Jabir ibn Hayyan

"The first essential in chemistry is that you should perform practical work and conduct experiments, for he who performs not practical work nor makes experiments will never attain to the least degree of mastery. But you, O my son, do experiment's so that you may acquire knowledge. Scientists delight not in abundance of material; they rejoice only in the excellence of their experimental methods."

"The most important collection of Arabic alchemical texts was supposedly written by Jabir ibn Hayyan, but... the writings, known collectively as the Jabirian Corpus, were the work of a Muslim sect... Isma'iliya... completed by 987, but probably compiled over... several generations. ...[H]ow much, if any ...is due to [Jabir] is not known."