"To conclude: the discovery of firearms. In 1205, the Emir Yaqub resorted already to artillery at the siege of Mahdiyya; in 1273, the Sultan Abu Yusuf used cannons at the siege of Sijilmasa. In 1342, two Englishmen, Lord Derby and Lord Salisbury, were present at the siege of Algeciras, defended by the Arabs in the same way. These travellers, having witnessed the effect of gunpowder, took this discovery back to their country. It was through them that the English made use of it, four years later, at Cressy. "In medical science, the Moslems followed Greek writers, and afterwards made most important progress. Nearly all the medical knowledge of Europe, at the epoch of the Renaissance, was borrowed from them. The remarkable progress they made in medicine, was in surgery; the description of maladies; _materia medica_; and pharmacy. They found out a quantity of methods, of which many--the use of cold water in typhoid fever, for instance--crop up again in modern times, after having been forgotten for centuries. "_Materia medica_ owes them numerous medicines, such as: cassia, senna, rhubarb, tamarinds, camphor, alcohol, ammonia, etc. They were the true creators of pharmacy. Most of the preparations still in use nowadays are due to them: syrups, emulsions, pomades, ointments, distilled water, etc. "Surgery also owes fundamental progress to the Arabs. Their work served as a basis for the teaching of Faculties of Medecine until quite recently. In the eleventh century of our era, they knew the treatment of cataract by the lowering or the extraction of the crystalline; lithotrity; the treatment of hemorrhage by irrigations of cold water; the use of caustics; setons; and cauterization by fire. Anesthesia, of which the principal discovery is supposed to be modern, seems to have been known to them. As a matter of fact, they speak favourably of the use of tare before undertaking painful operations, so that the patient may be put to sleep until "loss of consciousness and feeling" supervenes. "They had, likewise, implicit confidence in hygiene in medical treatment, and placed great reliance on the resources of Nature. Expectant medecine, which, at the present time, seems the last word of modern science, reasons exactly in the same way." (Dr. G. Le Bon, _La Civilisation des Arabes._) In the domain of ideas, the influence of the Moslems had perhaps still more valuable consequences. Jesus preached equality and fraternity, but Mohammad was lucky enough to realise both among the Believers during his lifetime.