From the foregoing tables it will be seen that our late epidemic, in its prevalence and virulence, had two maxima, which were divided by the year 1840. In fact, from the gradual diminution of virulence in the intervening period between the maxima points, it would seem as if our last had been a double epidemic. In the last six months of 1840 there were but 14 deaths out of 613 total admissions into the Seaman's Hospital; or 9 deaths out of 225 yellow fever cases. This interval contrasts strongly with the more abrupt lull which occurred in December, 1837, and beginning of 1838.

It is also seen that the epidemic has been subject to the general laws which influence the prevalence and virulence of febrile and other colonial disorders generally, as respects months, and that the vernal equinox through all conditions persists in being the healthiest period of the year."

*

The termination of the epidemic was preceded by the prevalence of the "simplex" form, denoting that the virus had become gradually weaker; till, at last, in the great rainy season of 1845, it entirely ceased, superseded by a slight, but a very general influenza.†

* [The following Return of Deaths from Fever, in Barbados, is given for the purpose of comparison; the accordances do not require to be pointed out, whether as to duration, fluctuation, or apparent influence of season. RETURN OF THE DEATHS From Fever, monthly, amongst THE TROOPS IN THE GARRISON OF ST. ANN, BARBADOS, EXCLUSIVE OF OFFICERS, FOR A PERIOD OF ELEVEN YEARS, IN THE FIRST SIX OF WHICH, AND THE TWO LAST, YELLOW FEVER WAS THE PREVAILING FORM OF THE DISEASE.

1838. 1839. 1840. 1841. 1842. 1843. 1844. 1845. 1846. 1847. 1848. Totals.

In 1844 the first cases of scarlatina known to have occurred in the colony were seen. The subjects of it, however, were chiefly children of the colonists, and those of the mixed races.

Occasionally since then the suffused face and eye, frontal headache, and crimson-edged tongue, have been seen engrafted on the intermittents of the seamen of the shipping, showing that

* The following return may be useful, as bearing upon some of the points RETURN SHOWING WHEN REMITTENT OR YELLOW FEVER

1842 From Nov. till Jan. 1843. 46th Regt. 552

NOTE.-4 Seamen of the Royal

Navy died of Yellow Fever.

81st Regt.

294

1843

to 1846

22223

31

5

112

1 22

a taint still exists; but, since the period named, the yellow fever has ceased to have a separate existence among the diseases of the colony.*

discussed in this chapter; it was drawn up carefully from documents in the Inspector's Office, Barbados. [See pp. 46. and 47.]

WAS PREVALENT IN BARBADOS FROM 1815 TO 1846.

No prevalence.

Remarks.

Prevailed in the Brick Barracks, and Brick Barracks
Officers' Quarters. It had been prevalent in
Bridgetown for nearly seven months previously.

No prevalence.

Prevailed generally in the Garrison and its vicinity, in the Dockyard, and in Collymore Rock.

Prevailed in the Garrison; but the Barracks not mentioned.

No prevalence.

Prevailed in the Stone Barracks.

No prevalence.

Prevailed in the Brick Barracks-Officers' Quarters.

2 16 Prevailed in Brick Barracks- Soldiers' Quarters.

8

16 Prevailed in Stone Barracks, and on board of her Majesty's ship" Crocodile ;" and amongst the Detachment of the 81st Regiment arrived in the "Crocodile" from St. Kitts. Some cases occurred in Hospital amongst the Patients and Orderlies.

No prevalence.

CHAP. V.

MORTALITY OF THE EPIDEMIC YELLOW FEVER.

It is difficult to discover what per centage of mortality occurred in purely untreated cases. From the first, however, it did not require much nicety of observation to find out that the number of deaths among a given number of cases, as well as a given number of cases among a certain number of susceptible persons subjected to similar exposure, had determinate laws. The early appreciation of this fact was of great service to the reputation of the medical practitioner at a time when the treatment was nearly totally inefficient. I find among my earliest notes of the epidemic a remark on what I call the complement of mortality, and one or two instances of an application of the knowledge of it. The barque "Glasgow" (Milrae, Master,) was attended by Dr. F., who was exceedingly unfortunate with the cases on board of this Clyde vessel. Seven or eight of the crew had died, and the rest, including the Master, were so disheartened, that it was determined to change the practitioner, and I was requested to take charge. Having no desire thus to supersede Dr. F., I declined, and explained to the shipmaster that it was highly probable that, henceforth, there would be no more deaths on board, as the complement of mortality was already full. The result was as predicted. In the same note I find it stated, of course on mere general observation, "The mortality generally ceased below 8 in the Bristol, Liverpool, London, and Clyde vessels, and below 4 in the Belfast vessels." This was during the first half of the epidemic. Perhaps the mortality of the Babel temporary Seaman's Hospital might be taken as the mortality of untreated cases; for from the total disorder and want of supervision in that establishment, and the inadequacy of the sick-nurse attendants, it is likely the disease was in no way beneficially affected by the treatment prescribed.

Many trivial cases were no doubt admitted in the general alarm; so that this dilution would compensate in the deduction of an average made from observations at the beginning of an

epidemic. Several ships which sailed from this port in the early period of the epidemic had cases occurring at sea, in which all attacked died. But it is probable there was compensation by previous cases of recovery. If the mortality of the temporary hospital be taken to represent the proportional deaths from the untreated disease, we must assume it at 29 per cent. The mortality of treated cases as educed from records of the present Seaman's Hospital, will give a full, or even an excessive, rate; for many cases were admitted in a hopeless condition, the medical practitioners in many instances making the hospital a receptacle for such cases as they feared would terminate fatally.

Our epidemic, as has been stated of scarlatina, varied in intensity from a "flea bite to the plague." The simplex cases represent the former lesion named in the quotation.* It will be well, therefore, to give the centesimal mortality of the epidemic as shown in the Seaman's Hospital from 1839 till its termination for each form or variety, as in the annexed table.

* [The mortality, probably, in no two invasions of yellow fever will be similar. The following table shows the proportion per cent. of deaths, to the number of fever cases admitted in the military hospitals in Barbados, from 1816 to 1842. It may be proper to premise, that the terms remittent, communis continens, and icterodes, as commonly used, are hardly distinctive; sometimes, according to certain preconceived ideas, one name being used, sometimes the other.

PROPORTION PER CENT. OF DEATHS TO THE NUMBER Admitted.

† This form, as before stated, was noticed and recorded first in 1841.

E