It was with the gradual introduction of printed books during the beginning of the sixteenth century, that the treatises of the past became more and more the common property of those versed in science and reading. Up to this time, and even in later times, much that had been known to and practiced by individuals, was lost and had to be rediscovered.

This is true of the methods of distillation and of the apparatus used. Thus the apocryphal treatises of antiquity seem to show that the early method of primitive distillation was discovered by peoples widely separated both as to locality and time. Frequently there is no record of the direct transmittance of the art from one people to another. Wherever such transmittance may have taken place, it appears to have led less to a technical accomplishment than to a general stimulus.

1) Compare e. g. the quotation from Adam Lonicer on p. 49.

In the history of special peoples, cultural stages are found, in the evolution of their trades as well as in their literary productions, which are fundamentally related both to their material development and their political changes. Hence, the former can be fully understood only when considered in connection with the latter. Material and national welfare appear in history as a rule contemporaneously with intellectual and industrial achievement.

As to the discovery of natural products, the knowledge and separation of their components, and the utilization of these discoveries in materia medica and medicine, a new epoch was inaugurated, at the time of the reformation, by Paracelsus and others. With it the practice of the art of distillation was again conducted into proper channels. Thus it was made serviceable to materia medica and later to the trades. As a result there were produced in the course of time, an ever increasing number of important products. In addition to the production of alcohol, there should be mentioned the distilled aromatic waters which were highly prized and used in medicine for nearly three centuries. These were followed later by the distilled oils.

In the course of the twelfth and thirteenth centuries the art of distillation, which had been developed first by the Egyptians and later by the Arabians, was practiced but little.1) Hence, the methods and apparatus had been forgotten and had to be rediscovered. This reintroduction and rediscovery was furthered toward the end of the thirteenth and the beginning of the fourteenth centuries by the principal alchemists and physicians of that period, viz. by the Cardinal Vitalis de Furno of Basel (died 1327), the Bolognese teacher Thaddeus (Taddeo Alderotti, born 1215, died 1303), Arnoldus Villanovus (Arnold de Bachuone of Villeneuve or Villanova, born 1235, died 1312) and Raymondus Lullus (born 1235, died 1315). With this period, the distilling apparatus again found their way into the work shops of physicians and alchemists, became increasingly important and were accordingly improved. As the art of pharmacy was separated more and more from that of medicine, and as apothecary shops were established in larger numbers, the art of distillation gained admission to the laboratories attached to these shops. Carefully nursed, the art of distillation here developed into an important industry viz. that of the production of volatile oils.

1) Compare pp. 17, 24 and 26.

As a result, the progress made by the art of distillation henceforth is primarily to be sought in the literature on materia medica, as this had already been the case in the earlier Arabian medical treatises, viz. the antidotaries, e. g. the Grabaddin and other treatises. With the printing of books the number of medical treatises increased. Although they afford information concerning the time of introduction of drugs and distilled waters, and hence are of permanent interest to the student of materia medica, they are less satisfactory as sources of information concerning the production and introduction of distilled oils. Nevertheless, even for this purpose they constitute almost the only available literary sources.

The numerous works that came under consideration may be classed into three groups of equal importance: the anti-dotaries and the later dispensatories; the treatises on distillation which occupied a prominent position from the close of the fifteenth century to the close of the sixteenth century; and the price ordinances of various cities for spices and drugs which had come into use about the same time.

As already pointed out, the term "distilled" oils should not necessarily be interpreted in the same sense as we use it to-day The ancients had already known how to obtain fragrant oils by boiling seeds, fruits and other parts of plants with water also by cold and warm expression. These were used in the preparation of aromatic oils and ointments. However, all exact knowledge concerning the nature of these oils was wanting. Up to the seventeenth century this was equally true of the oils, obtained in all probability by the process of distillation, by the Indians, the Egyptians and later peoples. Neither was there any clear conception as to the distinction between fatty, expressed oils and distilled, aromatic oils.

Far into the middle ages, the designation "distillation" was used as a collective term for the preparation, according to the rules of the art, of plant and animal extracts and their supposed refinement. For this process of rectification, various methods and sources of heat also diverse utensils were used. The general term included such processes as maceration, digestion, straining, filtration, expression and sometimes even the processes of fermentation and decay.1) With the exception of turpentine or cedar oil those products mentioned in older literature as oils, or even as distilled oils, are to be regarded as fatty oils which have been aromatized and which were used for medicinal purposes and as unguents.

Whether the oils of rose, andropogon, and calamus, mentioned in the Ayur-Veda as distilled oils, were such in the modern sense of the term, can not be decided. The same doubt exists as to the oils of spike, rosemary and sage, as well as of other oils of later writers. As has already been pointed out, the art of distillation, known at an early period, may have fallen into disuse and have been forgotten.