wave," the term epidemic referring rather to a single form of disease affecting a limited space.

What the nature of this pandemic wave and its mode of action may be, it is difficult to say; but certain deductions may be made with advantage from the facts concerning it set forth above. Of these the most striking is the constant course in the Atlantic and western part of the Indian Ocean, from south or south-east to north or north-west. This can take place in virtue of some law of nature only, and the situation of the magnetic poles immediately suggests itself as being in some way connected with it; but of this there is not at present any proof so far as I am aware.

Another point of more immediate importance, as bearing on some of the medical opinions of the day, has been alluded to several times in the course of this paper, viz., the occurrence of every form of fever under the operation of the same pandemic wave, yellow fever, remittent, intermittent, and continued fever, and plague, having prevailed in the localities in which they were endemic, as the wave passed over them. Sometimes, it is true, one of these forms invaded the territory of another for a while, and such intrusions have given rise to some of the most embittered controversies in the history of medicine. The principles here developed will place the evidence in connection with these unusual irruptions of disease in a new light, and contribute to reconcile the opposite opinions regarding them, giving us a basis to reason on epidemics better suited to the time, and the advance of our knowledge of the causes of disease, than that on which the subject was contested by Pym and Pancroft fifty years ago.

Though, as a general rule, the peculiar form of fever developed is that usual to the locality, still there are exceptions, and of sufficient importance to require more particular notice. Thus, yellow fever is only an occasional visitant at Sierra Leone, and on the Coast of Africa, Gibraltar, Bermuda, New Orleans, &c. Plague, though commonly confined to Barbary, Egypt, Syria, and Turkey in Europe, has shown itself elsewhere, as at Malta in 1813, in the Ionian Islands in 1815-16, at Noja, in Naples, in 1817. A type of fever, which first attracted attention at Rangoon and Calcutta in 1824, was seen in the West Indies and America in 1827-28. These casual irruptions of the new form of the disease have always taken place during the passage of a pandemic wave, and other places under the influence of the same wave manifested other forms of febrile affections. There are many instances of this; for example, in 1828, fever, chiefly yellow, produced a mortality at Gibraltar of 121.1 per 1000 of strength; at Santa Maura, the same year, the mortality from fever, chiefly remittent, was 1497 per 1000; petechial typhus prevailed at Naples, and plague in Albania and the Morea, and over Turkey, Syria, and Egypt. If particular instances be taken, two fevers may be found in close contiguity: thus, plague appeared in Corfu at the end of 1815, in a marshy district, in which remittent had prevailed just before, and was thought to have been limited by quarantine, until it ceased in May 1816; that year it broke out in the village of Comitato, in a mountainous situation in Cephalonia, in the beginning of June; no means were taken to limit it before the end of the month, but nevertheless it did not attack any one out of the village, where it ultimately disappeared in the middle of July.* The garrison of Cephalonia in 1816, according to Hennen, consisted of 396+ men, and the deaths from fever were 78, or 197 per 1000 of strength; the inhabitants also suffered more from fever that year than usual. Such facts lead to the conclusion that the pandemic cause can determine, to a certain extent, the resulting form of fever, though local and temporary circumstances may often be more powerful in this respect, and may even determine a different form, or suspend its operation altogether for the time, instances of which may now be given.

At Sierra Leone the prevalent fever was remittent, unless in 1823, 1829-30, 1837-38, and 1847. In these years yellow fever prevailed, but not exclusively. In the first three it broke out after some showers had fallen, but before the

* (C Statistical Report on the Mediterranean," p. 39.

"Topography of the Mediterranean," pp. 298 and 302. At page 283 the strength is stated in the text to have been "three hundred and seven," which would have made the mortality 254 per 1,000.

periodical rains fairly commenced; and on these setting in heavily, the form changed to remittent. In 1823 there was a break in the rains, in the middle July, when cases of yellow fever appeared again, but on their recurrence, remittents only showed themselves. In 1837, on the decline of the rains, cases of the yellow fever again appeared. In 1847 the disease was later in showing itself; the rains had commenced as usual, and 12:44 inches fell between the 4th and 21th June, and the early cases of fever were common remittents. From the 25th June to the 4th August, there were only 9 58 inches of rain, as against 31-33, the corresponding period in 1848. The first case of the yellow form occurred an the 29th June, and the disease prevailed during this period. The wet season was rather i regular in 1847, and dropping cases occurred at intervals afterwards, but chiefly during the periods of comparative absence of rain; the majority of the attacks, however, were those from remittent. On the cessation of the rains, some other cases of yellow fever presented themselves*. These alternations of remittent and yellow fever, as the rain was more copious or scanty, show a connection between the meteorological conditions and the form of the disease too obvious to be overlooked. In fact, in Sierra Leone, as elsewhere, yellow fever is a disease of fine weather. A certain amount of rain, or moisture under the surface, must have preceded its outbreak ; but much of either checks it, until the return of more settled weather, with a brighter sky and stiller atmosphere. A striking instance of the power of heavy rain to suspend yellow fever was afforded at Newcastle, in Jamaica, in 1856, when the disease nearly disappeared for three weeks in November, during wet weather, but commenced again as it became settled and fine. The effect of rain, followed by a warm, still state of the atmosphere, in inducing fever, is described in a very interesting and circumstantial manner in Mr. Ralph's Memoranda on the Yellow Fever in the 2nd Regiment at Barbadoes, in 1816, and is well worthy of perusal. †

