounting to 
 absolute oedema, and the muscles being soft, yielding, and un- 
 elastic. Such persons have often the appearance of being fat ; 
 but this, when it exists, is wanting in firmness, as if a great part 
 of the accumulation consisted of water in the cellular membrane. 
 
MALARIA. 197 
 
 That varices and hernias should be common in the same circum- 
 stances, are facts which belong rather to the absolute diseases 
 that prevail in the marshy districts. It is also remarked that the 
 hair is flaccid and the beard scanty ; while, in the most poisonous 
 regions of France, it is further asserted that pale hair abounds, 
 when, in more healthy places, the very same race is noted for 
 the darker tints. A dull, languid eye, very often also yellow, is 
 a circumstance which has attracted general attention. 
 
 An enlargement of the abdomen, commencing sometimes even 
 from the birth, and often rendered the more conspicuous from the 
 slenderness and emaciation of the limbs, is also a feature which 
 no traveller has overlooked ; and it is often in itself sufficient to 
 demonstrate the nature of the place where these wretched beings 
 are doomed to live, or rather, as the inhabitants of the Pontine 
 marshes express it, to die. That the very form and extent of the 
 liver can often be traced externally, by the eye, is an anatomical 
 fact belonging to this state of things ; while an investigation after 
 death, discovers various diseased structures in that organ, in the 
 spleen, and in the mesenteric glands ; together with water in the 
 cellular membrane, and a general enlargement of the whole lym- 
 phatic system. In the Pontine marshes, the residents have the 
 appearance of walking spectres ; being often also oedematous all 
 over, and thus dragging on a miserable existence through the 
 short term of their wretched lives. That the inhabitants of such 
 districts have a late puberty and are less prolific than in healthier 
 regions, is a fact which has been asserted and again contra- 
 dicted : yet it is one which could not excite surprise should it be 
 proved. 
 
 There is nothing in these pernicious countries more striking to 
 a cursory traveller, than the appearance of age which occurs at a 
 very early period of life. Even the children are frequently 
 wrinkled ; and, in France, in perhaps all the worst districts, a 
 young woman, almost even before twenty, has the aspect of fifty ; 
 while, in men, the age of forty is equivalent to sixty in healthier 
 countries, both in appearance and vigour ; the very few who live 
 to fifty, appearing to have arrived at the protracted term of four- 
 score. Of personal beauty in females, there appears to be little 
 trace at any time ; but whatever may have existed is rarely pro- 
 longed beyond seventeen. And the expression keeps pace with 
 all else ; being that of unhappiness, stupidity, and apathy : an 
 habitual melancholy which nothing can rouse, and an insensibility 
 to almost every thing which operates on the feelings of mankind 
 in general. A slow and languid speech, a similar languor in the 
 walk and in all the actions, indicate equally the condition of the 
 mind and of the body in these wretched countries. 
 
 That the period between thirty-five and fifty is the most 
 
 B b 
 
198 DISEASES PRODUCED BY 
 
 hazardous and diseased portion of this diseased and miserable life, 
 is a very general remark in all the regions subject to Malaria ; 
 while it is not less generally observed, that those who survive 
 this period, often live to become old ; frequently also recovering 
 a certain portion of the health which might have been lost. Of 
 another general effect which has been asserted to exist, it seems 
 reasonable to entertain some doubts ; since it is an assured fact, 
 that a high degree of nervous irritability, both mental and bodily, 
 is a frequent attendant upon the chronic condition of the fevers 
 of Malaria. The assertion is, that the people in question are, 
 generally, little irritable, or even sensible ; and sometimes, to 
 such a degree, as scarcely to express the feelings of pain, even 
 under surgical operations. 
 
 The condition of the mental faculties, whether intellectual or 
 moral, is scarcely less remarkable, while it is more interesting : 
 and if there should appear any exaggeration as to some particu- 
 lars, or should any special fact, as asserted, depend on collateral 
 causes of another nature, the general bearing of the whole as re- 
 lated of Italy and France, has been confirmed too often byre- 
 marks of a similar nature, made in America and elsewhere by 
 very competent observers, to leave any doubt as to the leading 
 circumstances. 
 
 That apathy which was just noticed as expressed in the phy- 
 siognomy, is a character which influences the whole conduct of 
 these degraded and unfortunate beings ; often proceeding to such 
 a degree that they are scarcely elevated above the beasts in point 
 of feeling. Seeking solitude, shunning society and amusements 
 alike, without affections, without interest in anything, they make 
 no exertions to better their condition ; not even to avoid the 
 sources of danger which surround them, or to take the most com- 
 mon precautions that are pointed out : while, attached to the soil, 
 from habit or indolence rather than from regard, they will not be 
 convinced of its nature or dangers ; fatalists in practice and even 
 in belief, and refusing to admit that there is any other lot in life 
 than that which is their own. 
 
 That the general intellectual faculties are degraded, is an uni- 
 versal remark ; while, in many places, and very notedly in the 
 Maremma of Tuscany, it is observed that absolute idiotism is 
 common. That such a condition is a frequent result of marsh 
 fevers, and very particularly under improper treatment, is a fact 
 which I must notice in the medical part of this work : but even 
 independently of this, such debility of the intellect seems to be 
 the produce of the insensible action of this poison on the nervous 
 system: a circumstance that indeed might naturally be expected 
 from physiological considerations connected with the general in- 
 fluence which Malaria exerts on the body. And that this condi- 
 
MALARIA. 199 
 
 lion is even propagated, seems, further, fully proved ; so that an 
 universal degeneracy of mind and body both, appears to be the 
 certain lot of those races which a combination of unfortunate cir- 
 cumstances have placed in countries that seem to have been in- 
 tended rather for the habitations of reptiles and insects than for 
 those of man. 
 
 Considering that various glandular affections are the produce of 
 Malaria, it seems an object deserving of further inquiry, whether 
 that hitherto mysterious disease also, the Cretinage of the Valais, 
 may not possess some connection with the existence of this poi- 
 son ; since assuredly no explanation has yet been offered respect- 
 ing it. I cannot indeed find among the authors whom I have con- 
 sulted, any facts to confirm an opinion which is only offered as a 
 hint for inquiry ; and considering that analogous effects, as well as 
 many other diseases unattended by absolute marsh fever, are pro- 
 duced by the gradual action of Malaria, it is at least a subject de- 
 serving the attention of those who may have an opportunity of 
 investigating it, whether for confirmation or contradiction. It 
 is not impossible that those writers who have attributed the dis- 
 ease of the Valais to the peculiarity of its atmosphere rather than 
 to the other causes so often discussed, may have taken analogous 
 views to this : though it must still be obvious that the attachment 
 of the Goitre at least, to mountainous or hilly regions, all over the 
 world, is a difficulty from which we cannot easily extricate our- 
 selves. 
 
 Be the explanation of this latter disease however what it may, 
 it is an observation as old as physic itself, that inferiority of the 
 intellectual faculties is the inheritance of those who reside in 
 marshy countries, and in a dense, foggy atmosphere. If Hippo- 
 crates attributes to the effect of a salutary air, the very powers of 
 the intellect themselves, the well known proverb respecting Boe- 
 otian abilities was not probably without a foundation : while, 
 without apparently borrowing from Greece, a similar opinion has 
 not been less extensively entertained in our own days, and, I need 
 scarcely say, applied to Holland. 
 
