(Marar, to grow bitter. Heb.) Bitters. Bitterness is a simple perception which cannot be defined, but must be referred to experience. What is the nature of the substances possessed of it, in a chemical view, we cannot determine, and consequently cannot explain.
The bitter is so often united with the astringent, the tonic, or the aromatic principle, that it has not been usual, in therapeutical authors, to distinguish the effects of the pure bitter. In this place, it must be considered as unconnected with either; and examples of a truly pure bitter we may find in the camomile flowers, the quassia, the gentian, and the columba. These, it is said, are tonic: we can scarcely think so. They are antiseptic, and most probably antacid; and from these qualities they correct the morbid state of the fluids in the stomach, thus giving strength by destroying the causes of weakness. The bile of animals appears to be a pure bitter; yet it is probably not so, since it occasions in the stomach sickness and faintness.
Dr. Cullen seems to suspect that bitters are narcotic; but his chief argument arises from their effects in gout, when, in the form of the duke of Portland's powder, they have been long continued. Various collateral circumstances have, however, convinced us that bitters should not be long continued without some intermission.
Bitters have been used as resolvents; a term not strictly defined, but intended to convey the idea of then-resolving obstructions of the liver or other viscera. When joined with fixed alkalis or neutral salts, they seem to have this effect; and, in this union, they are also febrifuge. They formed the mild febrifuge of Boerhaave, who, with little chemical accuracy, styled them saponaceous. In this form, at least, pure bitters are not injurious to the robust or inflammatory habits; and we suspect that without the union of the salts they would not be hurtful in such constitutions; yet they are seldom, if ever, indicated in persons of this description, and the disquisition would tend to no useful purpose. Bitters, we have said, are stomachic; they are also slightly laxative; but we have never found them, as some authors have alleged, diaphoretic.
There is another class of bitters unconnected with those above mentioned; viz. the narcotic. Of this kind we have examples in the hop, the cocculus Indi-cus, the lactuca virosa, opium, perhaps the bitter of the myrrh) and of the Iceland liverwort. These are never employed, except in very small doses, for the purposes before mentioned. They will be more fully considered under their proper heads. We mention them in this place merely to connect the subjects, and to suggest a suspicion that these two kinds are very nearly related; to enforce also a due attention to the supposed narcotic power of common bitters. With this perhaps their anthelmintic power may be connected; but though the greater number of anthelmintics are bitter, yet it is in a very slight degree, if at all, a property of bitters in general. An additional proof of the connexion of the narcotic with other bitters, is their febrifuge power.
The faba St. Ignatii, a bitter of the narcotic class, is highly celebrated for the cure of intermittents; and a considerable Febrifuge power seems to reside in the greater number.
Bitters yield their virtues both to watery and spirituous menstrua: they yield very little of their taste by distillation, either to water or spirit; nay, the bitterness is so tenaciously detained, as to be improved in many extracts. Cold water extracts the pure bitter without any mixture of unpleasant roughness. Even the cold infusion of the carduus benedictus is pleasant.