tilled oils added to water for counterfeiting the vegetable water can never equal it, artificial chemistry falling short of the natural. 46. The less violence is used to nature the better its produce. The juice of olives or grapes issuing by the lightest pressure is best. Resins that drop from the branches spontaneously, or ooze upon the slightest incision, are the finest and most fragrant. And infusions are observed to act more strongly than decoctions of plants, the more subtile and volatile salts and spirits, which might be lost or corrupted by the latter, being obtained in their natural state by the former. It is also observed that the finest, purest, and most volatile part, is that which first ascends in distillation. And, indeed, it should seem the lightest and most active particles required least force to disengage them from the subject. 47. The salts, therefore, and more active spirits of the tar, are got by infusion in cold water: but the resinous part is not to be dissolved thereby.* Hence the prejudice which some perhaps may entertain against tar water as a medicine, the use whereof might inflame the blood by its sulphur and resin, appears to be not well grounded; it being indeed impregnated with a fine. acid spirit, balsamic, cooling, diuretic, and possessed of many other virtues.† Spirits are supposed to consist of salts and phlegm, probably too somewhat of a fine oily nature, differing from oil in that it mixeth with water, and agreeing with oil in that it runneth in rivulets by distillation. Thus much is allowed, that the water, earth, and fixed salt, are the same in all plants; that, therefore, which differenceth a plant or makes it what it is, the native spark or form, in the language of the chemists or schools, is none of those things, nor yet the finest oil, which seemeth only its receptacle or vehicle. It is observed by chemists, that all sorts of balsamic + Sect. 42. 44. VOL. III. * Sect. 7. U wood afford an acid spirit, which is the volatile oily salt of the vegetable: herein are chiefly contained their medicinal virtues, and by the trials I have made, it appears, that the acid spirit in tar water possesseth the virtues, in an eminent degree, of that of guaiacum, and other medicinal woods. 48. Qualities in a degree too strong for human nature to subdue, and assimilate to itself, must hurt the constitution. All acids, therefore, may not be useful or innocent. But this seemeth an acid so thoroughly concocted, so gentle, bland, and temperate, and withal a spirit so fine and volatile, as readily to enter the smallest vessels, and be assimilated with the utmost ease. 49. If any one were minded to dissolve some of the resin, together with the salt or spirit, he need only mix some spirit of wine with the water. But such an entire solution of resins and gums, as to qualify them for entering and pervading the animal system, like the fine acid spirit that first flies off from the subject, is perhaps impossible to obtain. It is an apothegm of the chemists, derived from Helmont, that whoever can make myrrh soluble by the human body, has the secret of prolonging his days: and Boerhaave owns that there seems to be truth in this, from its resisting putrefaction. Now this quality is as remarkable in tar, with which the ancients embalmed and preserved dead bodies. And though Boerhaave himself, and other chemists before him, have given methods for making solutions of myrrh, yet it is by means of alcohol which extracts only the inflammable parts. And it doth not seem that any solution of myrrh is impregnated with its salt or acid spirit. It may not, therefore, seem strange if this water should be found more beneficial for procuring health and long life, than any solution of myrrh whatsoever. 50. Certainly divers resins and gums may have virtues, and yet not be able for their grossness to pass the lacteals and other finer vessels, nor yet, perhaps, readily impart those virtues to a menstruum, that may with safety and speed convey them throughout the human body. Upon all which accounts, I believe tar water will be found to have singular advantages. It is observed that acid spirits prove the stronger, by how much the greater degree of heat is required to raise them. And indeed there seemeth to be no acid more gentle than this, obtained by the simple affusion of cold water; which carries off from the subject the most light and subtile parts, and, if one may so speak, the very flower of the specific qualities. And here it is to be noted, that the volatile salt and spirit of vegetables do, by gently stimulating the solids, attenuate the fluids contained in them, and promote secretions, and that they are penetrating and active, contrary to the general nature of other acids. 