6. _Passions of the mind._ These are looked upon by Dr. Fordyce to be among the less frequent causes of fever, though it is certain that they have been productive of multitudes of diseases, and even of sudden deaths; and Dr. Falconer, in his Prize Dissertation, ascribes to the passions very considerable effects in fevers, and even in the plague itself. “Contagious fevers (says he) afford strong instances of the influence of mental affections, both as prophylactics and remedies. The plague is a remarkable example, and the same reasoning extends to other disorders of a febrile, contagious nature. Fear, it is well observed by Dr. Cullen, by weakening the body, and thereby increasing its irritability, is one of the causes which, concurring with contagion, render it more certainly active, which he ascribes to its weakening effect on the body, by which its irritability is increased. Against this therefore he directs the mind to be particularly fortified, which is best done by giving people a favourable idea of the power of preservative means, and by destroying the opinion of the incurable nature of the disorder, by occupying the mind with business or labour, and by avoiding all objects of fear, as funerals, passing-bells, and any notice of the death of particular friends. Even charms might be used with good effect, could we promote a strong prepossession of their efficacy, either by the confidence they inspire, or by their engrossing the attention of the mind. It is no less certain, that a studious regard to promote hope and confidence in recovery, is equally necessary for the cure as for the prevention of such disorders. We know that contagious fevers have a peculiar tendency to diminish the energy of the brain, and of course to debilitate the whole system; and that this is especially the case with the plague, which produces the most considerable effects in weakening the nervous[82] system or moving powers, and in disposing the fluids to a general putrescency; and Dr. Cullen is of opinion that to these circumstances, as the proximate causes of the plague, regard should chiefly be had, both for the prevention and cure of this disorder. It must therefore be highly necessary, during the course of this disease, to attend to the support of the spirits, as on these the vital principles greatly depend; and they can by no means be so effectually kept up as by inspiring a confidence of recovery.” [82] “An intense head-ach, uncommon giddiness, and a sudden loss of strength, were the first complaints of those who were seized with this distemper.” (Russel on the Plague at Aleppo, p. 230.)