It is an interesting subject of inquiry whether the pandemic cause acts on the system, rendering that more susceptible of the influence of the ordinary causes of disease, or on these themselves, giving origin to a more concentrated, or a different kind of poison, which generates a more virulent, or a new form of disease; or whether it affect both, increasing the activity, or altering the kind of the causes, and enhancing the liability of the body to be affected by them. Our information on these points is still very limited and unsatisfactory. I have observed that prior to, and during the prevalence of, an epidemic of yellow fever, the urine contained an unusual quantity of urrhodine, giving a deep reddish brown when treated with nitric acid and set aside for some hours. Something similar has been observed with regard to cholera. These tend to show that the body itself is affected by the pandemic cause; but the observations require to be repeated, before much weight can be attached to them.

The outbreaks of epidemic disease have been referred immediately by some to the rapid generation and diffusion of myriads of microscopic animals, and by others to a similar production of vegetable organisms. The evidence in support of either is very defective. It may be well to keep the possibility of such things occurring in view, while we cannot be too cautious in admitting their efficiency, without adequate and irrefragable proof.

In the above remarks, the influence of the pandemic wave in producing fever only has been examined, but it is obvious in many other affections, of which cholera, diarrhoea, dysentery, and scurvy, are perhaps the most important. Even consumption and ulcers vary so much from time to time in frequency, as to suggest that they are similarly affected.

These facts are mostly from the official reports of Barry, Schetlz, and Fergusson, to which I had access at Sierra Leone. The information for 18 17 was the result of my own observation on the spot.

In Bancroft's "Sequel to an Essay on Yellow Fever," p. 443. This work cannot be too strongly recommended to the attention of the junior medical officers in the army, as containing much interesting and useful information.

Brit. and For. Med. Chir. Rev., p. 475.

OBSERVATIONS

ON PULMONARY DISEASES, AND THEIR RELATION TO SYPHILIS.

BY DAVID MILROY, M.D., Assistant-Surgeon, 30th Regiment.

Sometime has elapsed since the attention of the medical profession and the public was called to the alarming loss for many years sustained by the Army from the ravages of Pulmonary Consumption. Various causes were then assigned to account for the prevalence of this malady, of which over-crowding in barrackrooms, night-duty, and want of variety in diet, appear to have been the most favoured. But although it was known, that, while phthisis thinned the ranks by death and invaliding, a most important deduction from the available strength of the Army was occasioned by the number of men constantly under treatment for venereal complaints, little importance was attached to what was regarded as a mere coincidence. In the minutes of the evidence taken by the Commission appointed to inquire into the Sanitary Condition of the Army, there is, however, a statement by Dr. Balfour, Deputy Inspector General of Hospitals, which shows that this officer's attention had been directed to the subject, "I think" he says, "that another great cause of pulmonary disease among the Guards is the amount of syphilis, which I have not the least doubt, in men who have any predisposition to tubercular disease, is a very fertile cause of its being called into active operat on."

About three years ago a very able paper by a member of the Army Medical Department, appeared in the Edinburgh Monthly Medical Journal, in which the author shows cause for believing, that, in the army at least, phthisis may in many cases be regarded as the product of syphilis; but he does not adduce instances in favour of this opinion. While admitting that statistics may mislead, I cannot but regard them as the most certain means at our command for eliminating truth, and I believe that to them we must look for an answer to the question,does a large proportion of cases of pulmonary diseases, more especially phthisis, stand to syphilis in the relation of effect to cause?

I propose to take the cases of pulmonary phthisis which occurred in the 30th Regiment from its arrival from foreign service in September 1857, to its leaving the United Kingdom in June 1861, and to ascertain in what proportion of them the diseases in question could be satisfactorily regarded as produced by the action of syphilis on the system. In the following Table I have confined myself to such cases as died or were invalided; as these events form a very fair test of the actual presence of the disease. During this period, and long antecedent to it, I was attached to this corps, and possessed an acquaintance with the medical history of the individuals composing it. A very short time after the commencement of the period under review, my attention was directed to this subject, and I have been in the habit of making an examination of the lungs of patients discharged from hospital after treatment for primary syphilis, especially when their health appeared to be impaired, although secondary symptoms had not shown themselves; and of recording any facts of importance in my note-book. I have thus been able to trace the history of the disease at subsequent examinations of cases in which it occurred.

