occurred. In July there were 813 cases in 25 villages. The Naldurg district with 362 cases in 10 villages, and the Gulburga district with 308 cases in 6 villages, were worst infected, 123 cases being reported in the Lingsagur district and 19 cases in Bidar.

In August plague was reported from 38 villages in the State, and the number of cases rose to 985. 247 cases occurred in Gangawathi, a village in the Kushtagi sub-division of Lingsagur, and eight other villages in that district had 82 cases. 482 cases occurred in the Naldurg district, in which the worst affected tract was that of Ganjoti, containing, among other infected places, the town of Umerga, which reported 79 cases in August, and 86 in the previous month,

In September the total number of infected villages rose to 48, and the number of plague cases to 1,334. The Naldurg district continued to be the worst infected. In it 844 cases were reported from 24 villages; the number of cases in Umerga fell to 13, but Muram had 249 cases, and Alur 119. The Lingsagur and Gulburga districts had 8 and 11 infected places with 273 and 180 cases respectively, the places with most plague being Gangawathi (139 cases) and Lingsagur (63 cases) in the Lingsagur district, and Jawargi (110 cases) in Gulburga.

IV.-(5.) Course of the Plague in the Madras Presidency in July, August, and

September, 1899.

121. In the Madras Presidency, outside the Salem district where the outbreak Madras was not severe, there was practically no plague during July, August, and September Presidency. July, August, and 1899. Anantapur had four cases in two places in July and August; North Arcot September 1899. reported one case in July and another in the fortnight covering the end of September and the beginning of October, and Bellary also had one case in the period last mentioned. In Salem, from the 1st to the 29th July, six places reported 34 cases; in the next four weeks 11 places reported 22 cases; and in the six weeks ending on the 8th October there were 13 places infected, in which 88 cases were reported.

IV.—(6.) Course of the Plague in the Central Provinces in July, August, and September,

1899.

122. In August 1899 plague re-appeared in the town of Nagpur, in the Central Central Provinces. Provinces. Up to the 30th August 22 cases occurred, while between the 30th August August and and the 1st October the number of cases in the town rose to 154. The outbreak September 1899. continued after the end of September. A village near the town was infected in the beginning of September by a contact who had got out of Nagpur, but prompt measures suppressed the outbreak in the village, after two fatal cases had occurred. At the end of September two other villages became infected.

IV.-(7.) Course of the Plague in Bengal in July, August, and September, 1899.

123. In Bengal plague occurred during July, August, and September, 1899, only Bengal. in Calcutta and Howrah. The number of cases and deaths reported in Calcutta gradu- July, August, and ally increased from 10 cases, all fatal, in the first fortnight of July to 113 cases, September, 1899. with 110 deaths, in the last fortnight of August. In the first and second fortnights of September respectively there were reported 103 cases, all fatal, and 100 cases, of which 99 were fatal. The total for the three months was 460 cases and 454 deaths. It is to be noticed that on the average of the mortality returns for past years, on the assumption that there was no exodus at this time, 2,406 deaths from all causes might have been expected to occur from the 16th August to the 30th September, and that in 1899 in this period the number of deaths that actually did occur was 2,684. In Howrah there were during July, August, and September 1899, 16 cases of plague with 15 deaths; uine of these cases with eight deaths occurred in the first fortnight of August, and there was only one case and death in September. In the last fortnight of September a few cases suspected to be plague occurred in the Saran district.

IV.--(8) Course of the Plague in the Punjab in July, August, and September, 1899.

124. In the Punjab there were five cases on the 16th July 1899, in a village Punjab. of the Murree revenue subdivision of the Rawalpindi district. These cases all July 1890. ended in recovery, and they were not followed by other cases. A few cases occurred

in a village which had been infected in June in the Hoshiarpur district, but the disease practically disappeared from the Province by the end of Ĵuly 1899.

General remarks

on the mortality from plague.

I. 306. 1601.

23,518. 2192.

Total recorded

plague mortality

in India from

September 1896 to

September 1899.

India not high in comparison with total mortality

V.-GENERAL REMARKS ON THE MORTALITY DUE TO PLAGUE IN INDIA.

