All the fevers which were called forth by the pestilence are, according to him, of the putrid kind; for they originate principally from putridity of the heart's blood, which inevitably follows the inhalation of infected air. The Oriental Plague is, sometimes, but by no means always occasioned by _pestilence_ (?), which imparts to it a character (_qualitas occulta_) hostile to human nature. It originates frequently from other causes, among which this physician was aware that contagion was to be reckoned; and it deserves to be remarked that he held epidemic small-pox and measles to be infallible forerunners of the plague, as do the physicians and people of the East at the present day. In the exposition of his therapeutical views of the plague, a clearness of intellect is again shown by Santa Sofia, which reflects credit on the age. It seemed to him to depend, 1st, on an evacuation of putrid matters by purgatives and bleeding; yet he did not sanction the employment of these means indiscriminately and without consideration; least of all where the condition of the blood was healthy. He also declared himself decidedly against bleeding _ad deliquium_ (_venae sectio eradicativa_). 2nd, Strengthening of the heart and prevention of putrescence. 3rd, Appropriate regimen. 4th, Improvement of the air. 5th, Appropriate treatment of tumid glands and inflammatory boils, with emollient, or even stimulating poultices (mustard, lily-bulbs), as well as with red-hot gold and iron. Lastly, 6th, Attention to prominent symptoms. The stores of the Arabian pharmacy, which he brought into action to meet all these indications, were indeed very considerable; it is to be observed, however, that, for the most part, gentle means were accumulated, which, in case of abuse, would do no harm: for the character of the Arabian system of medicine, whose principles were everywhere followed at this time, was mildness and caution. On this account, too, we cannot believe that a very prolix treatise by Marsigli di Santa Sofia, a contemporary relative of Galeazzo, on the prevention and treatment of plague, can have caused much harm, although perhaps, even in the fourteenth century, an agreeable latitude and confident assertions respecting things which no mortal has investigated, or which it is quite a matter of indifference to distinguish, were considered as proofs of a valuable practical talent.