From Antispasmodica 893 against, and a convulsion). This class of medicines must be ranked among the more irregular and anomalous groups, as the individuals are adapted to a set of symptoms arising from a variety of causes, and not to a particular end or object. The causes of spasm differ essentially, and the remedies must equally differ. Spasm is obviously irregular action; and, from what we have already hinted, irregular action is commonly the effect of weakness. See Anodynes. In this view antispasmodics must be tonics and stimulants. This, however, though an obvious, is a partial, result of the premises. When action is irregular, we may equally restore the equilibrium by stimulants and by sedatives; more often by the powerful effect of sedatives, which, by stopping all action, enable us to commence it more regularly. Thus in ileus, where strong spasm, and in consequence inverted motion, take place, we succeed better by stopping all muscular exertion, and again commencing the stimulus from above downwards, than by forcing the peristaltic motion in an opposite direction to that which has morbidly taken place. If, then, we were to fix on any general determinate action of antispasmodics, we would say that they were sedatives. Experience, however, corrects such hasty theoretical conclusions; and we shall find that they are sometimes stimulant, more frequently tonic, but most often sedative. Yet there is a class highly useful, referring to neither, the fetids, which we need not enlarge on at this moment, but shall treat of them in turn, under the appellation of anomalous.

The stimulant antispasmodics are not numerous. The chief are electricity and Galvanism. It is an unavoidable inconvenience in a dictionary, that we must anticipate what is afterwards to be fully explained, and the only remedy is, to give shortly the result of reasoning which is at a future period to be more carefully pursued. We shall find that the electrical fluid, and the Galvanic, (if not the same with that which gives activity to the nerves, certainly nearly allied to it,) excite the powers of life by their passage through the nerves. These, then, are stimulant antispasmodics; for they correct the irregular action of muscular fibres with considerable success. Volatile alkali acts, in many instances, very powerfully as an antispasmodic. AEther and ardent spirits are more equivocal; yet, as their action is immediate, we would refer them to the same head. Some other remedies are equally doubtful: we allude to quicksilver and iron. A very extensive view of the action of metals inclines us to consider the whole class as tonics; yet mercury certainly keeps up a steady increased action of the sanguiferous system, and iron, though less pointedly, is of a similar nature. We shall have occasion to explain all the powers of these metals on this principle; and, therefore, must arrange them in this order of antispasmodics.

The tonic antispasmodics are very numerous. Of this kind are the whole metallic tribe with the exceptions just mentioned, viz. arsenic, zinc, copper, and silver. Bark, of course, belongs to this order; and the viscus quercinus, the balsamum Peruvianuin, and cold bathing, will not be refused a place in the same arrangement. The sedatives are also numerous and powerful. Bleeding ranks the highest, and opium follows. No other remedies can claim an equal credit; but warm bathing, fear, and other depressing passions, camphor, the flores cardamines, and, perhaps, hydrogenous gas, have no inconsiderable claims to our attention in the same way. Blisters, as explained under the article of anodynes, are sedative, by lessening the irritation of the sanguiferous system.

The anomalous antispasmodics include the fetids. These, from their effects, we suspect to be sedatives. When breathed, the want of elasticity in carbonic acid and hydrogenous airs gives the sensation of suffocation; and many of these show, in other instances, sedative effects, particularly the asafoetida; the sweet oil of wine, the most active part of Hoffman's anodyne and Tickell's aether; the fetid herbs (including the rue, savine, atri-plcx olida, and aristolochia), petroleum; ambergrise; the fumes of burnt feathers; musk, and civet.

Since we have considered blisters as taking off internal irritation, we might also, in a more general view, consider bleeding as a cause of derivation from a part unusually loaded, and perhaps irritated. Yet we chose to consider it separately, since we would connect this with a very different class of remedies, viz. those which act by arresting the attention, and, of course, breaking the habit. Spasmodic diseases soon become habitual; and when the cause is removed, the paroxysms recur from habit only. Bleeding, either from association or the terror of the operation, acts in this way; and Dr. Whytt has remarked, that a person, usually relieved by bleeding, has experienced the same relief on puncturing the vein. Keeping the attention alive has had a similar power; and it is remarked, that during a siege a town has been peculiarly free from nervous complaints. Sudden terror has been equally effectual; and we thus account for the effects of numerous superstitious remedies formerly recommended.

In another view, emollients and demulcents are antispasmodic; for when the more sensible mucous membranes are inflamed, and the more fluid mucus rapidly carried off, they are morbidly irritable; and from the common stimuli, irregular action is often excited. Causes of this kind sometimes produce spasmodic colics, and what are styled nervous coughs.

In the choice of these we employ the sedatives and fetids to shorten the fit; the stimulants and tonics to prevent returns. The stimulants, when employed in this way, are exhibited in more constant and less active forms, and then, probably, approach the nature of tonics.