TO THE DIRECTOR-GENERAL,

ARMY MEDICAL DEPARTMENT.

SIR,

I HAVE the honour to submit the Reports, &c., connected with the Medical Branch of the Army Medical Department, for the year ending 31st December, 1861.

Officers of the Department.

On the 1st of January, 1861, there were 1,033 Medical Officers on full-pay. During the year 22 Assistant Surgeons entered the Service; 15 Medical Officers died; 9 resigned; 8 retired upon permanent half-pay (7 from ill health, 1 from other causes); and 27 were placed upon temporary half-pay, on account of illness.

Medical and Surgical Transactions.

1. Observations on the Influence of Pandemic Causes in the production of Fevers, by Robert Lawson, Esq., Deputy InspectorGeneral of Hospitals.

2. Observations on Pulmonary Diseases, and their relation to Syphilis, by Dr. David Milroy, 30th Regiment. Also Notice of Pulmonary Lesions associated with Syphilis, contributed by Professor Aitken, Army Medical School, Netley, in further elucidation of the subject of Dr. Milroy's paper.

3. Reports on the Cases of Gunshot and Sabre Wounds of Invalids sent to Fort Pitt, during the year 1860-1 (extracted from the Annual Reports of the Surgical Division), by Thomas Longmore, Esq., Deputy Inspector-General, Professor of Military Surgery.

4. Extracts from the Annual Report and Return of Sick treated in the Lunatic Hospital, Fort Pitt, from the 1st January to the 31st December, 1861, by Dr. Barron, Staff Surgeon. 5. Case of extensive Abscess in both Kidneys, compiled from Official Records, by Dr. Rutherford, Deputy InspectorGeneral of Hospitals.

6. Case of complete Transfixion of the Abdomen by a Bayonet, by Dr. Todd, Staff Surgeon.

7. Excision of the Knee Joint for Scrofulous Disease of the Bones,

and recovery, by Dr. Fox, Staff Surgeon.

8. Abstract of a case of Ununited Fracture, by J. M. S. Fogo, Esq., Surgeon, R.H.A.

9. Report on Fever, by Dr. J. A. Marston, Assistant Surgeon, R.A.

Army Medical School.

The Report of the Fourth Session, which terminated on the 1st April, 1862, will be found at page 525.

Circulars, Memoranda, and General Orders, affecting the administration of the Medical Department of the Army and its Officers, issued during the year, will be found at page 527.

A List of the Officers of the Medical Department will be found at page 535.

I have the honour to be,

Sir,

Your most obedient humble servant,

HENRY MAPLETON, M.D.,

Deputy Inspector-General.

6, Whitehall Yard,

31st March, 1863.

MEDICAL REPORTS FOR 1861.

OBSERVATIONS

ON THE INFLUENCE OF PANDEMIC CAUSES IN THE PRODUCTION OF FEVERS.

By ROBERT LAWSON, Esq., Deputy Inspector-General of Hospitals.

THE expressions Epidemic, Epidemic Cause, Epidemic Influence, Epidemic Constitution, Pandemic Cause, or Pandemic Influence, occur so frequently in medical writings and discussions, as to show the general belief in the profession that the ordinary climatorial, endemic, and personal causes, are insufficient to account for the variations in the prevalence and fatality of disease; yet, wonderfully little is known as to the nature of the cause in question, its mode of operation, the complaints it induces, or the extent to which its influence is experienced; all of them points on which more extended information is required before the present ideas on the ordinary causes can be rendered more precise.

The advance of knowledge on this subject has been much impeded by the disposition, so strong among medical writers and observers, to regard disease as they individually see it, and to refer its prevalence and character to circumstances affecting, obviously, the population within their immediate sphere; while, had their investigations been extended to other countries a similar prevalence of disease might have been found, under local circumstances, very different from those thought so essential to its occurrence among themselves; thereby indicating the operation of some cause more extensively than they had reckoned.

It is proposed to elucidate this important subject, in connection with Fever, mainly with the assistance of the Statistical Returns of the Sickness and Mortality in the Army, from 1817 to 1836. These afford a continuous record of the progress of disease in bodies of men, small it is true, but pretty constant in number, and under nearly similar circumstances at each place. The stations extend from Ceylon to Jamaica in longitude, and from Great Britain to the Cape of Good Hope in latitude; they present a great variety of climate, and the greatest difference as to the ordinary endemic sources of disease, yet fevers prevail amongst them, presenting periods of increase and decline with much regularity, and which can often be distinguished at them all.

Disease being merely the reaction of the system under the influence of causes subversive of its normal and healthy functions, it is clear that whenever it arises such antecedents must have been in operation, and the previous action of the antecedents may be concluded from the results with as much certainty as in ordinary physical investigations. In etiology, it is true, the supposed causes are often numerous and complicated, and it may not be easy to say which one, or what combination of them, has been efficient in bringing about the result; but the only method of attaining this end is that pursued in physics, viz., eliminating one or more that are essential to a particular conclusion, and observing whether the result continues unchanged, or how far it becomes modified under the altered circumstances. In practice it is seldom allowable, or possible, to carry out this as if it were merely an experiment in physics or chemistry; but, nevertheless, a careful observer will often discover

in the position of those around him such a variety of circumstances as will enable him to make a sound induction. Often, however, after the closest examination, the evidence remains defective in some particular necessary to a satisfactory conclusion, in which case observers cannot be too careful to avoid substituting mere opinion, a practice which has existed, and still exists, far too generally among medical men, and which has checked the progress of medical science enormously.

Individuals, or bodies of men, differ greatly in sensitiveness to the causes of disease, according as they are acclimated or not. Change of station, and, much more, change of climate, subjects them to a modification of the external influences acting on the system; and some time elapses before the resulting modification of its functions is fairly established. While this transition is in progress, should the individuals be subjected to other causes of disease, such as malaria, exposure, fatigue, indifferent food, &c., especially if, during an epidemic period, it is found they are affected in higher proportion, and the mortality among them is much greater than among others who have become acclimated by a longer residence. Our military annals present many illustrations of the danger of sending troops abroad, especially to the tropics, during epidemic seasons; the history of the West Indies teems with them; and, even in temperate climates, military expeditions during such seasons have always been disastrous, such as that to Walcheren in 1809, and that to the East in 1854-5, while others, which have fallen on happier times, have been much less fatal.

It is frequently stated by those who hesitate to admit the operation of an epidemic or pandemic cause, that, were it existing, every locality within its influence should manifest the disease or diseases it is supposed to induce to nearly an equal extent. The answer to this is, that it is not found to be so. On the contrary, in a group of stations under the same general influence, the disease may prevail to a very different extent in each, and attain its maximum in one year at one, and in another at the next station to it, and so on; the persistence of the disease showing the continuance of the general cause, though its local manifestations vary from time to time, owing to peculiarities in the meteorological or local circumstances. As it is important to place this point in the clearest light, the mortality from fevers, mostly remittent or yellow, is given below for three groups of stations, from 1829 to 1831 inclusive, during which fever was very prevalent both in the Mediterranean and West Indies. TABLE I-Annual Mortality per 1,000 mean strength, from Fevers, at under mentioned Stations.

The places in the first group in the above Table lie on the west coast of Albania and the Morea. Corfu is about 60 miles north from Santa Maua; Cephalonia and Zante lie to the south of the latter, in the order named, and the three from north to south do not cover more than 70 miles.

The West India group extends from lat. 7° to 17° N., and from long. 57° to 62° W., in the order named. The stations in Jamaica are all on the south of the island; and, from Fort Augusta, the most central, Port Royal is distant 2 miles to the southward, Up Park Camp, 5 miles to the eastward, Stoney Hill, 8 miles to the northward, and Spanish Town, 8 miles to the westward.

On examining the Table, the mortality from fever at Santa Maura is found to have attained its maximum in 1828, and to have remained high for the next two years. Corfu attained its maximum in 1827, and subsequently declined. Cephalonia had its maximum in 1828, with an abatement in 1829, and a second maximum in 1830; while Zante had maxima in 1827 and 1830, with very little mortality between.

Taking the West Indian group, it shows, as in the Ionian, a high rate of mortality from fever from 1827 to 1830, but differing in each year, and the maxima occur in different years in contiguous islands, without regularity as to geographical position. Thus, at Demerara the mortality was highest in 1827, with but little abatement in 1828. The maximum at Trinidad was in the latter year; at Tobago it went on increasing till 1830; at Grenada the maximum was in 1828; at St. Vincent in 1829; and at Barbadoes and St. Lucia in 1827; at Dominica the mortality was highest in 1826, while at Antigua the maximum was in 1827, and in 1828 the mortality was almost as large.

The stations in the Jamaica group all attained their maximum in 1827, save Spanish Town, in which the mortality in 1826 exceeded that of 1827. The subsequent course, however, was very different; Port Royal had a very low minimum in 1828, from which it increased to a high maximum in 1830, and in 1831 had not a death from fever. Fort Augusta, within two miles of it, retained a high mortality from fever in 1828, had its minimum in 1830, and more than doubled that again in 1831. Up Park Camp had its minimum in 1829, had a second maximum in 1830, and declined somewhat in 1831. Stoney Hill was low in 1829 and 1830, but the mortality there increased very greatly in 1831. Spanish Town had its minimum in 1829 also; there was a great increase in 1830, and in 1831 the deaths were more numerous than in any year in the Table.

Though these facts be conclusive as to all places within the operation of an epidemic constitution not being similarly affected as to time and degree, more striking illustrations still can sometimes be obtained from the course of disease at a single station. Thus, at Newcastle in Jamaica, where the cantonment consists of a series of wooden houses accommodating about 34 men each, and which are erected on the crest of a narrow mountain ridge, from 3,500 to 4,100 feet above the sea, fever prevailed in 1856 from September till December, causing considerable mortality. The cantonment is only about 800 yards in length, and within this space there were four zones, embracing all the huts or tents right across the ridge, in which fever scarcely showed itself, while there are three intermediate zones in which it was both frequent and fatal.* All were exposed to the same epidemic influence; but within half a mile there were no less than four positions of immunity from disease, alternating with three others in which it was both frequent and fatal. Marked limitation of the disease to certain buildings, while those in the vicinity continue exempt, is not unusual in the history of yellow fever.

Facts of this description show that little weight can be attached to the evidence sometimes adduced from epidemic disease not having invaded localities under quarantine. There was no attempt to limit communication at Newcastle in 1856, and yet the prevailing fever confined itself within certain limits. Had the healthy zones alternating with these been placed in rigid quarantine from the commencement, many would have concluded that that had preserved them from attack, whereas the result showed that, with the freest personal communication, fever did not develope itself in them.

*"Observations on Yellow Fever among the Troops at Newcastle, in Jamaica.” Brit. and For. Med. Chir. Rev. October, 1849. p. 445, et seq.