The following-named drugs, classed by some authors as aro-matics, are not only active antiseptics and antispasmodics, but possess properties very similar to those of the more typical antiseptics, antipyretics, and anesthetics. These antiseptic properties of aromatic drugs are well known to modern science, and, what is of unique interest and significance, were perfectly familiar to the ancients, who could not possibly divine the scientific value of the virtues familiarized only by the crudest empiricism. In the custom of the Egyptians of embalming the dead we have a remarkable example of their divination of antisepsis in the perfumes and spices in which their dead were buried; and in the Christian Gospel we read of Nicodemus that he "brought a mixture of myrrh and aloes," and that "they took the body of Jesus, and wound it in linen cloths with the spices, as the manner of the Jews is to bury " (John xix. 39, 40).

Aromatics owe their virtues chiefly to the volatile oils they contain, which usually possess the characteristic odor and taste of the plants from which they are derived. These volatile oils are very numerous and extremely complex in their chemical structure, yet most have certain general features in common. The most widely distributed chemical constituents are terpenes, hydrocarbons of the aromatic series (C5H8)n. Many of them contain, in addition, phenols, aldehydes, ketones, alcohols, acids, esters, lactones, and oxides - a few contain nitrogen or sulphur, in which case their action is the more complex.

The chemical investigation of many of these oils has but just begun, and it is not improbable that in the isolation and purification of some of their constituents valuable therapeutic agents may be added to the physician's armamentarium. As they agree in their physiological action, in large part at least, the general effects are here summarized in brief. It should be remembered that many of these volatile oils are very widely employed in alcoholic liquors - creme de menthe, curagoa, maraschino, absinthe, kumtnel, chartreuse, etc., and therein add their effects to those of the alcohol.

General Action. - Locally, the volatile oils are stimulant and irritant. Internally, when taken in moderate quantities, they stimulate the digestive organs, and increase the activity of the circulation reflexly by stimulating the sensory ends of the vagus distributed to the mucous membrane of the stomach. The impression is conveyed to the center in the medulla, and from there transmitted to the accelerator nerves of the heart. Very large doses depress the heart's action, arresting it in diastole. The poisonous action of aromatics is similar to that of irritant narcotic poisons. The different oils will vary considerably according to the predominant constituent. Thus the purer terpenes containing oils are much less poisonous; while those containing phenols, as eugenol, thymol, etc., give the characteristic picture of carbolic acid poisoning. Most of them irritate the kidneys. Many of them are quite powerful local anesthetics, particularly if rich in ketones or phenols. They first stimulate, and then depress and exhaust, the nervous system. In diseased conditions they are used to increase peristalsis, to impart tone to the stomach, and to act as antiseptics; to arrest gastric and intestinal fermentation; to relieve pain wherever they are applied; and, by increasing the circulation in the brain and improving the condition of the gastro-intestinal tract, to relieve many of the phenomena of hysteria. The chief contraindication for the internal use of these drugs is the inflammation of the stomach, intestines, and kidneys.

The volatile oils and the various preparations of the aromatics should be given diluted in some proper vehicle.

A classification of this general group is not feasible. The individual members are so complex that a purely chemical classification, based on their many constituents, would be impractical. From the purely physical standpoint they may be divided into a few broad groups, as volatile oils, resins, oleoresins, gumresins and balsams, but this offers no clue to their therapeutic applications. The definitions of these groups may be found in another place in this book. The general grouping arrangement by many of the older writers on materia medica commends itself as practical, and the following series will be taken up: (1) Aromatic flavoring vehicles and carminatives, including mentha, coriandrum, anthemus, matricaria, anisum, marrubium, rosa, aurantium, caryophyllus, cardamomum, cinnamomum, foeniculum, myristica, carum, and a number of others; (2) condiments: piper, capsicum, zingiber, macis, etc.; (3) stimulants to the respiratory and genito-urinary mucous membranes; (4) volatile oils used as nervous stimulants; and (5) skin irritants and counterirritants, including turpentine and its allies, mustard and cantharides.

It should be borne in mind, in view of their composition, that any or all of them may be used as antiseptics, and, further, that some members of the group may be classed in any or all of the groups mentioned. Thus capsicum is a good counterirritant, an excellent aromatic carminative, a widely employed condiment, and may be of service in the late period of a chronic cystitis; others might be instanced. Thus the classification is purely convenient - it possesses no other value.