 With respect to the moral condition of the people in those un- 
 healthy districts, the picture drawn by Monfalcon, is frightful ; 
 but as I cannot support it by sufficient evidence from other quar- 
 ters, it must rest on his credibility : while it must also be question- 
 ed how far moral and political circumstances unconnected with 
 disease or its cause, may be additional agents in the production of 
 these effects. Not to dwell on this disgusting picture, I must 
 content myself with naming abortion, infanticide, universal liber- 
 tinism, drunkenness, want of religion, gross superstitions, as the 
 leading features ; besides which, it is further said, and even proved 
 by the police reports, that while murders are common, a large 
 
200 DISEASES PRODUCED BY 
 
 proportion of the cases are those of premeditated and cautious 
 assassination, by poison or otherwise : all the vices, says my au- 
 thority, being of a mean and not of a bold character. But, while 
 averse to quotation, I am also desirous to refer to a work from 
 which I have been enabled to confirm many of the conclusions 
 which had long presented themselves to myself, and whence I 
 have recently derived a support which I had not found in the 
 Italian writers on this subject ; a statement of facts, as well as of 
 opinions or conclusions, which satisfies me that I had not misled 
 myself in those which were, not merely formed, but committed 
 to paper and made ready for publication, long before his book 
 came into my hands. Coincident opinions, thus independently 
 formed, carry with them a weight which cannot fail to strike 
 those who have attended to the nature of evidence. 
 
 Of the specific and definite diseases which are the produce of 
 Malaria, or which are endemic in marshy districts, some are now 
 notorious to the whole world, a few appear to me to deserve or 
 require the place which they have notj-et received, as its frequent 
 if not exclusive produce, and a few others must rest on the as- 
 sertions or testimony of the authors by whom they have been thus 
 enumerated. 
 
 Fever, continuous or remitting, of an endless diversity of cha- 
 racter indifferent countries and seasons, or, generally, in different 
 circumstances, stands prominent in this fearful list: itself the 
 source, either directly or through its consequences, of by far the 
 greatest mortality in such countries, and the further cause, as it 
 has been rudely computed, of more than half of the natural mor- 
 tality of the human race. To this may be added intermitting fe- 
 ver, not radically distinct, and almost equally various in its ap- 
 pearances : and those varieties, in both kinds, depending partly 
 on original or essential differences in the simple disease, and part- 
 ly on a combination with local or incidental and accessary effects, 
 which are often so conspicuous or important as to exceed in con- 
 sequence the radical disorder, or even to obscure it ; and, in some 
 instances, further, so completely, as to have been a source of se- 
 rious error. 
 
 Of these modifications, I could not here even give a catalogue 
 without medical descriptions in considerable detail ; scarcely ad- 
 missible in a work of this nature as far as it may become a sub- 
 ject of popular reading. I may only remark, that it comprises 
 numerous disorders, the real nature, as well as the causes of 
 which have been entirely, and almost universally, misapprehend- 
 ed in our own country ; though somewhat better known, yet still 
 but vaguely and partially to foreign physicians. And if, from be- 
 ing thus misunderstood, they have been maltreated, causing a vast 
 mass of suffering which might have been avoided or prevented, it 
 
MALARIA. 201 
 
 was the course of a long reflection on this subject, and an inves- 
 tigation of these diseases which were the primary inducements to 
 the production of the present work ; since but for this, even the 
 essay which I am now about to terminate, would never have been 
 written. 
 
 Dysentery, cholera, and diarrhoea may be here united as con- 
 stituting another division of the diseases of marshy countries ; 
 these disorders also appearing under different aspects, whether 
 from original differences or from combination. Of the vast im- 
 portance of these, it is superfluous to speak in detail. The mor- 
 tal power and extent of dysentery, in military service at least, is 
 but too well known. The influence of cholera concerns every 
 one : and if the cholera of India, lately so celebrated for its wide- 
 ly destructive effects, is, as I believe it to be, but a produce of 
 this cause, there are few diseases in the history of physic, which 
 would better deserve a place in this enumeration of those pesti- 
 lences which are the consequence of this wide-wasting poison. 
 
 The more serious incidents and consequences of these most 
 prominent disorders require also to be named ; especially as, 
 from their chronic character and their frequency, they constitute, 
 to an ordinary eye, the chief features of disease by which the 
 people in these unhappy countries are tormented and destroyed. 
 Apoplexy, palsy, visceral obstructions, and dropsy, under many 
 varieties, are the most prominent of these derangements ; but it is 
 the two last, and perhaps the visceral affections chiefly, which 
 excite the attention in those pestiferous regions, or rather, which 
 produce those effects on the appearance of the unfortunate inhab- 
 itants that have attracted every eye. This is the mark which is 
 stamped on those fated people, condemned to misery and death 
 through faults not their own : the beacon, which announces to 
 the traveller the lands of pestilence and mortality, which warns 
 him from the seductions by which Nature, through all her pro- 
 ductions but man, that only production " which dwindles there," 
 would tempt his curiosity or his stay. 
 
 But to those diseases many authors are inclined to add the me- 
 senteric affection, worms, ulcers of the legs, and even elephantia- 
 sis ; together with rickets, scrofula, phthisis, scurvy, and chloro- 
 sis. If the Pellagra of the Italian Alps is different from scurvy, 
 it will also require a place here ; but it may be questioned whe- 
 ther many of the disorders of this formidable catalogue are not 
 rather the results of a combination of circumstances easily conjec- 
 tured, than the proper consequences of marsh fever and dysente- 
 ry, or the produce of the direct action of Malaria. If, as has also 
 been said, the bronchocele is really the produce of the same re- 
 gions and causes, the hint which 1 have just suggested respecting 
 Cretinage may not be so questionable as it might appear at first 
 
202 DISEASES PRODUCED BY 
 
 sight. But respecting a disease which, personally unacquainted 
 with as an endemic, I cannot pretend to understand, I must ob- 
 serve that the authors whom I quote, distinguish the well known 
 Goitre of alpine countries from the one in question, which is con- 
 sidered of a different nature, and often of an acute character ; so 
 acute at times, and further, so epidemic, as, in some instances, to 
 have brought whole regiments to the hospital in the course of a 
 few days. The frequency of hernia and varix was formerly no- 
 ticed : and as far as the writers from whom I quote this mortal 
 catalogue can be depended on, 1 may conclude it with angina, 
 catarrh reaching to peripneumony, asthma, dyspepsia of an inve- 
 terate nature, and what is called oedema of the lungs. 
 
 Of very much of all this I have no personal knowledge : and I 
 do not think it necessary, nor perhaps proper, to offer such criti- 
 cisms on it as will be tolerably obvious to physicians ; but I have 
 a considerable addition to propose, in the disorders which I have 
 here ranked under the term neuralgia ; a list which, together with 
 its consequences, forming a great variety of diseases, it would be 
 impossible to give with any propriety, for the reasons already as- 
 signed in speaking of intermittent and remittent fevers. My med- 
 ical readers will probably seek it at the end of the subsequent vo- 
 lumes, where it was necessarily placed ; while for others, should 
 such there be, t^must here say a few words in explanation, that I 
 may not leave this account of the disorders produced by Malaria 
 so imperfect as it would otherwise be. 
 
