The commencement, however, of his reign was such as by no means prognosticated its subsequent transition. The sudden change of his conduct, the astonishing mixture of imbecility and presumption, of moral turpitude and frantic extravagance, which he afterwards evinced; such as rolling himself over heaps of gold, his treatment of his horse Incitatus, and his design of making him consul, seem to justify a suspicion that his brain had actually been affected, either by the potion, said to have been given him by his wife Caesonia, or otherwise. Philtres, or love-potions, as they were called, were frequent in those times; and the people believed that they operated upon the mind by a mysterious and sympathetic power. It is, however, beyond a doubt, that their effects were produced entirely by the action of their physical qualities upon the organs of the body. They were usually made of the satyrion, which, according to Pliny, was a provocative. They were generally given by women to their husbands at bed-time; and it was necessary towards their successful operation, that the parties should sleep together. This circumstance explains the whole mystery. The philtres were nothing more than medicines of a stimulating quality, which, after exciting violent, but temporary effects, enfeebled the constitution, and occasioned nervous disorders, by which the mental faculties, as well as the corporeal, might be injured. That this was really the case with Caligula, seems probable, not only from the falling sickness, to which he was subject, but from the habitual wakefulness of which he complained. (294) The profusion of this emperor, during his short reign of three years and ten months, is unexampled in history. In the midst of profound peace, without any extraordinary charges either civil or military, he expended, in less than one year, besides the current revenue of the empire, the sum of 21,796,875 pounds sterling, which had been left by Tiberius at his death. To supply the extravagance of future years, new and exorbitant taxes were imposed upon the people, and those too on the necessaries of life. There existed now amongst the Romans every motive that could excite a general indignation against the government; yet such was still the dread of imperial power, though vested in the hands of so weak and despicable a sovereign, that no insurrection was attempted, nor any extensive conspiracy formed; but the obnoxious emperor fell at last a sacrifice to a few centurions of his own guard.