An illustration of the overbearing influence of authority, in giving celebrity to a medicine, or in depriving it of that reputation to which its virtues entitle it, might be furnished in the history of the Peruvian bark. This heroic remedy was first brought to Spain in the year 1632, where it remained seven years before any trial was made of its powers. An ecclesiastic of Alcala was the first to whom it was administered, in the year 1639; but even at this period, its use was limited, and it would have sunk into oblivion, but for the supreme power of the Roman church, by whose protecting auspices it was enabled to gain a temporary triumph over the passions and prejudices which opposed its introduction. Innocent the Tenth, at the intercession of Cardinal de Lugo, who was formerly a Spanish jesuit, ordered that its nature and effects should be duly examined, and on its being reported both innocent and salutary, it immediately rose into public notice. Its career, however, was suddenly arrested by its having unfortunately failed in the autumn 1652 to cure Leopold, Archduke of Austria, of a quartan intermittent: from this circumstance it had nearly fallen into disrepute. As years and fashion revolve, so have these neglected remedies, each in its turn, risen again into favour and notice; whilst old receipts, like old almanacks, are abandoned, until the period may arrive that will once more adapt them to the spirit and fashion of the times. Thus it happens, that most of the new discoveries in medicine have turned out to be no more than the revival and readoption of ancient practices. During the last century, the root of the male fern was retailed as a secret nostrum, by Madame Nouffleur, a French empiric, for the cure of the tapeworm: the secret was purchased for a considerable sum of money by Lewis XV. The physicians then discovered, that the same remedy had been administered in that complaint by Galen. The history of popular remedies for the cure of gout, also furnishes ample matter for the elucidation of this subject. The celebrated powder of the Duke of Portland, was no other than the _diacentaureon_ of Cœlius Aurelianus, or the _antidotos ex duobus centaureæ generibus_ of Ætius, the receipt for which a friend of his Grace brought with him from Switzerland; into which country, in all probability, it had been introduced by the early medical writers, who had transcribed it from the Greek volumes, soon after their arrival into the western parts of Europe.