 The Tic douloureux, to use the popular name, is well known 
 to be one of the most painful, as it is one of the most inveterate 
 diseases in the whole nosology ; the torment, often, of a long life, 
 and, too often, as incurable as tormenting, while, from whatever 
 causes, appearing to be increasing every day. An attention to 
 this subject for a very long course of years, has proved to me, 
 that, from whatever other causes it may sometimes arise, it is one 
 of the disorders produced by Malaria, and that moreover it is 
 very often a mode of intermittent fever ; a chronic disease of this 
 nature, attended by a peculiar local affection. 
 
 Further, under this leading disorder of the nervous system, the 
 same course of observation and experience has induced me to ar- 
 range a variety of painful affections formerly very differently con- 
 sidered, but of which a few have recently been thus classed : 
 hence causing me to constitute Neuralgia as a generic affection, 
 or a subgenus of intermittent, and the head of a very extensive 
 list of diseases, hitherto much misunderstood, and with conse- 
 quences which will be fully apparent in the medical portion of 
 this work. Such, not to enumerate the whole, are Sciatica, 
 Toothach, Headach, together with other affections, painful or 
 nervous, which have been often considered mysterious, and of 
 
MALARIA. 203 
 
 which the cure, like that of all the preceding, has consequently 
 been difficult or impossible. Thus also, and under evidence 
 which will be, as I trust, made satisfactory, it includes many in- 
 flammatory disorders ; chiefly chronic, which have been too often 
 the torment of patients and the opprobrium of physicians. And 
 if I have just noticed paralytic and apoplectic affections as apper- 
 taining to the diseases of Malaria, and in connexion with marsh 
 fever, they will also be found to be sequels of Neuralgia ; as are, 
 under various and peculiar circumstances, fatuity, and even mania. 
 
 Thus, then, Neuralgia, like intermittent or remittent fever, 
 takes a principal place in the disorders produced by Malaria, or 
 by marshes ; while it forms an entire and most important class, 
 the causes of which have hitherto been unknown, and comprises 
 numerous and serious diseases, of which even the generic charac- 
 ter has been unassigned, and the nature and treatment almost in- 
 variably mistaken. 
 
 These therefore form the last division of the disorders depen- 
 dent on Malaria; while entirely unnoticed as such by foreign or 
 former writers, even by those who have treated especially of this 
 subject. And if I could not therefore avoid pointing them out in 
 this place, I regret that I dare not here do more, and that I must 
 inevitably refer to the medical portion of these volumes for that 
 which forms so large a part of them. 1 shall only add, that if the 
 consideration of the neglected varieties of intermittent was a main 
 inducement to the production of this work, it was the study of 
 Neuralgia which originally led to the whole inquiry ; to that pri- 
 mary course of observation and reflection, of which the remain- 
 ing results will be submitted to the medical reader in the subse- 
 quent volumes. To proceed to another branch of this subject. 
 
 As dependent on this state of things, it will be interesting to 
 give a sketch, which can however be but brief and slender, of the 
 state of mortality in some of these unhealthy countries, as com- 
 pared with others : a subject which it would be a matter of no 
 small curiosity to investigate in greater detail than I can afford to 
 do in an essay of this nature. 
 
 It might perhaps be anticipated that under such circumstances 
 the population would gradually so diminish as to produce sensible 
 political consequences, or even to be exterminated altogether. 
 Thus it indeed certainly would, were it not for immigration ; 
 since, as will presently be seen, the deaths far exceed the births : 
 and in reality, in certain parts of Italy, if the inhabitants have not 
 literally been destroyed or exterminated, a partial result of this 
 kind, added to emigration or abandonment, has produced, as is 
 well known, the effect of absolute depopulation. 
 
 But in many places, and in the worst parts of France very con- 
 spicuously, the value of these lands for pasturage, for agriculture, 
 
201 DISEASES PRODUCED BY 
 
 or in fishing, affords a constant temptation to new and healthy 
 settlers, destined in no long time to run the same course, and 
 again to be replaced by fresh adventurers, to whom land or la- 
 bour is always open in consequence of the extraordinary mortali- 
 ty ; while the stupid and apathetic character of the fatalists by 
 whom such tracts are inhabited as their birth places, prevents 
 them from leaving a soil which they scarcely will believe to be 
 unwholesome ; thus giving the semblance of that blind attachment 
 to their native marshes, which poets, as blind, have lauded, as 
 poets use, and in other cases than this. 
 
 On this subject also, it is a preliminary remark worth making, 
 that no where are marriages more numerous, more blindly en- 
 tered on, and, very naturally, more frequently repeated ; since, 
 on the doctrine of chances, the condition of widowhood, on one 
 or the other side, cannot fail to be frequent. More women, it is 
 true, are re-married than men ; as, from obvious circumstances, 
 the mortality on the latter side is greater ; nor is it uncommon for 
 one woman to have had three, four, or even five husbands. On 
 the other hand, it has sometimes been known that one man has 
 married that number of wives : the tale being told in Bresse (if I 
 am not mistaken) of three brothers who had married, between 
 them, fifteen women. This system of survivorship, however the 
 balance may lie, is explained by the fact, that the polygamous in- 
 dividual is commonly a native of the country, and the mortal as- 
 sociates immigrants from healthier districts : and thus has it been 
 said, not only in France, but among ourselves in Lincolnshire, 
 that speculators on such survivorship choose their partners from 
 the healthy neighbouring lands, and thus, of either sex, often ac- 
 cumulate the fortunes of successive victims. In addition to the 
 natural temptations arising from vacancy, whether of wives, hus- 
 bands, farms, or labour, I need scarcely perhaps remark, that such 
 marriages are often, in addition, the result, not merely of a pre- 
 vailing libertinism belonging to the depravity of the moral charac- 
 ter and the fatalism of these countries, but of that recklessness 
 which is so noted an attendant of poverty everywhere, and very 
 familiarly, in Ireland ; and which, in circumstances, analogous, 
 though far from parallel, leads the seaman over whom death is 
 impending from the surrounding rocks, to plunder and forget him- 
 self in intoxication. 
 
 If the few statements which I can here afford to give respect- 
 ing the mortality in question, are apparently at variance, it is 
 chiefly perhaps because that varies itself, materially, in different 
 places ; while some have derived their results from one country 
 or district, and some from another. For the present purpose, it 
 is unnecessary to be accurate or critical ; and a few remarks of 
 this nature will suffice. Whoever desires to know fully these 
 
MALARIA. 205 
 
 computations and their grounds, can easily refer to the authors 
 whom T have here quoted, and to many others whose names are 
 familiar to those acquainted with political arithmetic. 
 
 The mean annual mortality in these cases, as computed by Dr. 
 Price, gives an average of twenty-five years of life, founded cer- 
 tainly not on the most unfavourable facts ; while Condorcet, 
 from other, and apparently worse situations, places it as low as 
 eighteen : a conclusion in which some exaggeration may be sus- 
 pected, unless he has selected some peculiarly unfavourable case. 
 In Bresse in the Lyonnais, it has been computed as varying from 
 twenty to twenty-two. These are examples enough, perhaps ; 
 and it will be remembered that a mean term of life in the coun- 
 tries of Europe not subject to the plague of Malaria, is found to 
 extend from forty-five, upwards, to a period, as to our own coun- 
 try, which has now, and assuredly had for some time past, ex- 
 tended to a considerably higher average. 
 
