As the prototype of a common flask, the figure of an ostrich2) is given (fig. 5); as that of a retort a goose (fig. 6) or a pelican3) (fig. 7). The shape of a bear served for a still (cuc-urbita)4) and head (alembicus) (fig. 8). An improved form of this simple distilling apparatus is found in the writings of Geber,5) and of Al-bucasis.6) The latter not only described glass distilling vessels, but also those prepared of glazed earthenware (fig. 9). He also described a kind of fractional distillation for the purpose of a "better condensation and separation of subtle spirits" by placing several alembices1) on top of one another (fig. 10).
1) Joannis Rhenani, Medici, Solis e puteo emergentis: sive disserta-tionis chymia technice practica, materia lapidis philosophici et clavis operum Paracelsi, qua abstrusa implicantur deficientia supplentur. Francofurti 1613. Pars 1. Theoremata chymio technica.
2) Phiala est vas vitreum ex ventre in modum sphaerae rotundo gra-cilem canalem in proceritatem emittens.
3) Pelicanus est vas circulatorium e figura pelicani pectus suum rostro fodientis, puliosque suos refarcientis nuncupatum, amplo ventre sensim in angustiis collum vergente, quod retortum et curvatum os rursus in ventrem immittit.
4) Cucurbita est vas plerumque turbinatum, in cucurbitae vel pyri formam utero turgescens. Cucurbita cum suo aiembico juncta e/'us-modi est.
5) Gebri Summa perfectionis magisterii. Gedani 1682. 6) See p. 25.
From the writings of Geber and Albucasis, also from those of the excellent physician and writer Rhases (El Razi) who lived in Bagdad during the 9. century, it becomes apparent that the Arabians distinguished as early as the 8. century between distillation over an open fire and from a water bath and an ash bath.2) Geber described both methods in detail.8)
For the purpose of better condensation, Costaeus of Lodi,4) a physician and alchemist of Bologna, recommended that the beak of the alembic be cooled by water (tigs. 11 and 12), also that the distillate be improved by the use of the water bath (balneum Mariaa) (fig. 13) and the sand bath (balneum arenas) (fig. 14).
1) Liber servitoris Bulchasin-Ben-aberazerin. Venetiae 1471. Lib. XXVII, p. 247. Modus alius cui vult destillare paucam aquam. Accipe ollam ex asre, et impie earn aqua, etpone super lanem ignis, etpone os ejus coopertorium perforatum foraminibus duobus vel tribus vet pluribus, aut paucioribus ventribus secundum quod poterit capere coopertorium ollae, et sint ventres ex vitro . ..
2) Das Buch der Geheimnisse des Abu Bekr Ben Zakaija Er-RazT. Fleischer's Catalog No. 266. Leipziger Stadtbibliothek. Codex K. 25.
3) Gebri Summa perfectionis magisterii. Cap. 50. Ex bibliotheca vati-cana exemptari. Gedani 1682.
4) Mesue, Simplicia et composita, et antidotarii novem posteriores sec-tiones adnotationes. Venetian 1602.
Among the writings left by the Arabians, the work of Albucasis prev'-ously mentioned probably contains one of the first and most striking descriptions of the manner of distillation and distilling apparatus.1)
From the 14. century on the practice of making distilled liquors increased very considerably. As a result the methods of distillation and the distilling apparatus, especially those parts employed for the condensation of the vapors, were greatly improved. The method of condensing the vapors, already well known to the Arabians, by passing the straight or bent tube of the alembic, or an elongation thereof wound into a spiral (wormtube, serpentina) through a tub of cold water was already in general use at that time for the distillation of wine and fermented plant juices. As examples of such distilling apparatus and methods, "die mancherley tyiihlungen der Teutschen und Welschen Weinbrenner", are described and illustrated in treatises on distillation of the first half of the 16. century, namely in those of Brunschwig, Ulstad, Ryff, and Lonicer. In these a distilling apparatus constructed with considerable skill is described. The helmet of the still and the outer condenser jacket were made of sheet copper. The head-like form of the expansion of the helm with the outer jacket, the lower open rim of which was tightly luted to the still, gave rise to the name of Mohrenkopf. The condensation was effected by a continuous flow of cold water through the outer jacket (fig. 15).
1) See p. 26.
The method of condensation derived from the Arabians was considered the most perfect for the distillation of spirit of wine (aqua vitae). The illustration of this apparatus was selected for the title page of the second volume of Brunschwig's Destillirbuch published in the year 1507 and is reproduced on page 41. Where the two upright serpentine connecting tubes (serpentinae) between the retorts (cucurbitae) and the receivers (recepta-cula) cross each other they pass through a condensing tube filled with cold water. The cooling effect thus produced is not sufficient for the condensation of all the vapor. The worm acts therefore, as a dephlegmator and increases the alcoholic strength of the distillate. This is correctly emphasized by Brunschwig.