Analysis of information sources in references of the Wikipedia article "発明の年表" in Japanese language version.
"The science of medicine has gained a great and extremely important discovery and that is the use of general anaesthetics for surgical operations, and how unique, efficient, and merciful for those who tried it the Muslim anaesthetic was. It was quite different from the drinks the Indians, Romans and Greeks were forcing their patients to have for relief of pain. There had been some allegations to credit this discovery to an Italian or to an Alexandrian, but the truth is and history proves that, the art of using the anaesthetic sponge is a pure Muslim technique, which was not known before. The sponge used to be dipped and left in a mixture prepared from cannabis, opium, hyoscyamus and a plant called Zoan."
"The science of medicine has gained a great and extremely important discovery and that is the use of general anaesthetics for surgical operations, and how unique, efficient, and merciful for those who tried it the Muslim anaesthetic was. It was quite different from the drinks the Indians, Romans and Greeks were forcing their patients to have for relief of pain. There had been some allegations to credit this discovery to an Italian or to an Alexandrian, but the truth is and history proves that, the art of using the anaesthetic sponge is a pure Muslim technique, which was not known before. The sponge used to be dipped and left in a mixture prepared from cannabis, opium, hyoscyamus and a plant called Zoan."