 With respect to the extreme term of individual life in such ca- 
 ses, it is stated by many writers, that in Egypt, and in Georgia 
 and Virginia, in all the marshy situations, it does not exceed forty; 
 exceptions being of course understood for specific cases : while 
 Jackson asserts that at Petersburg!! in the latter province, a 
 native and inhabitant rarely obtains the age of twenty-one. In 
 France, Rozier places this extreme limit, for those portions of 
 Britany which adjoin the Loire, at fifty ; at which age the indi- 
 vidual wfertK has escaped thus long, equals a man of eighty in 
 healthier countries. In various parts of Italy, Sicily, Sardinia, 
 Corsica, Wallachia, Moldavia, Hungary, life, whether computed 
 in this last or in the preceding manner, presents a still more un- 
 favourable aspect ; though perhaps under the circumstances of 
 misery beneath which this burden is borne, that shortness is a 
 blessing rather than an evil. But not to protract this manner of 
 contemplating so fearful a picture, I may now place the same 
 facts in a different light, that travellers who may interest them- 
 selves in this question, may see how, under one or other of these 
 modes, they may direct their inquiries. 
 
 In the Commune of Chatillon, (Orleannais,) in ten years, there 
 were 1845 births, and 2046 deaths; or the annual average was 
 184 of the former to 204 of the latter nearly : giving an unfavour- 
 able proportion of nearly one to five. This is an example of a 
 very unhealthy district, though far inferior, still, to many parts of 
 the countries which I have named above ; and if the general pro- 
 bability of deaths is taken at 28 in 1000, it rises here to 51. Si- 
 milarly, in Brenne (Berri,) Sologne (Orleannais,) and Bresse 
 (Lyonnais,) the deaths far exceed the births ; though Monfalcon, 
 from whom I have borrowed this general fact, has not given the 
 calculations. In the latter district, however, the registry shows 
 
 C c 
 
206 DISEASES PRODUCED BY 
 
 that the term of individual life, considered as longevity, ranges 
 from thirty-five to fifty ; while the survivorships at this latter limit 
 are very few, as it is, there, extreme and rare old age. How all 
 these proportions stand in the Maremma of Tuscany, in the neigh- 
 bourhood of Rome, on the Calabrian coast, in the Mantuan, at 
 Syracuse, and in many other parts of Italy and Sicily now fami- 
 liar to so many of our countrymen, I need not say, as they are 
 generally known to all who have had any communication with 
 those regions. 
 
 A few further facts, from the unhealthy tracts of France, rest- 
 ing on the authority quoted above, will complete all that I dare 
 take room for in this sketch ; while by placing in these several 
 lights the effects of the Malaria, the extreme importance of the 
 whole question will become more obvious to those who, living in 
 comparative security, are commonly as incredulous and ignorant 
 as they are thankless for the better lot which they have not so ex- 
 clusively merited. 
 
 In spite of immigration, as well as of a rise in the value of lands, 
 the population of Sologne (Orleannais,) has diminished two-thirds 
 in the space of a century and a half. The town of Villars in Bur- 
 gundy, within a century, has been reduced from eight hundred 
 houses to a wretched line of a few cottages ; and the same kind 
 of reduction has taken place in many other towns and villages in 
 this most miserable country. In ten communes, the diminution 
 has been one-eighth in twenty-two years, while the general wealth, 
 agriculture, and population of France at large have been under- 
 going a rapid and marked increase. 
 
 I might easily have extended this particular set of facts by simi- 
 lar notices as to many other portions of the same country, so little 
 suspected hitherto by English emigrants ; or rather, I may say,. 
 so little suspected even to this hour, that the catalogue of their 
 sufferings from that cause, from a rash choice of residence chiefly, 
 would in itself make a formidable appearance. I might equally 
 point out the similar diminutions, often the absolute extermina- 
 tion or abandonment, of many portions of Italy : but these are so 
 well known to every one who has even the most common read- 
 ing respecting that unfortunate country, that it would be merely 
 to repeat what all the world knows ; while also, in other places 
 and for other purposes, I have had occasion to allude to those 
 facts, and, very particularly, to describe the singular and fearful 
 condition of Rome. 
 
 I will therefore terminate this very brief sketch of the general 
 effects of Malaria on the residents in marshy or unhealthy regions ; 
 a subject which might well be extended to twenty 'times the 
 length, with instruction perhaps, for which my plan allows me no 
 room, and with amusement, I doubt not, in which I must not in- 
 
MALARIA. 207 
 
 dulge. This short notice will have answered its purpose if it shall 
 assist in enlightening or convincing the ignorant and incredulous; 
 in holding up to their eyes the great enemy of the human race, 
 the very Destroying Angel to whom the task of keeping man 
 within due hounds has been especially assigned ; if it shall con- 
 vince them that the subject which I have here brought before 
 them is worthy of their knowledge, inasmuch as they are not, 
 even in this more fortunate island, exempt from danger and from 
 mortality through this cause, and inasmuch as it is in their power, 
 by care founded on that knowledge, to diminish or avert the evils 
 which it produces among ourselves, and, however little that may 
 at present be suspected, in no small proportion. 
 
 It may be thought a question of mere curiosity whether other 
 animals than man can be affected by Malaria, or suffer diseases 
 analogous to those which it produces in us : but the solution of 
 any question of this nature is valuable, since we can never foresee 
 what light may not be thrown on physic as a science, from facts 
 as relating to the diseases of the inferior tribes. It is to France 
 and Italy chiefly that we owe what information there is on this 
 subject ; since, like every thing else appertaining to the history 
 and effects of Malaria, it has been neglected in England; though 
 I must make one exception at least in favour of Mr. Royston, who 
 alone seems to have been led to make the same remarks in Cam- 
 bridgeshire. The general fact is, that cattle, or animals of differ- 
 ent kinds, do become sickly or diseased in the same situations 
 which produce the diseases of Malaria in the human race, and 
 that the consequences are as resembling or analogous as they 
 could be under the differences which exist. 
 
 On this subject, and as it relates to Italy, Lancisi is one of the 
 strongest as of the earliest authorities. He remarks, as many 
 others have also done, that in the Roman states, in marshy places 
 and in summer, epidemics, or epizootics, are common among the 
 cattle ; and though the descriptions of the diseases are not very 
 satisfactory, the dissections, by his account, display exactly the 
 same appearances as are observed in men who die of marsh fe- 
 vers. This fact, of the appearances on dissection, has been con- 
 firmed by various observers in the Milanese ; and also in Egypt, 
 in Hungary, in St. Domingo and Gaudaloupe, as well as in 
 France, at Rochelle, and in Auvergne and Roussillion. The 
 connection between seasons of peculiarly severe epidemic marsh 
 fevers in man, and of epizootics in cattle, is particularly pointed 
 out by Bailly, of the year 1812 at Aries; and in this instance, the 
 inflammatory affections and the subsequent disorganizations proved 
 to be the same in the animals as in the people dying of the fever. 
 
 Analogous observations have been frequently made in Italy : 
 and not to quote more than is necessary, the years 1711, 1738, 
 
208 DISEASES PRODUCED BY 
 
 1745, 1772, 1783, and 1795, are among those which have been 
 particularly recorded for epizootics among cattle ; each of them 
 being also noted seasons of epidemic fever, or of the prevalence 
 of Malaria. Further, they all occurred in the months of August, 
 September, and October, and were also confined to the marshy 
 or unhealthy districts ; while it was in addition remarked, that 
 the cattle introduced from the hilly and healthy countries were 
 those that suffered most, as men are known to do under similar 
 circumstances, and that, very particularly, those oxen were most 
 frequently and severely affected which had been employed in 
 ploughing up the pasture lands ; an operation which, as I have 
 remarked in another place, is generally dangerous to the human 
 race, disengaging, or giving rise to the production of Malaria. 
 
