The government of the Marques de las Amarillas commenced on the 10th of November, 1755; and he immediately devoted himself to the task of reforming many of the abuses which had doubtless crept into the administration of public affairs during the reign of his trafficing predecessor. Valuable mineral deposits were discovered in New Leon, whose veins were found so rich and tempting that crowds of miners from Zacatecas and Guanajuato flocked to the prolific region. Great works were commenced to facilitate the working of the drifts, but the wealth which had so suddenly appeared on the scene as if by magic, vanished amid the interminable quarrels and law suits of the parties. Many of the foremost adventurers who imagined themselves masters of incalculable riches were finally forced to quit their discoveries, on foot, without a dollar to supply themselves with food. In 1759 a general mourning was proclaimed in Mexico for the queen of Spain, Maria Barbara of Portugal, who was speedily followed to the tomb by her husband Ferdinand VI. His brother Charles III. ascended the throne, and whilst the mingled ceremonies of sorrow and festivity for the dead and living were being performed in Mexico, the worthy viceroy was suddenly struck with apoplexy which his physicians thought might be alleviated by his residence in the healthful and lower regions of Cuernavaca. But neither the change of level nor temperature improved the condition of the viceroy, who died of this malady on the 5th of January, 1760, in the beautiful city to which he had retreated. He was a remarkable contrast to his predecessor in many respects, and although he had been viceroy for five years, it is stated, as a singular fact in the annals of Mexico, that he left his widow poor and altogether unprovided for. But his virtuous conduct as an efficient minister of the crown had won the confidence and respect of the Mexicans who were anxious to succor those whom he left dependant upon the favor of the crown. The liberality of the archbishop Rubio y Salinas, however supplied all the wants of the gentle Marquesa, who was thus enabled to maintain a suitable state until her return to the court of Spain, where the merits of her husband, as a Spanish soldier in the Italian wars, doubtless procured her a proper pension for life. As the death of the Marques de las Amarillas was sudden and unexpected, the king of Spain had not supplied the government with the usual _pliego de mortaja_, or mortuary despatch, which was generally sent from Madrid whenever the health of a viceroy was feeble, so as to supply his place by an immediate successor in the event of death. The AUDIENCIA, of course, became the depository of executive power during the interregnum, and its dean Don Francisco Echavarri, directed public affairs, under its sanction, until the arrival of the viceroy, _ad interim_, from Havana. DON FRANCISCO DE CAGIGAL, XLIII. VICEROY OF NEW SPAIN. 1760--APRIL TO OCTOBER.