“The influence of fear and the depressing passions has also been considered as very powerful in predisposing persons to be affected with typhus contagion. There can be no doubt that fear has a tendency to produce a temporary depression of the physical powers; but, as has been already shown, there is no proof that persons of a naturally spare or weak habit of body, who are generally very sensitive, are more liable to fever than those of an ordinary constitution; this opinion must also be considered hypothetical. Indeed the facts, as far as our inquiries have enabled us to judge, seem to prove that the apprehension of fever, more particularly when it is not epidemic, is very rarely felt until the person is actually seized with the disease; for some cannot recollect of a single circumstance by which they could be exposed to contagion; and a considerable number of those who had undoubtedly been exposed to it were only made aware of the fact when it had been elicited by cross-examination. We are quite aware that cases may be brought forward of sensitive individuals who have been seized with fever soon after visiting a person labouring under the disease; but as this fact can be opposed with at least an equal number of persons who were destitute of fear, and yet caught it after an exposure to contagion, no conclusion whatever can be drawn from them. It must be observed, however, that though there is no proof that persons who are naturally weak in body or of a sensitive disposition are more susceptible of fever than those who are naturally vigorous and robust, yet that, during famine or commercial distress, poverty, by depressing the mind and lowering the physical status from insufficient aliment, does powerfully predispose a community to become affected with fever. This has been already shown in a former part of the essay, and has been again alluded to in order that the distinction might be made between an individual of naturally weak mental and physical stamina, and one who has been reduced to that state by deficient nutriment.” There appears to be little evidence on one side or the other in support of this last hypothesis, other than such as that cited from Dr. Davidson himself; but it is to be observed that the wet or bad seasons, which suspend agricultural industry and much labour in the towns, is usually of a character of itself to predispose to disease, if not to produce it; and that it does propagate it amongst all classes, high and low, in proportion to their exposure to it. It appears to be highly probable that the privation attendant on the stoppage of work, by diminishing the means for the purchase of fuel, of soap, &c., and in various ways by inducing lax habits of life, may increase the amount of exposure to and loss from the all-pervading cause.