It appears from this Table that out of 50 men who died or were invalided for phthisis, or for affections with which it co-existed, evidence of deterioration by syphilis existed in no less than 43. In 4, the proof was insufficient, while in 3 others, (although in 2 at least there was reason to suspect that that disease might have played a part in inducing debility), no evidence could be produced to satisfy me that it had done so. The cases I shall relate will sufficiently convey what I mean by the term deterioration of system.

Since the departure of the regiment from the United Kingdom, three cases of pulmonary phthisis have presented themselves in patients of whom two,Wal-h and Eyers (see cases)-were manifestly broken down by syphilis, in the remaining one, no such evidence was forthcoming.

The number of cases given, may perhaps appear to be small, but I think it advisable to take such only as came under my own particular notice. I may, however, mention that I have seen many men in other corps, in whom the history of the disease pointed to an attack of syphilis as its starting point. Although I believe that the connexion between the one disease and the other, is not so frequently met with among the civil population as in the army, vet that it does frequently exist, I feel perfectly satisfied from such observations as I have been able to make in the hospitals of large cities, and from cases which have been casually brought to my notice.

Happily all cases of secondary syphilitic disease do not terminate in phthisis. What then are the causes which superinduce the one cachexy on the other? A very plausible theory is that syphilis is most severe in subjects predisposed to phthisis, or, in other words, that the scrofulous individual is most liable to severe attacks of syphilis.* On the other hand, we may throw the onus on the shoulders of mercury; or, with still more appearance of probability, it may be said that as the use of this mineral is known to be ill borne by scrofulous individuals, its administration in such cases may lead to tubercular deposition in the lungs.

With regard to the first proposition, Mr. Holmes Coote, says, "I have never noticed any connexion between that state of constitution commonly called scrofulous, and a predisposition to secondary syphilis. As has been remarked, constitutional syphilis attacks, without much distinction, old and young, strong and weak, rich and poor, male and female." Others again have endeavoured to trace a connexion between the hard sore and a scrofulous state of system. I cannot say that I have observed this sore to be so peculiarly apt to entail secondary affections more frequently in this habit of body than in others, but

*Mr Acton says, "It might be said with more truth, that the consumptive individual presents the most severe case of syphilis; still I am ready to admit, that when syphilis occurs in delicate persons, it may develop the seeds of scrofula, and in this it will be aided by the injudicious use of mercury."

Total.

when such sequelae do occur, they are distinguished by unusual severity. It certainly appears of little moment by what agency the constitution is depressed; if it be so, secondary disease is liable to follow the primary ailment. Still scrofula cannot be said to prevail to a great extent in the army, as marks of its presence in a recruit forms an unqualified ground for rejection. Soldiers may be considered as "picked lives," and although during the Crimean War and Indian Mutiny, a class physically less eligible than formerly was admitted, the 30th Regiment, at least, has always contained a considerable proportion of old soldiers. I am unable to give the ages and services of the men invalided, but I insert these particulars in the case of those who died of phthisis.

The average age was 25, the average period of service 5 years and a fraction. Most of the cases died shortly after 1857, and consequently must have enlisted prior to the Crimean War, when a good selection could be made. On looking over the names of the invalided men, I find that the same observation holds good with regard to them also.

"Syphilis," says M. Ricord, "is the spur, and mercury is the whip, which hurries along the phthisical to their graves." Without entering into any controversy on so vexed question as the use of this mineral in the treatment of syphilis, I may say, that in scarcely one of the cases referred to were mercurial preparations given for the primary affection; and, as a rule in the earlier cases, they were withheld even in the secondary forms of the disease, except in cases of iritis.

The comparative youth of the soldiers of the present day might be sufficient to explain the frequent occurrence of phthisis among them; whether syphilis did or did not play as important a part a few years ago in inducing consumption as it appears to do at present, the last table, as well as the general statistics of the whole army at home, incline me to consider such an explanation unsatisfactory. In former times overcrowding in barrack-rooms no doubt exercised an injurious influence on health, and the same may still be said with regard to the less easily avoidable night-duties and severe drills. The first case I shall mention, and I could supplement it with many others, shows, that when a man is for a time relieved from duties necessitating much exposure, particularly at night, the deposition of tubercular matter in the lungs may remain stationary, or the deposit may become re-absorbed, if not prevented by a return to them; and it may be surmised that any duty involving constriction of the chest, or impediment to the free action of the lungs, may even induce such deposition. Night-duty will chiefly act by inducing bronchitis, which, although frequently said not to cause phthisis, has, in the cases of which I speak, as I shall afterwards show, no unimportant influence. The predisposing circumstance to which I shall allude lastly, though by no means entitled to this place in point of importance, is habits of dissipation. A large proportion of my cases occurred among hard drinkers, who as such were exposed not only to the direct effects of intemperance, but also to exposure to vicissitudes of weather when intoxicated, and to punishment, by severe drill or incarceration.

Having alluded thus briefly to the etiology of this disease, I proceed to notice its history and diagnosis, as illustrated by the cases which have come under my notice. The relation of the leading features of a few instances, out of many of which I have preserved notes, will be appropriate here. I have