Under an edict of 1602, commissioners of the Inquisition were stationed at all the ports with instructions to seize all books by new authors and all new and enlarged editions of new books as they arrived and to allow no one to handle these until they had been inspected by representatives of the supreme council. Prohibited books were detained and burned. The regulations of the Inquisition had at this time rendered very difficult the carrying on of the printing and publishing business in Spain, with the result of very much decreasing the annual production of books. The requirements of scholars and readers could therefore be met only through the importation of books produced in France, Italy, or the Netherlands. The necessity, however, of securing for imported books, in addition to the inspection (onerous enough in itself) on the part of customs officials, an examination, volume by volume, by the representatives of the Inquisition, brought such serious burdens, expenses, and risks upon the business of the importers as to render this unprofitable. It is certainly the case that the circulation of books in Spain during the 17th century became very inconsiderable. An order issued in 1597 gives evidence of some consideration for the property of foreigners. When heretics came to trade, bringing books for their own use, the commissioner was instructed to examine these and to mark conspicuously and indelibly such as belonged to the prohibited list, so that they could be recognised by the faithful. The owners were warned, under heavy penalties, not to bring such books to the shore. In 1631, it was directed that “ships of England should be treated with gentleness so as not to cause offence.”[119] The instructions for the examination of vessels, whether Spanish or foreign, to guard against the introduction not only of prohibited books but of heretics, and to punish any infractions of the faith that might during the voyage have been committed either by the crew or passengers, were very precise and exacting. Under the fourth article of these instructions, a report is to be given as to what Christian doctrine and prayers of the Church have been recited at sea and what saints have been advocated and invoked in their necessities and perils. Under article six, it is ordered that all boxes and chests of the sailors and passengers were to be opened for evidence of heresy. Henry C. Lea, in a letter to the writer (under date of October 31, 1898) in regard to the effect of censorship on the literary interests of Spain, says: