It is well known to every one the least versant in this part of Natural History, what a prodigious revolution has happened in the use of drugs, dyes, and gums, since the time of Galen, by the introduction of those Herculean medicines drawn from minerals. The discovery of the new world, besides, has given us vegetable medicines nearly as active and decisive as those of minerals themselves. Many found in the new world grow equally in the old, from which much confusion has arisen in the history of each, that will become inextricable in a few generations, unless attended to by regular botanists, assisted by attentive and patient draughts-men ignorant of system, or at least not slaves to it, who set down upon paper what with their eyes they see does exist, without amusing themselves with imagining, according to rules they have themselves made, what it regularly should be. One drawing of this kind, painfully and attentively made, has more merit, and promotes true knowledge more certainly, than a hundred horti sicci which constantly produce imaginary monsters, and throw a doubt upon the whole. The modern and more accurate system of botany has fixed its distinctions of genus and species upon a variety of such fine parts naturally so fragil, that drying, spreading, and pressing with the most careful hands, must break away and destroy some of those parts. These deficient in one plant, exiting in another in all other respects exactly similar, are often, I fear, construed into varieties, or different species, and well if the misfortune goes no farther. They are precisely of the same bad consequence as an inaccurate drawing, where these parts are left out through inattention, or design. After having bestowed my first consideration upon these that make a principal figure in ancient history, which are either not at all or imperfectly known now, my next attention has been to those which have their uses in manufactures, medicine, or are used as food in the countries I am describing. The next I have treated are the plants, or the varieties of plants, unknown, whether in genus or species. In these I have dealt sparingly in proportion to the knowledge I yet have acquired in this subject, which is every day increasing, and appears perfectly attainable. The history of the birds and beasts is the subject which occupies the next place in this Appendix; and the rule I follow here, is to give the preference to such of each kind as are mentioned in scripture, and concerning which doubts have arisen. A positive precept that says, Thou shalt not eat such beast, or such bird, is absolutely useless, as long as it is unknown what that bird and what that animal is.