BIT they might have been injurious to the tender organs of digestion of the embryon plant. In some seeds, however, he adds, there is a bitter quality, which refuses to mix with the oleaginous part ; as the oil ex- pressed from bitter almonds is as tasteless as that from the sweet kind. Vegetable bitters possess the combined properties of astringents and aromatics. Hence they are frequently employed in weakness of the stomach and intestines ; in cold habits, where the bile and humours require to be attenuated or diluted ; and for promoting na- tural evacuations, particularly those by the pores and the urinary canal. They aie also of service in many cases of indigestion, loss of appe- tite, flatulency, &c. when these complaints proceed from muscular weakness, or a phlegmatic and inert state of the fluids. But, in constitutions where the fibres are tense and rigid, or an immoderate heat and inflammation prevail, the continued use of bitters, especially in the gout, would sensibly in- crease the disorder, and frequently determine it to the kidneys. Thus the secretion of urine might be greatly checked, to the injury of the patient, and at length either dropsy or consumption would be the natural consequence. It is not easy to conceive, in what manner bitters taken by the stomach operate on the human system ; though they are generally considered as powerful tonics. So much is certain, that they do not act as stimulants ; because neither the frequency of the pulse, nor the force of the circulation, is increased by their use. Nor can it be main- tained, that their operation is similar to that of astringents ; so that bit- III. VOX.. I. BIT [z 7 V ters are to be considered purely as tonics, which strengthen, or im- part new energy to the muscular fibres of the stomach ; an effect which is by sympathy communi- cated to other parts of the body. Bitter substances .are often used as vermifuges, though seldom effi- cacious 5 and externally, as anti- septics. In domestic economy, they are, at present, chiefly em- ployed for the destruction of in- sects, &c. ; but it deserves to be remarked, that there is scarcely a litter root growing in this island, which might not be converted to very useful purposes. — See Bread. Bitter Salt. See Epsom Salt. Bitter - Sweet. See Woody Nightshade. BITUMENS, are inflammable mineral bodies, not sulphureous, or only casually impregnated with sulphur. They are of various de- grees of consistence,' and appear, • in the mineral kingdom, to corres- pond with the oils and resins in the vegetable. By their peculiar smell, they are easily distinguished from either purely animal or vegetable productions. When the native rock-oils are mixed with concen- trated mineral acids, they become thick, and at length consistent : in which state they are called Hiu- mens. There is a. thin fluid bitumen called naphtha, which is found on the surface of waters, or oozing from clefts of rocks in the eastern countries, particularly Persia. It has a strong srhell, very different from that ot vegetable or animal oils, is highly inflammable, not so- luble in spirit of wine, and almost as limpid as water, with which it is more averse to unite than any other oil. Next to naphtha, in consistence, is petroleum, or rock- ' T oil:
