Ander Theil des Schatzes Euonymi von allerhand kunstlichen und bewerten Qlen, wasseren und heymlichen Arzneyen, sampt ihrer ordentlichen bereytung und dienstlichen Figuren. Erstlich zusammen getragen durch Herrn Doctor Cunrat Gesner, Demnach [von Caspar Wollfen der Arzneyen Doctor. Zurich; in Latin beschrieben und in Truck gefertiget, jetzt aber newlich von Johann Jacobo Niischeler Doctoren, in Tiitsche Sprach ver-tolmetschet. 1583.

Compared with Brunschwig's treatise which had appeared 50 to 65 years earlier, Gesner's treatises reveal a decided advance in the technique of distillation, also in his knowledge of volatile oils. The first German edition of 1555 contains several chapters "on distilled oils" (pp. 212 - 249) and on "balsams" and other mixed oils2) (pp. 249 - 273). The distillation of a

1) This famous book went through a considerable number of editions in the course of a century or more and was evidently very widely read. The English translation, by Morvyng, appeared in 1559 under the title: New book of distillation called the treasure of Euonymus. London 1559, 1564 - 1565. A French translation appeared at Lyons in 1555.

The nom-de-plume chosen by Gesner was most likely derived from evonymus = Spindle tree (prik-wood) and philiatros, qifos largos = friend of science of medicine.

2) Literally: "Balsamen und anderen kostlichen krefftigen und artig zusammen gesetzten Oelen." number of oils, viz.: of the oils of lavender, rosemary, rue, cinnamon, cloves, nutmeg and others, is described, and the description accompanied with cuts of the apparatus to be used; also the distillation of juniper berries and juniper wood by destillatio per ascensum and destillatio per descensum. (pp. 217 and 247). Of the oils of gum resins, oleoresins and resins, those of ammoniac, benzoes, galbanum, labdanum, myrrh, opopanax, liquid storax and styrax calamita, mastic and turpentine are described. The oils from guaiac wood and sandal wood and from several other woods and barks are mentioned (pp. 244 - 247) and their distillation described.

The second part published in 1583, which may be regarded as a new edition brought up to date, contains much the same material and illustrations.

To what extent Gesner's conception of the nature of the products of distillation was influenced by tradition, becomes apparent from the preface of the first German edition in which he praises the art of distillation as a means to obtain from medicaments

"Die aller re/nest, edlest, krefftigst und durchtringest substanz, so die arzet nennen das fuenfft waesen (quinta essentia), von der unreinen, groben, yrdischen, unnuetzen und untaugliche substanz abgesuenderet und aus-gezogen werden."

And further on he says:

"Demnach so findest du in diesem buche vergriffen die fuertraefflichen und tugendreychen stuck und arznyen, so die kuenstler, arzet und Alchy-misten als sundere geheimnuessen und secret der natur, mit grossem fleyss verborgen und verhalten habend: als da sind die wohlriechenden wasser, die oel die aus kreueteren, gewaechsen, bluemen, fruechten und wurzeln gezogen und separirt werden."

A better understanding of the volatile oils themselves is revealed in the following passage from the first volume (p. 103):

"Lass ordentlich destillieren in waermer aeschen, von der absuenderung und scheidung des oels vom erdreych, so wirst du saehen von den selbigen materi, so auf diese art destillirt wirdt, ein feyn lauter, schoen und klaar wasser und oel herabfliessen, welches in im hatt de lufft oder des luffts eigenschafft, und das wasser, das ist die substanz u-nn das waesen, so das Element lufft und wasser in im hatt."

However, the confusion of ideas concerning distilled oils on the one hand and aromatized fatty oils on the other still manifests itself repeatedely in the writings of Gesner and Cordus.

Thus in the chapter on "distilled oils" three and even four methods for the preparation of one and the same oil are described. Among these are found not only the method of distillation proper, but that of infusion and digestion (circulation) with fatty oils, e. g. rose oil (pp. 224 and 236), lavender oil (p. 337), marjoram, myrrh and other oils (p. 332).

According to Gesner's directions a preliminary moistening of the material to be distilled with spirit of wine (aqua vitae) is recommended. The oils are designated as a „feiste Feuchtig-keit" which is inherent in the herbs, flowers and roots. Flowers which have a delicate odor, such as roses, jasmine, etc, are packed in layers into the still, each layer being separated from the next by a similar layer of perfectly odorless flowers or leaves. The latter are to take up the aroma and to transfer it to the distillate.

In addition to many admirable directions, Gesner's writings contain descriptions of methods of distillation which reveal a complete absence of a clear distinction between aromatized fatty and distilled oils.

Thus among other descriptions, Euonymus Philiatrus gives the following directions for the preparation of distilled oils of several spices, viz. from cloves, nutmeg, mace, benzoes, storax, myrrh, safran etc.

"Die Specerei wird grob gepulvert, dann mit aqua vitas durchfeuchtet und in den glasine retorte gethan, und bei gelinder Warme destillirt. Wenn das 61 anfahrt zu fliessen, so nimm die materi der specereyen aus dew kolben und thus in ein sacklin, welches wohl verbunde sye mit einem faden, und trucks aus under einer prassen. Also dass du beide blach der prassen wohl heiss machest. Und also gebiirt es sich das ausgetruckt ol destilliren, rectificiren und circuliren, damit auff diese weis das rein lauter ol werde geschieden von der groben yrdischen materi. Demnach mag man wohl widerumb die hapffen putrificiren und digeriren mit dem vorgemeltem aqua vitae, so von anderem abgesunderet worden. Unn zum letzten widerumb destilliren."

Thus the distillation was interrupted at the beginning, the fatty oil aromatised with the volatile oil was expressed, and the volatile oil separated from the aromatised fatty oil by distillation.1)