Fathers of Manila published it in the last edition of Father Blanco’s “Flora”; but neither this work nor those of Clain or Santa Maria are useful to a physician, nor are they as accurately written as works of a scientific character should be. From time to time superficial articles have appeared in the Manila papers regarding the virtues of some plant or other and these books and articles comprise the whole literature on the subject up to this time.

Some physicians regard with small favor the therapeutic application of plants by the Filipino “herb-doctors” (curanderos) as being entirely empirical. This disparagement is unjustified because in all the most rational and scientific remedies that we make use of, the first step towards the final development of their relative position among remedies is due to empiricism which is founded on daily experience, on observation of results obtained in specific cases, facts that are handed down from father to son for generations. The scientific explanation is lacking, but those first ideas frequently owing their origin to chance, or, perhaps, to superstition, have often been based upon the observation of facts which, although fortuitous, are none the less positive.

Many of the plants mentioned in this book are official in the Pharmacopœia of India and we see no reason why their use should be proscribed in the Philippines. Filipino physicians not only can but should employ many indigenous plants in their therapeutics; in many instances they would find them more useful than the exotics, which are not always fresh and are commonly reduced in strength by long keeping or damaged by some circumstance of voyage or climate. The price is another argument in favor of the use of native drugs. If the pharmacists would prepare extracts and keep on hand the crude drugs most in demand the public would gain a great advantage and the druggists be well repaid for their labor. Physicians and pharmacists will surely understand these advantages and when finally one considers that the patients generally prefer to be treated with native plants, I feel justified in the hope that their use will spread rapidly in the Philippines.

To employ therapeutically the drugs described in this work is not to experiment “in anima vilis,” as some would have us believe. To experiment is to employ unknown remedies of unknown virtues and properties.

In this treatise I am not attempting to fix the indications for this or that product, but simply make known the diseases in which the Filipinos and the natives of other countries employ the products. Any physician has a perfect right to prescribe these drugs, as have also the “curanderos” and even the laity, with this difference, however, that the physician is capable of observing results and guiding himself by the physiologic action of the drugs. His knowledge of the physiologic and anatomo-pathologic problems of the human body, will enable the physician to make scientific inferences that would be hidden from the common “curandero.”

As neither the Manila nor the provincial physicians keep these medicinal plants in stock, with the exception of those that are official in the European and American pharmacopœias, it will be necessary for the physician who wishes to use them, to busy himself with seeking them and laying in a sufficient stock to serve him when the opportunity presents itself. It is necessary to preserve them by drying and this is best done by exposing them several days to the fresh air in a dry place—for example, the corridors of the house—being careful not to expose them to the rays of the sun, in which latter event the fleshy and juicy plants which do not desiccate rapidly, putrefy or ferment.

A convenient way to get them is to visit the Binondo Square where there has been market for native drugs from time immemorial. The gardeners from the neighboring towns, especially those from Pasay and Singalon, regularly offer the plants for sale and will undertake to supply you with any that may not be on hand. Inasmuch as the common names of the plants lead to many mistakes and much confusion, it is indispensable to acquaint one’s self with the description of the plant and be sure that the actual product conforms in all respects to the description. For this purpose it is well to obtain flowering specimens, and bearing this fact in mind I have been careful to indicate the flowering season of each plant. By making excursions to the towns of San Mateo and Angono I have obtained an abundance of whatever I sought and at the same time have learned by talking with the mountaineers and “curanderos,” what uses they make of their plants. The “curanderos” know a great deal concerning these uses, but become very reticent as soon as they are questioned about them. Whether it is dread of ridicule or selfishness or fear that silences them, the fact remains that it is no easy matter to glean any useful facts from them. And yet by tact and friendliness one may elicit much more information from them than first impressions would lead one to hope.

Leaves should be gathered when fully developed, rejecting the old, dried and worm-eaten ones.

The best time to gather bark is one month before the period of inflorescence, when it is rich in sap. The flowers are best gathered when about half expanded. The fruit is gathered green or ripe according to the active principle sought. The seeds should always be mature.

Not all parts of the plant are equally provided with the active principle which may be localized in the root or the flower; or distinct principles may exist in different parts of the same plant. Therefore the part indicated, and only that part, should be employed.

In the root the active substance usually resides in the bark, sometimes in the parenchyma that envelopes the woody tissue and rarely in the woody tissue itself, as, for example, in “rhubarb” and “pareira brava.”

The stem bark is also a frequent seat of the active principle, of which the outer portion contains the greater amount, according to the valuable experiments of Howard.

Some plants owe their therapeutic importance to their wood, others to their leaves or flowers, and regarding the localization of the active principle in these parts we have nothing especial to indicate. The fruit, however, may have a pericarp consisting of mucilage, starch, sugar and gum, etc., while the seeds contain fatty matter, fixed or essential oils or alkaloids, as is the case with coffee and cacao. In view of these facts, we repeat that it is indispensable to use that part of each plant which I have indicated as applicable to a determined case or condition.

I earnestly hope that the physicians and pharmacists practising in the Philippines may undertake investigations and experiments regarding the therapeutic properties of the plants of my native land, and that my endeavors may have acted as a stimulus or inspiration to the loyal and earnest study of the subjects that are now awakening such interest, not only in Europe and America, but in India and Japan.

I should be pleased to receive notes, plants or reports of researches from any one interested in the subject matter of this book, and I shall consider it a pleasure, as well as a duty, to devote my forces, small as they may be, to aiding any one who may do me the honor to claim my assistance.

T. H. P. de Tavera.

Paris, April, 1892.