There lived a man for whom Catherine cared more than for any of her children; his name was Cosmo Ruggiero.  He lived in a house belonging to her, the hotel de Soissons; she made him her supreme adviser.  It was his duty to tell her whether the stars ratified the advice and judgment of her ordinary counsellors.  Certain remarkable antecedents warranted the power which Cosmo Ruggiero retained over his mistress to her last hour.  One of the most learned men of the sixteenth century was physician to Lorenzo de’ Medici, Duc d’Urbino, Catherine’s father.  This physician was called Ruggiero the Elder (Vecchio Ruggier and Roger l’Ancien in the French authors who have written on alchemy), to distinguish him from his two sons, Lorenzo Ruggiero, called the Great by cabalistic writers, and Cosmo Ruggiero, Catherine’s astrologer, also called Roger by several French historians.  In France it was the custom to pronounce the name in general as Ruggieri.  Ruggiero the elder was so highly valued by the Medici that the two dukes, Cosmo and Lorenzo, stood godfathers to his two sons.  He cast, in concert with the famous mathematician, Basilio, the horoscope of Catherine’s nativity, in his official capacity as mathematicion, astrologer, and physician to the house of Medici; three offices which are often confounded.

At the period of which we write the occult sciences were studied with an ardor that may surprise the incredulous minds of our own age, which is supremely analytical.  Perhaps such minds may find in this historical sketch the dawn, or rather the germ, of the positive sciences which have flowered in the nineteenth century, though without the poetic grandeur given to them by the audacious Seekers of the sixteenth, who, instead of using them solely for mechanical industries, magnified Art and fertilized Thought by their means.  The protection universally given to occult science by the sovereigns of those days was justified by the noble creations of many inventors, who, starting in quest of the Great Work (the so-called philosophers’ stone), attained to astonishing results.  At no period were the sovereigns of the world more eager for the study of these mysteries.  The Fuggers of Augsburg, in whom all modern Luculluses will recognize their princes, and all bankers their masters, were gifted with powers of calculation it would be difficult to surpass.  Well, those practical men, who loaned the funds of all Europe to the sovereigns of the sixteenth century (as deeply in debt as the kings of the present day), those illustrious guests of Charles V. were sleeping partners in the crucibles of Paracelsus.  At the beginning of the sixteenth century, Ruggiero the elder was the head of that secret university from which issued the Cardans, the Nostradamuses, and the Agrippas (all in their turn physicians of the house of Valois); also the astronomers, astrologers, and alchemists who surrounded the princes of Christendom and were more especially welcomed and protected in France by