 The fever or plague of black cattle, not uncommon in certain 
 parts of France, if rare with us, is attributed very generally, by 
 the veterinarians of that country, to Malaria ; and of remarkable 
 instances of this nature, one is noticed by Chaignebrun, occurring 
 in summer, in a marshy tract in the forest of Crecy, which des- 
 troyed about three-fifths of the cattle attacked ; the number of the 
 last being nearly 500, and the disease being described as a typhus 
 with effusions into the thorax and abdomen. A similar fact is re- 
 lated by Petit, of Auvergne ; and it is remarked by Guersent, that 
 all the fevers of this nature occur in summer and in marshy situa- 
 tions. In other districts, a similar fever in cattle has been found 
 attended by inflammations of the lungs, and in horses, of the throat; 
 while dropsy, probably from a previous fever of the same nature, 
 is common in sheep. These latter animals are said to be subject, 
 in the Orleannais, in the department of the Loire and Cher, al- 
 ready quoted as one of the most pestiferous tracts in France, to 
 such frequent epizootics, that it is necessary to renew the races 
 every ten year, while they degenerate from the moment of their 
 introduction, and present at all times a miserable appearance. 
 
 To such a cause we may also probably refer the asthenia ossi- 
 fraga, as it was called by Paulli, occurring among sheep in Smo- 
 land, and by him attributed to their eating the Anthericum (Nar- 
 thecium) ossifragum ; though Linnasus has rejected the whole as 
 a popular tale. I need not say to botanists that this is a native of 
 marshy soils, and that the general views here held out will pro- 
 bably explain, in a similar manner, the popular opinion of the pro- 
 duction of diseases in the same animals from feeding on the Hy- 
 drocotyle vulgaris ; a plant which, it so happens, they will not 
 eat 
 
 Independently of absolute fevers and death, the general health 
 of the cattle and sheep in all these marshy districts seems to suffer 
 in a manner analogous to what it does in men ; nor can that be 
 ascribed to want of food, nor even to improper food ; as the pas- 
 
MALARIA. 209 
 
 toral, and very often the agricultural value of these poisonous dis- 
 tricts is considerable, often indeed temptingly high. In Brenne, 
 (Bas Berry,) the cattle are weak, stunted, dull, and, as it is said 
 ricketty ; while it is remarked that they are subject to a chronic 
 state of fever, attended with a slight inflammatory condition of the 
 bowels and lungs. In the Orleannais, black cattle are difficult to 
 rear, and are stunted in their growth, degenerating, like sheep, in 
 the first generation ; and this is remarked of other places, by 
 Bosc, both with regard to cattle and horses, though the latter 
 animal seems to offer greater powers of resistance to the poison, 
 thriving often where sheep die. It is also remarked that in such 
 districts, the animals in question, and the sheep in particular, are 
 less prolific. It is further observed in France generally, that the 
 flesh of animals in such situations is bad, or flavourless and wa- 
 tery ; and this fact is confirmed by what occurred in Sicily, well 
 known to our armies when occupying that island ; namely, that 
 the beef was similarly bad if procured in the country, but when 
 the Sicilian cattle were transported to Malta for a few months, it 
 became excellent. 
 
 Such are the facts best ascertained as to the influence of Malaria 
 on the agricultural animals ; and they seem to leave little doubt 
 that its action on them is similar to what it is on the human race, 
 as far at least as relates to the production of continuous, or remit- 
 tent, and autumnal fever, with the usual topical acute affections 
 and chronic consequences : to which we may probably add a 
 chronic fever, with, not improperly, obscure or tedious disorgani- 
 zation, or deterioration of functions, similar also to what happens 
 in man; productive of degeneracy and general ill health. If it 
 has been said that geese suffer from feeding in noxious marshes, 
 and that the disorder in this case is an enlargement of the liver, 
 the fact, if true, will present another interesting analogy ; but I am 
 not sufficiently satisfied with the evidence, to lay any stress on it. 
 The curious in eating may inquire whether the celebrity of the 
 livers of the Ravenna geese in ancient times was connected with 
 this fact : if indeed it be a fact. 
 
 This, as far as relates to the kinds of animals affected by Ma- 
 laria, seems to be the sum of what is generally known ; but I have 
 received information of a similar nature from the West Indies, re- 
 specting another animal, so decided as to the asserted fact, and 
 from so many different sources, that there seems no reason to 
 doubt, either the mere truth or its accuracy. It is, that immedi- 
 ately before the season of fevers, the dogs become diseased, as 
 from a fever, or that the epidemic appears in them before it is 
 established among the people : and further, that a season of dis- 
 ease of unusual severity is always expected, in Dominica particu- 
 larly, whenever the sickness and mortality among the dogs is un- 
 
210 DISEASES PRODUCED BY 
 
 usually great. I have obtained no specific account of the nature 
 of this fever, though it may be conjectured that it is a continuous 
 one, like that which, in the same circumstances, commits such 
 ravages on cattle. But I cannot persuade myself to omit one case 
 of the occurrence of a regular tertian intermittent in a dog, be- 
 cause I cannot doubt the medical testimony on which it rests, par- 
 ticularly as the persons in question had no interest in the fact : a 
 suspicion which might easily attach to a writer on such a subject. 
 He who relates simply the conviction of others, removes at least 
 from himself, the claim to credibility. The surgeons in question 
 were those of the island of Guernsey, to whom the animal was 
 submitted for examination ; and as the disease continued for some 
 years, the cold paroxysm taking place always at three o'clock, 
 there was ample opportunity of verification. 
 
 If this case confirms the observations of Mr. Royston as to the 
 occurrence of true intermittents in the agricultural animals, so is 
 it confirmed by those very interesting remarks ; and it is not im- 
 probable that if more attention were paid to this subject, if there 
 were more such observers, intermittent would be found not an 
 uncommon epizootic, or endemic in cattle, confirming the ana- 
 logy already pointed out in the case of autumnal remittent or 
 continuous fever. 
 
 On this subject also it'is not unworthy of observation, that the 
 remarkable disease of the liver in sheep, commonly called the 
 rot, is the produce of wet lands, and very pointedly, in Lincoln- 
 shire, of those fen lands which also generate Malaria : while it 
 does not occur in dry situations, and is, further, cured by remov- 
 ing the diseased animals to such places. In France it is believed 
 to be the produce of the Malaria of marshy lands ; though it may 
 be too much to say that the rot is a disorder so produced in all 
 cases ; but while considerable ignorance exists as to its true na- 
 ture or causes, and while the different ones which have been as- 
 signed for it are either trifling or unfounded, there is at least 
 nothing to oppose to such a supposition, and the question remains 
 open to enquiry. It is far from impossible that the poisonous 
 atmosphere which acts on man in producing so many diseases, 
 should also act similarly on animals ; on the contrary, we should 
 have decided that this was a general probability, had not experi- 
 ence shown how many inheritances of this nature man possesses 
 to their exclusion. But as there is no law which rules that man 
 and animals shall not have a common disease, and as there are 
 instances in abundance of the reverse, we are far from having 
 any right to assume, that, in the instance alluded to, that poison 
 which acts so widely and severely on man, shall not also exert a 
 corresponding, or possibly a different, but a morbid action, on 
 some one or more of the inferior animals. With respect indeed 
 
MALARIA. 211 
 
 both to this disease and to the fevers of black cattle, I am the 
 more confirmed in the opinions here stated, from the answers to 
 some inquiries which I have recently made in Lincolnshire. The 
 general fact as stated in those is, that the several disorders here 
 noticed used to be very common before the drainage of the fens, 
 but that they are now scarcely known ; and how important there- 
 fore the knowledge of Malaria must be, even in rural economy, 
 is too obvious to require another word. 
 
