Preface to the third volume.

The subjects of the present work, for reasons which prevail in many publications of the kind, have been inserted without reference to any particular arrangement or system. Those plants received the earliest place, the observations respecting which were earliest matured, and the drawings of which were first completed. Although this plan has been objected to in some foreign criticisms, it is the one pursued in several of the most extensive and useful botanical works of the day, which are accompanied with plates; and in periodical publications, or those which appear in successive numbers, it has more than one decided advantage. It gives time for all the figures to be completed at leisure, from perfect specimens, in proper and convenient seasons; at the same time that it does not necessitate premature and imperfect descriptions of their subjects, which must take place were an arrangement adopted, which might require the first insertion for plants not yet obtained or imperfectly examined. A systematic method may he adhered to in a work which is furnished for the press at once, but must occasion delay and imperfection in a periodical one.

As the American Medical Botany is terminated by the completion of its third volume, the opportunity is now afforded for taking a methodical view of its contents. Considered in a medicinal point of view, the subjects will be best classed as in systems of Materia Medica, by a reference to their leading properties or most striking modes of operating on the human system. In this light they may be arranged as follows.

Narcotics. Datura Stramonium, Conium maculatum, Cicuta maculata, Hyoscyamus niger, Nicotiana tabacum, Solanum dulcamara, Kalmia latifolia?
Astringents. Geranium maculatum, Statice Caroliniana, Arbutus Uva ursi, Rubus villosus, Rhododendron maximum, Nymphaea odorata, Myrica cerifera.
Tonics. Menyanthes trifoliata, Humulus Lupulus, Eupatorium perfoliatum, Coptis trifolia, Cornus florida, Gentiana Catesbaei, Aletris farinosa, Polygala rubella, Sabbatia angularis, Prinos verticillatus, Liriodendron tulipifera, Magnolia glauca.
Acrid stimulants. Arum triphyllum, Ictodes fcetidus, Ranunculus bulbosus.
Emetics. Lobelia inflata, Phytolacca decandra, Gillenia trifoliata, Veratrum viride, Sanguinaria Canadensis, Iris versicolor, Apocynum androsaemifolium, Dirca palustris, Euphorbia ipecacuanha, Euphorbia corollata. Erythronium Americanura.
Cathartics. Podophyllum peltatum, Juglans cinerea, Triosteum perfoliatum, Cassia marilandica.
Diaphoretics. Aristolochia serpentaria, Asarum Canadense, Xanthoxylum fraxineum, Solidago odora, Gaultheria procumbens, Laurus sassafras, Illicium Floridanum.
Diuretics. Juniperus communis, Pyrola Umbellata.
Expectorants. Polygala senega, Asclepias tuberosa.
Demulcents. Panax quinqefolium.
Anthelmintics. Spigelia marilandica.
External stimulants. Juniperus Virginiana, Rhus Vernix, Rhus radicans.

We avail ourselves of classification in the Materia Medica founded on the kind of operation which medicines exert on the human body, because there are seemingly no better characteristics by which to arrange them. But even this method is defective, because few medicines are simple in their operation, and of course most of them have claims to stand in more than one class. As examples, Tobacco, Henbane, Foxglove, and Opium are all of them properly placed by authors under the head of Narcotics. But of these, Tobacco is an emetic, Henbane a cathartic, Foxglove a diuretic, and Opium, while it checks all other excretions, is itself sudorific. Mercury, under its different forms and modes of administration, is capable of fulfilling half a dozen different intentions. The classifier of medicines then can do no more than to arrange them by their most obvious and well known properties, whatever these may be, leaving it understood that the name of a class is by no means fully descriptive of the character of its contents. [For a botanical arrangement of the plants, see the systematic index at the end of the volume. Not included. -Henriette.]

In forming a selection of sixty plants to be represented in this work, it has been endeavoured to choose those which are among the most interesting to botanists, at the same time that they possess claims upon the attention of medical men. It is by no means to be asserted that all these possess so decided an efficacy as to entitle them to the rank of standard medicines, or to make it advisable that pharmacopoeias should be swelled by their introduction. A part of them no doubt are eminently entitled to this distinction. Others are efficacious only in a second degree, but are still in use, and often advantageously so, in the hands of country practitioners. There are some of yet inferior efficacy, which, having formerly enjoyed a certain degree of medicinal notoriety, are inserted here with a view of defining their true character.

The progress of botanical students is much facilitated by the possession of correct drawings and dissections of a variety of dissimilar plants. In this country botanical figures, especially of American plants, are scarce, and accessible to but a small number of those who pursue this study. It is hoped that the present work may, in a certain degree, supply the deficiency, at least until the extension of natural science among us, and the increased number of botanical students, shall call forth and support works of greater magnitude.

A part of the plants contained in this work have never been figured in any botanical work. Others have been represented a great number of times; yet their importance, in a medical point of view, required their admission; and the figure being always made from an American specimen, it may, on this account, be not destitute of interest. Having arrived at the termination of the American Medical Botany, the author feels it incumbent on him to state, that he has at no time had cause to regret the undertaking of a work, which has furnished a most interesting employment for his leisure hours; and which has been honored with a patronage, greatly exceeding his anticipations.

American Medical Botany, 1817-1821, was written by Jacob Bigelow, M. D.