125. It will be observed from the details given above regarding the outbreaks at the larger centres at which plague has occurred, that the differences in the proportion of the population which has been attacked and has died at different places have been very striking. In some places the percentage of attacks and deaths has been very high. Up to the 29th September 1899, counting indigenous cases only, and stating populations according to the returns of the Census of 1891, there had been in the different outbreaks which have attacked Poona City and Cantonments and Kirki 23,262 reported cases with 18,033 deaths out of a population of 172,341; in Karachi City, 10,498 cases with 8,156 deaths out of a population of 105,199; in the town of Bulsar, 1,625 cases with 1,191 deaths out of a population of 12,999; at Bhiwandi, 3,004 cases with 2,197 deaths out of a population of 14,387; at Karad, 2,171 cases with 1,714 deaths out of a population of 12,374; in Belgaum City and Cantonment, 6,826 cases with 5,298 deaths out of a population of 41,413; at Sangli in the Sangli State in Kolhapur, 3,010 cases with 2,682 deaths out of a population of 14,798; at Shahapur in the same State, 2,202 cases with 1,921 deaths out of a population of 12,046; at Cutch Mandvi, 6,999 cases with 5,832 deaths out of a population of 38,155; at Bantwa, 944 cases with 602 deaths out of a population of 8,200.

In some small places the mortality was still more appalling. It is estimated that in the Portuguese Settlement of Lower Daman 2,000 out of a population of 7,000 died between the end of February and the beginning of June 1897. In the Dharwar district some villages suffered fearfully during the autumn of 1898. At Ibrahimpur (population 1,716) the attacks came to 50, and the deaths to 35, per cent. of the population; at Ingalhalli (population 2,203) the corresponding figures were 48 and 37; at Datnal (population 1,280), 45 and 36; at Shelwadi (population 4,222), 32 and 28; at Lingdhal (population 1,459), 30 and 25; and at Bayahatti (population 3,589), 28 and 22. We have quoted these instances to show how severe an outbreak of plague may be. Although this enumeration does not exhaust the list of very severe outbreaks, cases in which the mortality has even approached these figures have been very rare. The number of outbreaks in which even 10 per cent. of the population. has been attacked is comparatively small.

126. The deaths reported up to the 29th September 1899 as due to plague in the Bombay Presidency, including the Native States connected with that Presidency, number 250,677. The plague deaths reported up to the end of September 1899 from other Provinces of British India and from Native States outside Bombay number about 36,300. There is, however, no doubt that the reported deaths do not represent the real mortality from plague, and in order to obtain an adequate estimate of the mortality due to the present epidemic of the disease in India, we may, without undue exaggeration, assume that even as many as 35 per cent. of deaths really due to plague have been wrongly assigned to other causes. On this assumption the mortality from plague in the 36 months from September 1896 to September 1899 amounts to over 376,000 in the Bombay Presidency, and to about 54,450 in the rest of India. This computation gives a total of about 430,500 deaths for the whole of India.

If we restrict ourselves to the figures for the Bombay Presidency and the connected Native States, within which plague has been principally confined up to the end of 1899, we find that, in a population which in 1891 amounted to about 19,400,000, the computed number of deaths from plague in three years represents 19 per cent. of the population, and, if the mortality were spread equally over the three years, this would give an annual death rate of 6 per cent. The effect of plague, however, on the mortality of the whole of India has been much less than this. The population of the whole of India may, without taking account of any increase that may have occurred since the census of 1891, be taken as being over 287 millions, and a calculation on this of the computed number of deaths up to September 1899 shows that only 15 per cent. of that population has during three years died of plague, giving a death rate that is equal to an average mortality of 05 per cent. per annum.

Total plague mor127. A comparison of the above figures with the vital statistics compiled for India tality recorded in during recent years shows that the mortality from plague has not as yet attained to any considerable proportion of the total mortality of the country, and that plague has not in three years been able to extend and take a hold of the country in such a way as seriously to affect the ordinary death rate. In British India the average annual number of deaths from all causes during the six years from 1893 to 1898 has been about 6 millions, in a population which may be reckoned at 221 millions on the

from "fevers" and

cholera in India.

census of 1891 and without making allowances for any increase that may have occurred since the census. The figure, 6 millions, may be taken as fairly representing the average mortality of an ordinary year. The diseases which contribute most to this total are "fevers" and cholera. The incidence of mortality from " fevers" and cholera varies considerabiy in different parts of India; the mortality from cholera varies considerably from year to year; the mortality from "fevers," which is very inaccurately classified but in the main represents deaths which are the direct or indirect results of malaria, is fairly constant from year to year over the whole of British India. Calculated on the returns for the years from 1893 to 1898, the average number of deaths from cholera in British India was about 370,000 per annum, or about 16 of the population, the cholera mortality in the Bombay Presidency, excluding the connected Native States, being about 14 per cent. of the population; while the deaths from "fevers" amounted annually in British India to more than 4 millions, or about 2 per cent. of the population. Taking with these figures the figures which we have given above for plague, we find that, in the three years following the appearance of the present epidemic of plague in Bombay, although the mortality from plague in the Bombay Presidency has been far larger than the average mortality from cholera in the same area, the plague mortality has not, over the whole of India, approached the average mortality from cholera, while over the whole of India the plague mortality of three years amounts to only a little more than 9.5 per cent. of the mortality attributed in British India to "fevers" in a single year, and has equalled about 6 6 only of the total mortality in British India in an ordinary year. Thus, although the figures of plague mortality when taken by themselves are high, it is evident that plague has not as yet been able to make itself felt as one of the most important factors that influence the total mortality of India.

