Islamic medical authorities were also always concerned with the significance of pharmacology and many important works such as the Canon have whole books devoted to the subject. The Muslims became heir not only to the pharmacological knowledge of the Greeks as contained in the works of Dioscorides, but also the vast herbalpharmacopoeias of the Persians and Indians. They also studied the medical effects of many drugs, especially herbs, themselves. The greatest contributions in this field came from Maghribi scientists such as Ibn Juljul, Ibn al-Salt and the most originalof Muslim pharmacologist, the 12th century scientist, al-Ghafiqi, whose Book of Simple Drugs provides the best descriptions of the medical properties of plants known to Muslims. Islamic medicine combined the use of drugs for medical purposes with dietary considerations and a whole lifestyle derived from the teachings of Islam to create a synthesis which has not died out to this day despite the introduction of modem medicine into most of the Islamic world.