We suggested the possibility that learning compared to other occupations was more remunerative in Galen’s day than in our own, but there were poor physicians and medical students then, as well as those greedy for gain or who associated with the rich. Many doctors could not afford to use the rarer or stronger simples and limited themselves to easily procured, inexpensive, and homely medicaments.[555] Many of his fellow-students regarded as a counsel of perfection unattainable by them Galen’s plan of hearing all the different medical sects and comparing their merits and testing their validity.[556] They said tearfully that this course was all very well for him with his acute genius and his wealthy father behind him, but that they lacked the money to pursue an advanced education, perhaps had already lost valuable time under unsatisfactory teachers, or felt that they did not possess the discrimination to select for themselves what was profitable from several conflicting schools. [Sidenote: Medical discovery in Galen’s time.] Galen was, it has already been made apparent, an intellectual aristocrat, and possessed little patience with those stupid men who never learn anything for themselves, though they see a myriad cures worked before their eyes. But that, apart from his own work, the medical profession was not entirely stagnant in his time, he admits when he asserts that many things are known to-day which had not been discovered before, and when he mentions some curative methods recently invented at Rome.[557] [Sidenote: The drug trade.] Galen supplies considerable information concerning the drug trade in Rome itself and throughout the empire. He often complains of adulteration and fraud. The physician must know the medicinal simples and their properties himself and be able to detect adulterated medicines, or the merchants, perfumers, and _herbarii_ will deceive him.[558] Galen refuses to reveal the methods employed in adulterating opobalsam, which he had investigated personally, lest the evil practice spread further.[559] At Rome at least there were dealers in unguents who corresponded roughly to our druggists. Galen says there is not an unguent-dealer in Rome who is unacquainted with herbs from Crete, but he asserts that there are equally good medicinal plants growing in the very suburbs of Rome of which they are totally ignorant, and he taxes even those who prepare drugs for the emperors with the same oversight. He tells how the herbs from Crete come wrapped in cartons with the name of the herb written on the outside and sometimes the further statement that it is _campestris_.[560] These Roman drug stores seem not to have kept open at night, for Galen in describing a case speaks of the impossibility of procuring the medicines needed at once because “the lamps were already lighted.”[561] [Sidenote: The imperial stores.]