 But to the disgrace of physic as of rural economy, to the dis- 
 grace indeed of public economy and of an enlightened and busy 
 age, the diseases of animals are almost utterly unknown, as dis- 
 eases should be known, with some slender exceptions as to the 
 horse ; while, independantly of the merely economical question 
 in this case, the very extraordinary epizootics which have been 
 noticed at different times form a most interesting object of scien- 
 tific inquiry. These sweeping disorders, sometimes possibly 
 proving the production of contagion, assuredly prove at least the 
 production of what must be called a Malaria, for want of another 
 term ; since, if we except the case of food, that is of noxious food 
 or of deficiency, on no other principle that we can conceive, but 
 that of an atmospheric and respired poison, can an epidemic or 
 epizootic exist ; the case also of casually abounding inflamations 
 being of course excepted. And ff such is the general cause, it 
 remains to be investigated whether such Malarias are produced 
 from land, like our own, and how ; and whether also that very 
 species which to us is so poisonous, may not, under particular 
 circumstances, operate equally on some or other of the inferior 
 animals, though with results as to the form of the disease, of a 
 different nature. 
 
 It would be out of place however to pursue this very remark- 
 able and much neglected subject of Epizootics ; though even as it 
 relates to the wild animals, it interests us in an economical view : 
 seeing that it is a probably assisting cause, as well as inequality 
 of reproduction, in the frequent disappearance or diminution of 
 particular species, in the sea as well as on the land ; a fact in 
 which we are often deeply concerned. That such diseases have 
 occurred, and sometimes indeed have been frequently repeated, 
 even within recent recollection, in cattle, horses, sheep, cats, 
 bees, leeches, dogs, and more, is sufficient to show how much 
 they concern us ; and that I have, in my own narrow observa- 
 tion, found that extensive epizootics or seasons of extraordinary 
 mortality have occurred in seals, in whitings, and I think in some 
 other fishes, and in sea-gulls, (the kittiwake,) while it is a proof 
 of their extent in the animal kingdom, may also serve to explain 
 many of those revolutions in the numbers of peculiar species, 
 even in fishes, of which we have long been amply sensible in the 
 
212 DISEASES PRODUCED BY 
 
 results, without considering the causes ; as it may also probably 
 aid in explaining similar and far more noted revolutions in the in- 
 sect tribes, often of even more importance to us than changes in 
 the distribution or numbers of the more obvious or larger ani- 
 mals. But as I must not here pursue this subject, I shall content 
 myself with suggesting, that while the study of these animal dis- 
 eases is, in itself and abstractedly, most necessary, it is not im- 
 possible that a future acquaintance with them and with their 
 causes, may tend in time to throw light on Malaria as it affects 
 us, even should our own Malaria, if T may so call it, be a dis- 
 tinct variety, incapable of acting on any animal but man. 
 
 But there is one circumstance on which I must here insist, be- 
 fore I conclude this essay, and with which I shall terminate what 
 I have to offer on Malaria, or rather, what 1 think sufficient for 
 the purposes which I had in view ; utility : the prevention, and, 
 in some measure, the cure also of disease. It is true that I have 
 had occasion to touch on it more than once ; but I consider it 
 too important not to be brought fully and fairly before the reader, 
 that he may at least bestow his own careful consideration on it, 
 though he should not choose to agree with me. It is, in reality, 
 of the greatest importance, because a great portion of the entire 
 question as to Malaria rests on it ; that is, in as far as we propose 
 to turn our knowledge to purposes of utility, whether as to the 
 prevention of the diseases originating in this cause, or their cure. 
 
 If, of an effect, or of many effects, there is but one cause, we 
 have attained a mastery by knowing that, which becomes mate- 
 rially reduced in value should there be more than one ; while 
 should we even suspect additional causes that we cannot prove, 
 there is excited a want of confidence in our philosophical princi- 
 ples, which materially interferes with the results that we might 
 otherwise have derived from them. It is therefore most essential 
 to ascertain, if that indeed be possible, that the various diseases 
 attributed to Malaria are really produced by that cause and by 
 no other; or that, being an unquestioned cause of the fevers 
 which occur in certain situations, it is also the sole one. 
 
 I need scarcely commence by saying that he who desires to 
 prove this, has undertaken a task which is not merely difficult, 
 but, in a strict sense, impracticable : not only because to prove a 
 negative is almost always an insurmountable difficulty in the less 
 accurate sciences, but because there are to be encountered preju- 
 dices and habits, as firmly as they are anciently rooted ; and not 
 the less inveterately subjects of belief that they are utterly void 
 of demonstration, or even of proofs of the lowest order. In defi- 
 ciency therefore of direct evidence or demonstration, there is no 
 resource but to approximate the facts in a simple and logical or- 
 der, and to trust their effect to those whose philosophical habits 
 
MALARIA. 213 
 
 empower them to weigh moral probabilities ; since, of that na- 
 ture, must the present exposition consist. 
 
 It is amply demonstrated in the first place, that the fevers in 
 question are caused by exposure to the atmosphere of marshy 
 grounds, or to what is here called Malaria ; so that, respecting 
 the reality of this cause there is no doubt. But physicians have 
 been in the habit of asserting that they are also caused by heat 
 simply, or by heat and moisture, or by cold under the same vari- 
 eties ; or by fatigue, errors or deficiency of diet, the passions of 
 the mind, and other causes which I need not name, inducing 
 what they term debility. 
 
 Now, to pass over the well known maxim in philosophy, that 
 superfluous causes ought not to be assumed, let us first remark, 
 that the period during which these last named or unproved causes 
 were assumed, was that period of medical and philosophical ig- 
 norance in which the very existence of the chemical substance 
 called Malaria was unsuspected, and when, as I showed in the 
 last chapter, the effects of marshes in producing disease were at- 
 tributed to defective elasticity in the air, to animalcule, to heat, 
 putrefaction, or whatever else there was of vague, fanciful, or un- 
 meaning, which constituted the medical and philosophical lan- 
 guage, not reasoning, of that day, and which still forms the far 
 better part of the whole philosophy of physic. 
 
 Let us remark in the next place, that the unproved causes in 
 question have been equally applied by physic, and from the ear- 
 liest and darkest periods, as in the present day, to the explanation 
 of numerous other diseases, perhaps of nearly all the important 
 ones, and to diseases of the most opposite character to those un- 
 der review. And I should not say what is untrue were I to say, 
 that these have been used, and still are used most commonly, as 
 a mere string of terms, without waiting to consider of their mean- 
 ing or application : that they are a part of that phraseology which 
 constitutes what is considered as philosophy in physic, and which 
 forms, under other modes, the far better part also of the ordinary 
 —reasoning as it is usually termed, in the several branches of 
 morals. 
 
