A few years later, another distinguished Dutch antiquary, Spon of Leyden, published an account of a third tablet, similar in character to the two described by Schmidt;[425] and he suggested that they were engraved stones, which the ancient pharmacopolists used as lids for covering the jars or boxes in which their ointments, oils, or collyria were kept.[426] Subsequently, during the currency of the last century, Chishull,[427] Caylus,[428] Walch,[429] Saxe,[430] and Gough,[431] published accounts of various other stones, analogous in their character to the two first discovered at Nymegen. And, through the labours and interpretations of these and other authors, it came at last to be generally admitted among antiquaries, that the nature of the legends upon the stones in question,—the incuse and retrograde form of their inscriptions,—and the localities in which they were found, all proved them to be medicine-stamps, employed for the purpose of marking their drugs, by the Roman doctors, who (some sixteen or seventeen centuries ago) practised at the various stations throughout Europe, that were in those olden times occupied by the colonists and soldiers of Rome. Latterly, since the beginning of the present century, various additional examples of similar Roman medicine-stamps have been discovered at different old Roman towns and stations in France, Germany, etc., and described by Tochon,[432] Sichel,[433] Duchalais,[434] Dufour,[435] and others. These Roman medicine-stamps all agree in their general characters. They usually consist of small quadrilateral or oblong pieces, of a greenish schist and steatite, engraved on one or more of their edges or borders. The inscriptions are in small capital Roman letters, cut retrograde and intagliate (like the letters on modern seals and stamps), and consequently reading on the stone itself from right to left, but making an impression, when stamped upon wax or any other similar plastic material, which reads from left to right. The inscriptions themselves generally first contain (and that repeated on each side) the name of the medical practitioner to whom the stamp pertained; then the name of some special medicine, or medical formula; and, lastly, the disease or diseases for which that medicine was prescribed. In a few instances, the modes and frequency of using the medicine are added. In some instances, the designation of the medicine, and of the disease for which it is intended, are alone given. Perhaps still more frequently, when the number of items is limited, the name of the medical practitioner only appears, along with the name of some special medicinal preparation or remedy prepared or sold by him. And sometimes the stamps present merely the appellation of the medicine alone, without either the name of the practitioner who vended it, or the name of the disease against which it was supposed to be efficacious.