Jabir ibn Haiyan and Al-Idrisi

Jabir Ibn Haiyan, the alchemist Geber of the Middle Ages, is generally known as the father of chemistry. Abu Musa Jabir Ibn Hayyan, sometimes called al-Harrani and al-Sufi, was the son of the druggist (Attar). The precise date of his birth is the subject of some discussion, but it is established that he practiced medicine and alchemy in Kufa around 776 A.D. He is reported to have studied under Imam Ja'far Sadiq and the Ummayed prince Khalid Ibn Yazid. In his early days, he practiced medicine and was under the patronage of the Barmaki Vizir during the Abbasid Caliphate of Haroon al-Rashid. He shared some of the effects of the downfall of the Barmakis and was placed under house arrest in Kufa, where he died in 803 A.D.
Jabir's major contribution was in the field of chemistry. He introduced experimental investigation into alchemy, which rapidly changed its character into modern chemistry. The ruins of his well-known laboratory remained after centuries, but his fame rests on over 100 monumental treatises, of which 22 relate to chemistry and alchemy. His contribution of fundamental importance to chemistry includes perfection of scientific techniques such as crystallization, distillation, calcination, sublimation and evaporation and development of several instruments for the same. The fact of early development of chemistry as a distinct branch of science by the Arabs, instead of the earlier vague ideas, is well-established and the very name chemistry is derived from the Arabic word al-Kimya, which was studied and developed extensively by the Muslim scientists.
Perhaps Jabir's major practical achievement was the discovery of mineral and other acids, which he prepared for the first time in his alembic (Anbique). Apart from several contributions of basic nature to alchemy, involving largely the preparation of new compounds and development of chemical methods, he also developed a number of applied chemical processes, thus becoming a pioneer in the field of applied science. His achievements in this field include preparation of various metals, development of steel, dyeing of cloth and tanning of leather, varnishing of water-proof cloth, use of manganese dioxide in glass-making, prevention of rusting, lettering in gold, identification of paints, greases, etc. During the course of these practical endeavours, he also developed aqua regia to dissolve gold. Jabir laid great stress on experimentation and accuracy in his work.
Based on their properties, he has described three distinct types of substances. First, spirits i.e. those which vaporize on heating, like camphor, arsenic and ammonium chloride; secondly, metals, for example, gold, silver, lead, copper, iron; and thirdly, the category of compounds which can be converted into powders. He thus paved the way for such later classification as metals, non-metals and volatile substances.
Although known as an alchemist, he did not seem to have seriously pursued the preparation of noble metals as an alchemist; instead he devoted his effort to the development of basic chemical methods and study of mechanisms of chemical reactions in them- selves and thus helped evolve chemistry as a science from the legends of alchemy. He emphasized that, in chemical reactions, definite quantities of various substances are involved and thus can be said to have paved the way for the law of constant proportions.
A large number of books are included in his corpus. Apart from chemistry, he also contributed to other sciences such as medicine and astronomy. His books on chemistry, including his Kitab-al-Kimya, and Kitab al-Sab'een were translated into Latin and various European languages. These translations were popular in Europe for several centuries arid have influenced the evolution of modern chemistry. Several technical terms devised by Jabir, such as alkali, are today found in various European languages and have become part of scientific vocabulary. Only a few of his books have been edited and published, while several others preserved in Arabic have yet to be annotated and published.
Doubts have been expressed as to whether all the voluminous work included in the corpus is his own contribution or it contains later commentaries/additions by his followers. According to Sarton, the true worth of his work would only be known when all his books have been edited and published. His religious views and philosophical concepts embodied in the corpus have been criticized but, apart from the question of their authenticity, it is to be emphasized that the major contribution of Jabir lies in the field of chemistry and not in religion. His various breakthroughs e.g., preparation of acids for the first time, notably nitric, hydrochloric, citric and tartaric acids, and emphasis on systematic experimentation are outstanding and it is on the basis of such work that he can justly be regarded as the father of modern chemistry. In the words of Max Mayerhaff, the development of chemistry in Europe can be traced directly to Jabir Ibn Haiyan.

Al-Idrisi
Abu Abdullah Muhammad Ibn Muhammad Ibn Abdullah Ibn Idris al-Qurtubi al-Hasani, was born in Ceuta, Spain, in1099 A.D. He was educated in Cordova. Later he traveled far and wide in connection with his studies and then flourished at the Norman court in Palermo. The date of his death is controversial, being either 1166 or 1180 A.D.
His major contribution lies in medicinal plants as presented in his several books, especially Kitab al-Jami-li-Sifat Ashtat al-Nabatat. He studied and reviewed all the literature on the subject of medicinal plants and formed the opinion that very little original material had been added to this branch of knowledge since the early Greek work. He, therefore, collected plants and data not reported earlier and added this to the subject of botany, with special reference to medicinal plants. Thus, a large number of new drug plants, together with their evaluation, became available to the medical practitioners. He has given the names of the drugs in six languages: Syrian, Greek, Persian, Hindi, Latin and Berber.
In addition to the above, he made original contributions to geography, especially as related to economics, physical factors and cultural aspects. He made a planishere in silver for King Roger II, and describes the world in Al-Kitab al-Rujari (Roger's Book), also entitled Nuzhat al-Mushtaq fi Ikhtiraq al-Afaq (The delight of him who desires to journey through the climates). This is practically a geographical encyclopedia of the time, containing information not only on Asia and Africa, but also Western countries.
Al-Idrisi, later on, also compiled another geographical encyclopaedia, larger than the former entitled Rawd-Unnas wa-Nuzhatal-Nafs (Pleasure of men and delight of souls) also known as Kitab al-Mamalik wa al-Masalik.
Apart from botany and geography, Idrisi also wrote on fauna, zoology and therapeutically aspects. His work was soon translated into Latin and, especially, his books on geography remained popular both in the East and the West for several centuries.