general rules and principles of the art, and then goes on to treat of ancient music in all its forms; of music as Cardan knew and enjoyed it; of the system of counterpoint and composition, and of the construction of musical instruments. The Commentary on _Ptolemaei de Astrorum Judiciis_, the writing of which beguiled the tedium of his voyage down the Loire on his journey to Paris in 1552, is a book upon which he spent great care, and is certainly worthy of notice. Cardan's gratitude to Archbishop Hamilton for the liberal treatment and gracious reception he had recently encountered in Scotland, prompted him to dedicate this volume to his late patient. He writes in the preface how he had expected to find the Scots a pack of barbarians, but their country, he affirms, is cultivated and humanized beyond belief,--"and you yourself reflect such splendour upon your nation that now, by the very lustre of your name, it must needs appear to the world more noble and illustrious than at any time heretofore. What need is there for me to speak of the school founded by you at St. Andrews, of sedition quelled, of your country delivered, of the authority of your brother the Regent vindicated? These are merely the indications of your power, and not the source thereof." In the preface he also writes at length, concerning the horoscope of Christ,[251] in a strain of apology, as if he scented already the scandal which the publication of this injudicious performance was destined to raise. In estimating the influence of comets he sets down several instances which had evidently been brought to his notice during his sojourn in Scotland: how in 1165, within fourteen days of the appearance of a great comet, Malcolm IV., known on account of his continence as the virgin king, fell sick and died. Again, in 1214 two comets, one preceding and the other following the sun, appeared as fore-runners of the death of King William after a reign of forty-nine years. Perhaps the most interesting of his comments on Ptolemy's text are those which estimate the power of the stellar influences on the human frame, an aspect of the question which, by reason of his knowledge of medicine and surgery, would naturally engage his more serious attention. He tells of the birth of a monstrous child--a most loathsome malformation--at Middleton Stoney, near Oxford, during his stay in England,[252] and gives many other instances of the disastrous effects of untoward conjunction of the planets upon infants born under the influence of the same. He accuses monks and nuns of detestable vices in the plainest words, words which were probably read by the emissaries of the spiritual authority when the charge of impiety was being got up against him. In the _Geniturarum Exempla_ the horoscopes of Edward VI., Archbishop Hamilton, and Cardan himself have been already noticed; that of Sir John Cheke comes next in interest to these, and, it must be admitted, is no more trustworthy.