CHAPTER III.

CHARACTER OF PLAGUE, AND THE MEANS BY WHICH THE DISEASE

IS COMMUNICATED AND SPREAD FROM PLACE TO PLACE.

I. SCOPE OF CHAPTER.

128. We have embodied in the historical survey which forms the subject-matter of Scope of the the last Chapter, the results of our special inquiries into the origin of plague epidemics Chapter. in some of the more important centres of population which have been visited by the disease in India. It will have been seen in the course of that survey that in none of the centres in question was definite information available as to the manner in which the plague was introduced. In this Chapter we proceed to describe the character of plague and to study in detail the means by which the disease is communicated and spread from place to place. With a view to throwing light upon these questions, we propose on the one hand to draw upon the clinical and bacteriological facts which have been obtained from a scientific study of the disease and its specific infective agent, the plague bacillus, and on the other hand to draw upon the epidemiological observations which have been furnished to us by Medical Officers and others engaged in plague operations in India.

129. It will be well to preface our consideration of the wide ranging subject-matter Order in which which will come under review by setting forth in brief synopsis the plan adopted the subject-matters are discussed in in this Chapter. this Chapter.

We commence by setting forth so much of the main features of the disease as is Main features of essential to the proper appreciation of the facts which come under consideration in plague. connexion with the spread of plague.

This done, we consider the plague bacillus, dealing first with its morphological and Bacteriology. cultural characteristics, the conditions which favour its growth, and its powers of resistance outside the organism. Following upon this, we discuss the means which are

Mode of infection.

Incubation period.
Clinical features.

Infectivity of persons, rats, houses, and other objects.

Manner in which

available for differentiating the specific infective agent of plague from other bacteria, by microscopical examination, cultivation on artificial media, and inoculation into animals.

We then pass to the discussion of the mode in which the infective agent may effect an entrance into the organism.

The duration of the incubation period is next discussed.

The detailed description of the clinical symptoms and pathological anatomy of plague and the consideration of the statistical data available with regard to case mortality and the relative frequency of various clinical forms of the disease, and also certain facts with regard to the recurrence of the disease in the same person, would, at this point, quite naturally have come up for discussion. But, inasmuch as these questions have only an indirect relation to the particular subject-matter in hand and lie somewhat outside the scope of our Reference, we have decided that they can best be dealt with in Appendices. In Appendix I., for which we are jointly responsible, will be found the purely statistical matter which we have collected, and in Appendix II. the clinical features of plague have been dealt with by the President.

We therefore pass on directly from the discussion of the incubation period to the discussion of the infectivity of plague. Beginning the consideration of this question by treating of the infectivity of plague patients generally, we then consider, under a series of separate headings, the infectivity of the various clinical forms of plague. After disposing of the question of the infectivity of the human patient, we consider the question of the infectivity of rats infected with, or dead of, the disease. The infectivity of dwelling-houses, of clothes and household effects, and of merchandise, which may have come in contact with plague patients or plague rats, next comes under consideration.

The discussion of the questions dealt with above will then naturally lead up to the the disease spreads. consideration of the manner in which plague spreads from infected to uninfected towns. and villages, and then from house to house within an infected town or village; incidentally, and with a view to making our discussion of the question of spread complete, we deal also with the conveyance of plague over sea.

Influence of age,

c.

Epidemiological problems.

Another aspect of the matter then presents itself, this being the question as to how far age, sex, race, cccupation, and habits, affect the liability of the individual to plague infection.

Lastly, we endeavour to complete our survey of the question of the spread of plague by considering a series of epidemiological problems which arise in connexion with the disease. Such problems present themselves (a) in connexion with the question of the occurrence of a prolonged interval between the importation of infection and the epidemic outbreak of the disease; (b) in connexion with the occurrence of atypical forms of the disease at the outset of an epidemic; (c) in connexion with the fatality of plague at different phases of an epidemic; (d) in connexion with the influence of meteorological conditions and seasonal variations in the severity of plague epidemics; (e) in connexion with the influence of insanitary surroundings on the severity of plague epidemics; (f) in connexion with the existence of an endemic focus of plague in the Himalayas, and the general question of the possibility of a recrudescence of the disease, apart from re-importation of the infection; and (g) in connexion with the theory that the plague bacillus requires to be acclimatised to the particular conditions obtaining in each locality before it can give origin to a plague epidemic.

Brief review of

II.-GENERAL SURVEY OF THE CHARACTER OF PLAGUE.

