He was equally skilful in pharmacy, but lowered his position by the practice, which would be unpardonable in a modern physician, of trafficking in secret remedies.
The investigations of the most recent of Talleyrand's biographers tend to show that the charges made against him of trafficking with the envoys have been overdrawn; but all his apologists admit that irregularities occurred.
This was followed by La Nuova Italia ed i Vecchi Zelanti (1881), another attack on the Vatican policy; and by his Vaticano Regio (1883), in which he accuses the Vatican of trafficking in holy things and declares that the taint of worldliness came from the false principles accepted by the Curia.
This unscrupulous proceeding, known as the Secularizations (February 1803), was carried out largely on lines laid down by Bonaparte and Talleyrand; and the latter is known to have made large sums of money by trafficking with the claimants of church lands.
He could not have become suddenly blind to the fallacy of the expectations derived from such a course; and all his life it had been his distinction to look above the transient and trafficking expedients of the professional politician.