51. It is a great maxim for health, that the juices of the body be kept fluid in a due proportion. Therefore the acid volatile spirit in tar water, at once atte nuating and cooling in a moderate degree, must greatly conduce to health, as a mild salutary deobstruent, quickening the circulation of the fluids without wounding the solids, thereby gently removing or preventing those `obstructions which are the great and general cause of most chronical diseases; in this manner answering to the antihysterics, asafoetida, galbanum, myrrh, amber, and in general, to all the resins and gums of trees or shrubs useful in nervous cases. Therefore 52. Warm water is itself a deobstruent. the infusion of tar drunk warm is easier insinuated into all the nice capillary vessels, and acts not only by virtue of the balsam but also by that of the vehicle. Its taste, its diuretic quality, its being so great a cordial, shew the activity of this medicine. And at the same time that it quickens the sluggish blood of the hysterical, its balsamic oily nature abates the too rapid motion of the sharp thin blood in those who are hectic. There is a lentor and smoothness in the blood for healthy strong people, on the contrary, there is often an acrimony and solution in that of weakly morbid persons. The fine particles of tar are not only warm and active, they are also balsamic and emollient, softening and enriching the sharp and vapid blood, and healing the erosions occasioned thereby in the blood vessels and glands. 53. Tar water possesseth the stomachic and cardiac qualities of elixir proprietatis, Stoughton's drops, and many such tinctures and extracts, with this difference, that it worketh its effect more safely, as it hath nothing of that spirit of wine, which, however mixed and disguised, may yet be well accounted a poison in some degree. 54. Such medicines are supposed to be diaphoretic, which, being of an active and subtile nature, pass through the whole system, and work their effect in the finest capillaries and perspiratory ducts, which they gently cleanse and open. Tar water is extremely well fitted to work by such an insensible diaphoresis, by the fineness and activity of its acid volatile spirit. And surely those parts ought to be very fine, which can scour the perspiratory ducts, under the scarf skin or cuticle, if it be true, that one grain of sand would cover the mouths of more than a hundred thousand. 55. Another way wherein tar water operates, is by urine, than which perhaps none is more safe and effectual, for cleansing the blood and carrying off its salts. But it seems to produce its principal effect as an alterative, sure and easy, much safer than those vehement, purgative, emetic, and salivating medicines, which do violence to nature. 56. An obstruction of some vessels causeth the blood to move more swiftly in other vessels which are not obstructed. Hence manifold disorders. A liquor that dilutes and attenuates resolves the concretions which obstruct. Tar water is such a liquor. It may be said, indeed, of common water, that it attenuates, also of mercurial preparations that they attenuate. But it should be considered, that mere water only distends the vessels and thereby weakens their tone; and that mer cury by its great momentum may justly be suspected of hurting the fine capillaries, which two deobstruents therefore might easily overact their parts, and (by lessening the force of the elastic vessels) remotely produce those concretions they are intended to remove. 57. Weak and rigid fibres are looked on by the most able physicians, as sources of two different classes of distempers: a sluggish motion of the liquids occasions weak fibres therefore tar water is good to strengthen them as it gently accelerates their contents. On the other hand, being an unctuous bland fluid, it moistens and softens the dry and stiff fibres: and so proves a remedy for both extremes. 58. Common soaps are compositions of lixivial salt and oil. The corrosive acrimony of the saline particles, being softened by the mixture of an unctuous substance, they insinuate themselves into the small ducts with less difficulty and danger. The combination of these different substances makes up a very subtile and active medicine, fitted for mixing with all humours, and resolving all obstructions. Soap therefore is justly. esteemed a most efficacious medicine in many distempers. Alcaline soap is allowed to be cleansing, attenuating, opening, resolving, sweetening; it is pectoral, vulnerary, diuretic, and hath other good qualities which are also to be found in tar water. It is granted, that oil and acid salts combined together exist in vegetables, and that consequently there are acid soaps as well as alcaline. And the saponaceous nature of the acid vegetable spirits, is what renders them so diuretic, sudorific, penetrating, abstersive, and resolving. Such, for instance, is the acid spirit of guaicum. And all these same |