 It is somewhat, in such a case as this, to trace the origin and 
 character of opinions, because we may thus often shake the 
 structure which we cannot directly demolish. Let us next see 
 what the probabilities are, that these causes do produce the sup- 
 posed effects. 
 
 If in respect to the production of disease, a single cause were 
 always sufficient, or always the sole agent, there would be no dif- 
 ficulty in proving that not one of these is the cause of marsh fe- 
 vers ; but unfortunately it happens that the state of the subject of 
 action is too often implicated in the effect, or that two causes or 
 
 D d 
 
214 DISEASES PRODUCED BY 
 
 sets of causes must concur to its production. These, respective- 
 ly, are the exciting and the predisposing causes of physic ; or the 
 real cause, and the opportunity afforded for its action ; and if 
 there may sometimes be a difficulty in allotting them, the more 
 common event is, that as the latter are commonly palpable, and 
 the true cause difficult to discover, physic contents itself with 
 what is most easy, and thus wanders about among those errors 
 of which the present case is, I doubt not, an example, 
 
 "We must therefore try this question in another way, and at- 
 tempt to deduce out of a broad mass of facts, that conclusion 
 which could not be derived from individual and separate ones ; 
 and if this can be done, the point is proved, because it is thus in 
 reality that even accurate philosophy must in most cases arrive 
 at truth. If it can be shown that the one cause here assumed as 
 the true and sole one, acts as often as it is fully called into action, 
 and that the power of the others is irregular and uncertain, still 
 more that there are regular and constant circumstances under 
 which they never do act, and further, that when they seem to 
 act, the real cause is also present or probably present, then does 
 it appear to me that the point will be proved as far as any thing 
 ever can be proved in those sciences which do not admit of math- 
 ematical demonstration. 
 
 Now it may safely be asserted in the first place, that the seve- 
 ral unproved causes in question, which I need not again enume- 
 rate, exist at all times of the year, and secondly, that they exist 
 in all the countries of the world. Or, to be more minute, and to 
 divide them into two classes, those which belong to man himself, 
 such as fatigue, injurious passions, diet, or other causes of debili- 
 ty, are found equally distributed, on a broad average, throughout 
 mankind, everywhere, in all climates, and at all seasons of the 
 year ; while injurious conditions of temperature, if less amenable 
 to the same average, occur under rules that offer certain avera- 
 ges also, but which are distinct from those that regulate the exis- 
 tence of the one, and the as yet only proved cause, Malaria. 
 
 Now were the first division of these causes the real causes of 
 such fever, it should bear an equal or analogous average through- 
 out mankind, which, I have fully shown, it does not. These hu- 
 man causes, as I may call them for the sake of distinction, can- 
 not therefore be the causes of such fever, because they do not 
 possess the necessary philosophical qualities ; and I may there- 
 fore dismiss them . 
 
 With respect to the second division, or the assumed causes, 
 consisting in temperature, the statement of facts must be some- 
 what longer, because in the usual lax language of physic, the 
 whole of the circumstances are promiscuously enumerated, and 
 without the requisite discrimination; insomuch that were they 
 
MALARIA. 215 
 
 really causes of fever, it would be difficult to see how any person 
 should escape ; or rather, the whole world, in certain climates, 
 or in all climates, would stand on an equal average, or on certain 
 distinct averages, with regard to these diseases : which it does 
 not. 
 
 To distinguish ; the operations of temperature must consist in 
 continuous cold, or that which is beneath a low mean heat, to be 
 safely enough taken at 40°, or in continuous heat, or that which 
 is above a high mean, which may be as safely fixed at 65° ; or 
 else it must depend on transitions from a high to a low tempera- 
 ture, or the reverse. The partial operation of cold is not worth 
 distinguishing in this case ; and with respect to moisture, it seems 
 agreed that its influence is dependent on its relations to tempera- 
 ture. But should it be esteemed a separate cause, it must be dis- 
 tinguished into excess and defect : and thus the whole question 
 as to these causes is cleared for examination. 
 
 Now, that continuous cold does not produce marsh fever, is 
 proved, partly because that does not occur in cold climates or in 
 cold seasons ; very particularly because it does not happen in 
 winter, even in those places where the proved cause, Malaria, is 
 present, or where at least it would exist if the temperature per- 
 mitted its production. That continuous heat alone does not pro- 
 duce this fever, is proved, because it is not generated in the dry 
 or sandy tropical climates, where the heat is often more extreme 
 than even in those of a different character. And that neither 
 transitions from cold to heat nor from heat to cold do alone pro- 
 duce it, is proved, because the former set of transitions occur, as 
 they must, in every cold climate, and in some very notedly, on 
 the coming on of spring, yet without producing fevers ; while the 
 reverse case, or the transition from heat to cold is, even more no- 
 toriously, not simply common, but a daily occurrence, in the 
 burning sandy deserts, where hot days are followed by cold nights, 
 and where, still, fever is not the consequence. 
 
 Thus these causes of fever also may be safely elicited out of the 
 enumeration, if reasoning from facts is of any value, if there is any 
 case where the generalizations of philosophy are admitted as de- 
 serving of regard. 
 
 Now, lastly, with respect to moisture, admitting it as including 
 a separate set of causes, we may first, I believe, safely neglect de- 
 fect of moisture, otherwise than as it acts in producing cold by 
 accelerating evaporation, and as coming therefore under the for- 
 mer case, since it has not been supposed a cause of fever. With 
 regard to moisture in excess, whether we leave out the case or 
 not of its producing cold by its conducting power, (though I for- 
 merly examined that subject in treating of the east wind,) I must 
 partly repeat here, that if it could produce fever by itself, a fog 
 
216 DISEASES PRODUCED BY 
 
 from whatever quarter would be a cause of disease, or an equal 
 cause ; that the fogs or clouds of elevated or mountainous regions 
 would produce fever ; that this would occur equally in all moist 
 countries, of whatever temperature ; that the western Highlands 
 or Cornwall, for example, in our own island, would be more sub- 
 ject to fevers than Norfolk or Lincolnshire ; and that, at sea in 
 particular, they should be unusually common. Not to examine 
 separately these cases, it will be sufficient to say that they are no- 
 toriously not the causes of such disease, and that at sea, very re- 
 markably, other causes being elicited, fevers are almost unknown. 
 How Malaria is produced in a ship, I formerly explained. 
 
 Thus have I gone through the whole of the reputed but un- 
 proved causes of fevers, or rather of remittent fever, since I must 
 shortly proceed to a medical discriminating remark on this term : 
 and I must think that had I been discussing a question in any 
 other branch of philosophy than physic, I should have proved my 
 case to the satisfaction of every reasoning mind : proved that not 
 one of these causes was the real cause, or the " exciting cause" 
 of this fever, whatever share they may take in operating on the 
 body so as to render it capable of being influenced by the real 
 cause. But I know physic too well to expect that I shall pro- 
 duce such conviction ; since against what is neither logic nor phi- 
 losophy, philosophy and logic are opposed in vain. 
 
 Let me now attempt to show whence the fallacy arises ; while 
 on that I may be brief, since it is but a recapitulation of much 
 that has already been proved. 
 
 Fevers abound in certain climates, places, and seasons, where 
 vegetable decomposition proceeds in a rapid or peculiar manner, 
 and they are proved to be produced by exposure to the atmos- 
 phere of those places, which is concluded therefore to involve an 
 unknown gaseous substance called Malaria. The causes produc- 
 tive of Malaria being demonstrated, such fevers are proportioned 
 in number and severity to the power of these causes, increasing 
 as they increase, diminishing when they diminish, and when they 
 disappear, disappearing. Malaria therefore, however unknown 
 it may be, possesses all the philosophical properties of a cause ; 
 and as I have shown that fevers are not produced where it is not 
 present, though all the other presumed causes are so, these can- 
 not be Causes. 
 