130. In conformity with our scheme, we begin with a general survey of the character former appearances of the disease. of plague in India and elsewhere.

Ever since the dawn of history we have records of epidemics of pestilential disease, associated with buboes and accompanied by a very high mortality. The pestilential disease characterised by "emerods in the secret parts," which is noted in the biblical records as striking down small and great among the Philistines in the time of the Judges; the pestilence which devastated Athens during the course of the Peloponesian War; the "Black Death" of the Middle Ages; the "Great Plague" of London; the fatal pestilential disease which was widespread in the Deccan and Western India, during

the latter part of the 17th Century; and the plague at Marseilles in the 18th Century; were probably all true bubonic plague. Coming to more recent times there is no doubt that, on the one hand, the "Oriental Plague" of Turkey, Egypt, and the Levant, in the early part of the 19th Century, and, on the other hand, the plague which occurred in Western India at various times from 1812 to 1837, were genuine bubonic plague; and, lastly, it seems, as we shall see, to be beyond question that the "Mahamari" which, from 1823 onwards, has been reported from the Himalayas, is to be identified with genuine plague.

131. The difficulty of discriminating plague from other diseases in pre-bacteriological Difficulties exdays is well brought out by the fact that, both in the case of the plague in Western perienced in formier epidemics in conIndia in the early part of the present century, and in the case of the mahamari of the nexion with the Himalayas, some observers were of opinion that the epidemics with which they were identification of dealing were epidemics, not of true bubonic plague, but of typhus, a disease which, atypical forms of both in its epidemiology, and in certain of its clinical characters, has many points of plague in man. similarity with plague. Again, the difficulties, in the absence of bacteriological investigation, of diagnosing certain forms of plague, are well illustrated by the uncertainty which has constantly prevailed as to whether cases of pneumonic affections and cases of high fever ending fatally, where such came under observation in association with cases of typical bubonic plague, were to be regarded as aberrant forms of the disease. We may refer here, for instance, to the fact that in the case of the plague, which raged in Kathiawar and the adjoining parts of Western India in the second decade of the 19th Century, there came under observation epidemics, which must, from their clinical description, have been epidemics of pneumonic plague, and which were, evea then, surmised to be such.*

occurrence of plague in animals.

132. The uncertainty that prevailed in pre-bacteriological days, as to what forms of Early surmises disease should be brought under the category of plague, extended also to diseases with regard to the Occurring among animals concurrently with epidemics of plague among men. Murrain among cattle, and mortality among rats, are frequently recorded as having occurred in association with plague epidemics, though it is remarkable that mortality among rats has not figured so prominently in the descriptions of past epidemics as might in accordance with recent experience have been expected. Perhaps the earliest passage which has been unearthed with reference to mortality among rats, is a passage from the Bhagavati Purana, quoted by Mr. Hankin in a memorandum on plague, enjoining upon the people that they should abandon their houses when rats "fall from the roof above, jump about, and die." Noteworthy also in this connexion is a passage cited from the biblical writings, where it is recorded that the Philistines, with a view to staying the plague which was devastating them, made golden images of their emerods and of "the mice that marred the land," and placed them with the Ark when they sent this back into the land of Judah. In the case of India, the occurrence of mortality among rats in the Himalayan villages, in association with the outbreak of plague among men, has been recorded from 1830 onwards. The Pali plague also was, it would seem, accompanied by rat mortality.

pre

the light of

133. Since 1894, when the plague bacillus was discovered, it has been possible to Classification of the confirm, or as the case might be to correct, the inferences arrived at in different types of bacteriological days with regard to the human and animal diseases which were plague in man in previously surmised to stand in association with plague. It has now been placed recent clinical beyond doubt, by accurate clinical study and bacteriological investigation, that the study and bacteriplague may in man assume any one of several very different clinical forms. It will ological investiconduce to the intelligibility of what will be said in the sequel with regard to the gation. spread of plague if we here very briefly characterise these different manifestations of

plague.

(1.) Plague, in its most typical variety, takes the form of bubonic plague. In this (1.) Bubonic type. form of plague the bacteria are carried by the lymph stream into the lymphatic glands, in particular into the lymphatic glands of the groin and the axilla-less frequently into those of the neck. The bacteria multiply there, and excite a considerable amount of swelling and inflammation, which manifest themselves in the form of a bubo. The development of this bubo is often associated with severe pain. Following closely upon--more rarely preceding-the development of the bubo,

* See Report on a disease which prevailed in Kattyawar in 1819-20, by Thomas Whyte, Esq., Bombay Medical and Physical Society, Vol. I., 1838, p. 167; and Report on a disease. which prevailed in the Zillah of Ahmedabad, in the years 1817-9, by J. Gilder, Bombay Medical and Physical Society, Vol. I., 1838, P. 190.