With the development of the traditional knowledge, the Arabians also fostered the process of distillation in connection with the hermetic art2). As early as the fourth century, the

1) Gebri Summa perfectionis magisterii. Ex bibliotheca vaticana exemplari. Gedani 1682. Lib. IV. p. 156 - 178. - Alchemize Gebri Arabis libri excud. Joh. Petrius Nuerembergensis. Bernae 1545. Lib. 2. cap. 12. - Torbert Bergmann, De primordiis chemiae. Upsala 1779. § 3D and § 4C. Editio Hebenstreit. Lipsiae 1787.

In addition to the works of Geber originally written in Arabian, a number of other works in Greek and Latin were until recently attributed to him. However, M. Berthelot has revealed the apocryphal character of these writings (Introduction a I'etude de la chimie des anciens et du moyen-age, Paris 1889, also Revue des deux mondes, September 15. and October 1. 1893). Among these are the Summa perfectionis magisterii which appears not to have been written before the middle of the fourteenth century.

2) Hermannus Conringius, De hermetica Aegyptiorum vetere et Para-celsiorum nova medicina libri duo. Helmstedt 1648. Lib. II, cap. 4.

Greek scholars Synesios of Ptolomais') and Zosimos of Panopolis2) had described the distilling apparatus and methods of the Egyptians. Aetius of Amida, a physician and writer who lived in Constantinople during the beginning of the sixth century, also described the preparation of empyreumatic oils by downward distillation (Destillatio per descensum)3). This as well as the upward distillation (Destillatio per ascensum) are reported by Geber. According to Porta's De destillatione of 15674) and other writers of the sixteenth century the Arabian physicians and alchemists introduced the condensing tube (Serpentina) for the better cooling of the distillate, and a kind of fractionation for the distillation of wine5).

Through the Arabians the medical and alchemistic knowledge of their times, also the mysticism of the hermetic6) art were transmitted to southwestern Europe. They were most prominent in the establishment and advancement of the theory of the transmutation of the metals, a theory which held sway for many centuries; also of the preparation of a quintessence from organic nature; and that of the much-sought lapis philo-sophorum. It was through this dogma that entered the medical and /theosophic realm of the middle ages, and through the search for these imaginary phantoms that the Arabians laid the foundation for the acquisition, by empirical methods, of practical chemical knowledge, of numerous facts and products. These in turn served as building stones with which the later chemical structure was erected. In the course of the ninth and tenth centuries the Arabians also established the universities at Cordova, Seville and Toledo. As centers of learning and research, these institutions were visited by seekers of knowledge from all countries for the purpose of studying medicine, magic and necromancy.

Torbert Bergmann, Historiae chemiae medium seu obscurum aevum. Editio Hebenstreit. Lipsiae 1787. Vol. 4.

Schmieder, Geschichte der Alchemie. Halle 1832. p. 85 et seq.

1) Synesii Tractatus chymicus ad Dioscoridem. In Fabricii Biblia grasca. Tom. 8.

2) "Et quid plura moramur? Unus Zosimos Panopolites libroII General History Of The Volatile Oils 7

II General History Of The Volatile Oils 8 loculente ad oculos nobis sistit antiquorum illa vasa destillationibus accommodata; postquam enim jussisset candidatos artis id agere ut ipsis ad manus esset mandassetque

II General History Of The Volatile Oils 12 tandem, ut clarius sese explicit, ipsas vasorum figuras appingit, quarum nonnullas licet rudiori manu exaratas ex bibliotheca regis christianissimi, et illa D. Marci Venetiis, libuit hie in gratiam curiosorum adjicere." (O. Borrichius, Hermetis Aegyptiorum et chemicarum sapientia, ab Hermanni Conringii animadversion/bus vindicata. Hafniae 1674. pag. 156.)

Detailed statements concerning Zosimos' account on distillation are also found in Hofers Histoire de la chimie. 2. Edit. 1866. Tom. 1. pp. 261-270.

8) AetiiII General History Of The Volatile Oils 13 Libri medicinales sedecim. Editio

Aldina 1533. fol. 10. - - See also footnote 4, p. 68.

4) See p. 44, footnote 7.

5) See. the illustration on p. 41.

6) The designation spagyric art, fromII General History Of The Volatile Oils 14 andcame into use during the time of Paracelsus, viz. in the first half of the 16. century.

Arabian medicine, and with it the art of distillation and the literature thereon, attained their greatest development during the period from the eighth to the eleventh centuries. However, but little definite information has come down to our own time concerning the numerous writers whose works have been perpetuated in their entirety or only in part. As a matter of fact, many of the works attributed to them are apocryphal and the real authors are not known with any degree of certainty. Not only is there a variation of one or more centuries in the dates attributed to them, but the opinions of historians concerning them is oftimes contradictory.

The Arabian writings which are of greatest importance in the documentary study of the history of distillation begin with the works of Geber about the ninth century. From the twelfth century on, the Arabian alchemists devoted themselves exclusively to the transmutation of the baser metals to the nobler ones, to the search for the lapis philosophorum.