 The fallacy is plain ; that is, supposing these causes to have 
 been really assigned from presumed observation, and not the mere 
 phraseology which 1 believe to have been the case. As the causes 
 here called human ones must exist everywhere and at all times, 
 they must be in existence where the real cause, Malaria, is in ac- 
 tion. The same is true respecting heat, injurious vacillations of 
 temperature, and moisture : while these, in particular, are causes 
 
MALARIA. 217 
 
 which bring Malaria into action or tend to produce it. These 
 therefore are either concatenated incidents, or causes of Malaria, 
 or of its action ; the causes of the true cause, not those of the 
 effect. 
 
 I must leave this train of argument to produce such impression 
 as may be its fate, while I cannot see how it is to be answered : 
 and I need not repeat that the circumstances which I have now 
 attempted to elicit as real causes, may perhaps be allowed to be 
 predisposing ones : actions which are incapable, by themselves, 
 of determinating this particular effect, while they aid in the pro- 
 duction of many others, even of the most opposite nature. 
 
 On these, as predisposing causes, I need not here dwell ; the 
 more, that it is peculiarly a medical subject, and does not, in 
 strictness, belong to the matter in hand. In as far as they may 
 act in modifying the character of the diseases produced by Mala- 
 ria, I have already shewn that it is very doubtful if they do so act. 
 It is a point which, in any view, requires to be investigated, and 
 really investigated : since it is quite time that physic should cease 
 to assert, and commence to prove : that it should re-examine what 
 it has hitherto believed, together with its grounds of belief, and 
 not be content, in these days of a better philosophy, with its an- 
 cient dogmas ; with that which it believes and acts on from habit, 
 not from conviction, and with the phraseology which it too often 
 mistakes for reasoning. 
 
 In how far the circumstances in question predispose to disease 
 at all, is matter for experience rather than for reasoning ; since 
 we do not know in what that predisposing action consists. That 
 is, we do not know, truly and phisiologically, how the cause 
 acts, nor what are its effects. Generally, it seems proved by ex- 
 perience, that if the body is in an unusual state of muscular 
 weakness, or beneath its average standard of strength, the facility 
 of acquiring certain diseases, and fevers among others, from ap- 
 plication of the exciting cause, is increased; and thus has it been 
 said that debility, or causes inducing debility, are predisposing 
 causes. This, however, is but phraseology ; it leaves us where 
 we were before : while in the case of the predisposing, or pre- 
 sumed predisposing causes in question, it remains to be shewn 
 in what manner many of them produce debility, or whether 
 they produce it at all. That many of them do not induce sensi- 
 ble muscular debility, is certain ; and that this may be present, 
 from numerous causes, without nevertheless leading to disease, 
 is no less certain. Thus it must be feared that we are still in 
 darkness ; compelled to rest on certain experienced facts, but 
 unable to determine their nature or their action : and, as far as 
 we use these terms, using them without being able to assign their 
 meaning, or explain our own. 
 
218 DISEASES PRODUCED BY 
 
 To complete this discussion however as to purposes of utility, 
 I must repeat briefly what I hope I have formerly proved ; that 
 the sources of Malaria are far more widely diffused than has gene- 
 rally been supposed, that they can often be truly proved to have 
 been the causes ot fever when that has been attributed to fal- 
 lacious or imaginary ones, and that this poison is probably always 
 the real cause of the disorders under review. 
 
 There remains yet the medical question. Were it not the ul- 
 timate and essential one, I would gladly have avoided it, because 
 it is no longer a question of reasoning and facts, but of medical 
 opinions and fashions. I must be brief in proportion ; and shall 
 be safe in saying, first, with physic, that fevers are proved to 
 arise from two great causes at least ; Malaria and human conta- 
 gion : the latter, whencever arising, enabling the sufferer to re- 
 produce a substance productive of similar effects. And whatever 
 other fevers there may be, from other causes, these two great 
 classes, are, in numbers, as a hundred, or ten hundred thousand, 
 to one, compared to the rest ; while also the fevers from Malaria 
 exceed those from contagion ten thousand fold, or far more. 
 
 The question remains. Is there any other simple fever, which 
 is not produced by one or other of these causes ? It is believed 
 that there are many ; to a certain extent, it is proved : but it is 
 also notorious, that such third class fevers bear a very minute pro- 
 portion to the rest, and what is of infinite importance, that they 
 are of little moment as diseases, from their little injurious proper- 
 ties. The error has been to consider the slighter fevers from 
 Malaria as belonging to these. 
 
 The final conclusion is therefore the following: that when I 
 have in the preceding investigation of causes, used the term fever 
 as a substitute for the more definite one remittent or marsh fever, 
 1 have in reality included the great majority of cases which oc- 
 cur in the world ; the very high majority, I should say : and that, 
 excluding of course the contagious fevers, or the second great 
 class, as being well understood, the conclusion which has been 
 drawn as to The Cause, Malaria, in as far as it is a conclusion of 
 utility and not of philosophy, (being all to which it pretends,) re- 
 mains valid for these purposes of utility. 
 
 Can it possibly be necessary, once more, to say to what all this 
 reasoning tends, as to practice or use ? If the great proportion 
 of the fevers which occur among mankind, in our own country as 
 in others, are fevers from Malaria, if this is especially true of 
 those which are serious or severe, omitting always the fevers from 
 contagion, then are we in possession of the cause ; and to possess 
 that is the first step towards prevention. If further, there have 
 been here truly pointed out the places and circumstances which 
 produce Malaria, or the causes of that cause, and if all these could 
 
MALARIA. 219 
 
 be avoided or destroyed, then fevers would occur no more. And 
 as far as they have been pointed out, and can be avoided or de- 
 stroyed, fevers must diminish : since, of other diseases, the conse- 
 quences of Malaria, I need not now speak. And lastly, if among 
 the fevers now supposed to be contagious, many, the much larger 
 portion, are not of this character, but are truly also the fevers of 
 Malaria, then have we made a most important step as to the pre- 
 vention of fevers in general, as far as we can diminish or control 
 the action of that poison. And all this depends, primarily, on 
 our proving the real cause of such fevers, and secondarily, on 
 our proving the causes of that cafuse ; this last knowledge prin- 
 cipally, being that which the present researches have attempted to 
 investigate. 
 
 I may thus terminate this essay ; or, as it will prove to those 
 who desire to seek further, this branch of one subject ; which I 
 have unwillingly thus separated from the consideration of the dis- 
 eases which are its effects. If it is not now as apparent as I hope 
 it is, to what useful ends the facts which it contains may be di- 
 rected, these will be rendered fully sensible hereafter : while I 
 cannot help believing that even what is here done, will, in the 
 end, prevent a great mass of evil, or of suffering and death ; and 
 that the views which are to follow, will also put it into the pow- 
 er, not merely of physicians, but even of the people, to lighten or 
 to avoid numerous disorders much misunderstood ; and, essential- 
 ly, as I trust, to diminish the total sum of human misery. 
 
 THE END, 
 
3kn-z 
 
LIBRARY OF CONGRESS 
 
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