In the course of centuries various more or less independent branches have separated from the common trunk of natural science and have made a history of their own. This is true of the subject presented in this treatise. To be sure a fairly exact knowledge of those plant products, which are termed volatile oils, has been gained only in recent periods. Nevertheless the nature and value of these substances does not appear to have escaped the observation of the oldest peoples. It seems almost certain that not only the grace and vivid coloring of the flowers but also the fragrance of the vegetation in southern Asia must have aroused the curiosity of man, fully as much as did the utilization of the plants for the purpose of food and clothing. Indeed, those plants and plant products that were conspicuous on account of their aromatic odor and taste, seem to have attracted the attention of man in a special degree. These very properties seem to have induced him to use them and to seek proper methods for their cultivation and preservation.

It is true that the oldest documents pertaining to the history of the beginning of human industry have recorded only the most primitive methods for the preparation of implements that were used in the chase, the cultvation of the soil, and for the collection and preparation of foodstuffs and other useful products. Nevertheless it may not be amiss to suppose that the exigencies of self-preservation and of wellbeing at an early period caused man to utilize fire not only for the preparation of foodstuffs but for various other purposes. It may have required long periods of time before fire was used for the preservation of perishable foodstuffs, for the separation of pleasant substances from disagreeable ones: so, e. g., the distillation of the "spirit of wine" from the wine itself; the separation of the "subtle principle", the aroma, from spices which were among the earliest articles of barter and commerce during antiquity; and which as products of nature agreeable to the gods, were offered as sacrifices in religious ceremonies, and were also used in the embalming of the dead.

It is especially this use of spices and of aromatic plant products by the priests, those promotors and supporters of natural science during antiquity, that renders it probable that their knowledge was early applied to the production, and preparation of the spices which were used in the sacrifices and in embalming. Whether a beginning in the preparation of the aromatic principles of plants, our modern volatile oils, was made previous to early Hindoo and Egyptian civilization, does not become apparent from the oldest documents. Even the Bible, which gives so much information concerning the customs of the jews, makes no other statements than those pertaining to the spices and aromatics used in various countries. The early preparation and utilization of the more common metals would indicate that furnaces and other apparatus for heating were used in a variety of ways. One may suppose, therefore, that they were gradually used in primitive attempts to separate the spirit from wine, from other fermented fruit juices and honey; also the aromatic principles from spices, balsams and oleoresins. These crude experiments may be considered as constituting the first stages in the art of distillation.

The Egyptians, owing to the continuity of their early and highly developed civilization and to the preservation of their monuments and literary productions, are generally considered as standing at the portals of history. With reference to time, however, the Chinese and Aryans are probably the oldest peoples. These races, with whom civilization seems to have had its beginning, lived in central and southern Asia, a mountainous district favored with a mild climate and a luxuriant vegetation rich in useful and spicy products. Our knowledge of the peoples who first occupied this wide territory is but legendary. Concerning their industrial and technical accomplishments but little definite information has come down to us. These Chinese and

Indians may have developed considerable dexterity in industrial pursuits and may even have accomplished much in the scientific realm. Their attitude of exclusiveness, however, toward the outside world and their secrecy have prevented them from exerting a lasting influence on other nations. The oldest documents that throw light on their early scientific accomplishments are the Ayur-Veda (Book of the Science of Life) by Charaka and Susruta.1) As is the case with so many writings of early antiquity, nothing definite is known with regard to the age of these documents. It is possible that they are traditions reduced to writing at a rather late time.2) From this work it becomes apparent that the Indians were acquainted with primitive apparatus for distillation, with fermentation and the products obtained by distillation. Of "distilled oils", those of rose, schoenus (andropogon), and calamus are mentioned.3) Whether these oils are "distilled" in the modern sense of this term can not be ascertained.

From documents of the old Persians it would seem that they also were acquainted with the process of distillation and hence with distilling apparatus.4)

With regard to the Egyptians, however, whose history goes back as far as 4000 B. C, we have definite information concerning the early development of industry, art, and science. Their commerce, which extended as far as India, Babylonia,

1) Susruta's Ayur-vedas, id est medicinae systema a venerabili D'han-vantare demonstratum a Susruta discipulo compositum. Nunc primum ex Sanscrita in Latinum sermonem vertit, introductionem, annotationes et rerum indicem adjecit Dr. Fr. Hessler, Erlangae 1844.

The Susruta, or System of medicine, taught by Dhanvantari and composed by his disciple Susruta. Published by Sri Madhusudana-Gupta, Prof. fo medicine at the Sanscrit College at Calcutta. Calcutta 1835. 2 Vol.

2) Lassen, Indische Altertumskunde. 1. ed., vol. 2, 551.