jected to the cause, so their exhausted bodies are the fit soil where the disease first scatters its seed.

Mercurialis justly observes, that the true and principal fomes of pestilence is the poor miserable crowd of the lower orders, who not only by their confined way of living, but by their unwholesome food, are liable to be soonest infected, as well as to spread the disease most rapidly from one to another. He also remarks, that rulers should be especially careful about the state of the poor; above all things, to provide for them proper food and in sufficient quantity: for, he says, Galen and Avenzoar, and many historians inform us, that pestilence has frequently arisen from no other cause than a scarcity of corn, and unwholesome food.

Now seeing the most enlightened observers have borne testimony to the connexion I have noticed, and that it is therefore far from being hypothetical, I apprehend we may reasonably infer, that by the operation of such a cause, the human body is gradually brought into a state which is favourable to the attack of pestilential fever. Galen does not seem to have been far from the truth when he assigns to pestilence two causes: the one a great irregularity in the seasons, and consequent pestilential state of the air; the other a vitiated state of the human body, from corrupt and deficient food; by which means it is rendered liable to fever from very slight causes.* I must again advert to the article, from which I have already quoted, in the

Y

* Fuchsii Obs. p. 249.

Cyclopædia, where I think we may recognise the speculations of Dr. Bateman, that "when the bodies of the people happen to be predisposed to disease by want of food, or actually disordered by corrupted food; when the accumulation of filth, or the increase of marshy ground from rain or inundations, send forth miasmata in a most abundant and concentrated form, in consequence of a peculiar autumnal season, the most extensive epidemic diseases may be expected to arise, And we believe, that under such a combination of obvious circumstances, pestilence never fails to appear."

*

I consider these remarks to be a fair and conclusive winding-up of the argument.

On the subject of predisposition, a great deal more might be said, perhaps without wandering into the regions of conjecture.

In a connexion of events like those above stated with pestilence, there is surely nothing so marvellous as to draw for any uncommon degree of credulity, It is, perhaps, because so great a variety of circumstances, both past and present, local and general, individual and common, require to be taken into account, that we are at present in such a state of ignorance concerning the signs and causes of epidemic diseases. And therefore this uncertainty may be more owing to the limited nature of our observations, than to the difficulty of the pursuit, or the absolute impracticability of its object. If one man only looks to a cargo of merchandize for the cause, and another to a swarm of flies

* Loc. cit. verbo Epidemic.

or a distant earthquake; and if a third confines his attention to the present season, without taking a thought of the past; it may be expected that science will be as little advanced, and the public as little profited, as if each had forborne his observations entirely unless, indeed, the collected observations of all can be afterwards applied to the elucidation of some general principle. For my own part, when I consider the variable nature of the seasons, even in climates far less liable to changes than our own, I am not surprised that the phenomena of epidemics have been so uncertain, and their causes so much involved in doubt. Yet after taking into consideration even the few circumstances of the most notable epidemic plagues that have been handed down to us; and weighing the variety of causes which must necessarily unite to produce a pestilence, I can scarcely bring myself to think that we are so much in the dark with respect to the mode of its invasion as is commonly apprehended. I cannot therefore believe, that by merely guarding our coasts from diseases, the production of other climates and other nations of men, we are taking the most effectual means to preserve our own. For it appears to be in the highest degree probable, that when all those circumstances usually considered subordinate are present, as of soil and season, famine and filth, malignant epidemic fever, &c.; then plague will be produced without any foreign contagion: and it appears to be as clear that without the former, no foreign contagion need be dreaded. And although Dr. Bancroft has taken a very different view of the subject to that which I have entertained in the preceding pages, I avail myself with pleasure of his candid and comprehensive observation,

"that it is fortunate for mankind, that the communication of the contagion of plague depends upon the co-operation of so many favourable circumstances, and particularly on that of a suitable temperature, and of certain aptitudes and susceptibilities in the human subject."

I am therefore willing to hope, that an attention to the foregoing principles, with a wide and comprehensive survey of past and present seasons, past and present diseases, &c. will enable the intelligent physician to anticipate, and perhaps the wise politician to guard against future visitations.

SECT. V.

OF THE PROGNOSTIC SIGNS OF PESTIlence from DISEASES, AND GENERAL SUMMARY.

In this section, I propose to consider a few facts, which have not been noticed in Chapter VIII. As if to baffle research, the plague has not only sometimes occurred in a year and season of plenty, but at a time when other diseases have been remarkably rare. Hence, an invariable rule cannot be laid down on this point any more than on the other. Yet, I believe, in the majority of instances, that epidemic diseases usually mark its approach; and when these entirely cease, as they sometimes do, for several months before its appearance, it is not because the multitude is in the full enjoyment of health, but because the enemy is in secret collecting his forces, by undermining the vigor to strike a decisive blow. This state of calm, therefore, it is of great importance to bear in our remembrance,

when other circumstances shall have occurred to awaken reasonable fears.

Lord Bacon speaks of the small-pox, measles, and purple fever portending pestilence: and Sydenham's history confirms the observation. Schenkius observes, that in the year 1573, dysentery, measles, and purple fever were epidemic: and that for some time he presaged, that this malignant fever, which for nearly two years had overspread a considerable part of Europe, would pass into the true plague (in pestem apertissimam transituram,) and that he was not deceived in his opinion.

In the same manner, says Horstius, small-pox, measles, dysenteries raging epidemically, are very often forerunners of pestilence.* It would appear from Jackson's account of the plague in the empire of Morocco in 1799, that the small-pox is its usual precursor in that part of Africa. I have already noticed the connexion of the petechial or spotted fever with the plague, not only in this but in many other countries. Dr. Short remarks, "that in his previous histories of epidemic fevers may be seen the great affinity there is between the plague, spotted and pestilential fevers: that the last often turn to the first, as in 1568, 73, 97, 1598, 1601, 25, 26, &c. On the contrary, the plague often terminates in these fevers, as in 1556, 1564, 1666. Or if it is a Plague in one place, it is a spotted fever in another; as in 1564, 68, 74, 92, 97, 98. 1626, 35, &c."t

The spotted fever, therefore, would seem to be the

Horatius, p. 253, cited by Webster. † Short, vol. ii. p. 436.