The peculiar character of castor oil as a cathartic suggests its therapeutic application. it may be used in all cases where the indication is simply to evacuate the contents of the bowels, and to effect this object as speedily, and with as little irritation of the mucous membrane as pos-ble. From its demulcent nature, it is peculiarly adapted to those cases in which the mucous membrane is already irritated or inflamed.

In cases of colic, dependent on feculent accumulation, acrid secretions, or indigestible substances in the bowels, it generally answers an excellent purpose; not unfrequently, in conjunction with aromatics or opiates, affording complete relief.

In all cases of occasional constipation, and feculent accumulation or obstruction, castor oil may be tried. in mild cases it will usually answer the desired purpose, as in the costiveness of convalescence, that of pregnancy and the puerperal state, and, generally speaking, in that of young children; but in the more obstinate cases, requiring more vigorous contraction of the bowel, it will often be necessary to have recourse to some more energetic cathartic. When there is a great mass of impacted feces, castor oil is generally inadequate to its removal. Here the hydragogue cathartics, especially the neutral salts, are more efficacious by promoting watery extravasation, and thus softening and breaking up the mass. Nor is castor oil generally well adapted to habitual constipation; not from any deficiency of power, but from the circumstance that few persons can take it very frequently, without acquiring such a disgust for it, that it can no longer be borne on the stomach. There are, however, individuals who acquire a sort of relish for it, or at least can take it without the least aversion; and, in such persons, I have found it to answer well as a habitual laxative in small doses.

Diarrhoea of irritation is often completely relieved by a dose of castor oil with laudanum; the latter calming the irritation, while the former carries off the offending cause; and, in mucous enteritis, the same combination is very useful, at or near the commencement of the attack. So also in irritated piles, prolapsus ani, stricture and organic affections of the rectum, it is among the best cathartics for occasional use; though rarely supportable by the stomach when its very frequent repetition is required.

Mild cases of dysentery, treated at the very commencement with a full dose of castor oil, are sometimes cut short by it, and generally benefited; and, in severe cases, the oil may be given with advantage, either associated with calomel, or in a few hours after a dose of the mercurial. in the course, moreover, of the disease, an occasional dose of the oil often proves useful; and, in that irritated state of the bowels, in the advanced stage, in which, with little violence of inflammation, the patient is troubled with a constant desire to go to stool, with small and ineffectual evacuations, the oleaginous mixture with a little laudanum, given in doses of half a fluidounce every hour or two, often answers an excellent purpose.

No cathartic is so appropriate in typhoid or enteric fever, when, as not unfrequently happens, there is an indication for a gentle evacuation of the bowels. One fluidrachm will often operate kindly, and without the least annoyance to the patient; but, if it should not be found to answer, the dose may be cautiously increased.

To the summer complaint of children the oil is well adapted, when tolerated by the stomach; and here, as in the advanced stages of dysentery, the oleaginous mixture with a little laudanum will often be found to answer well, when the pure oil might be rejected.

In peritoneal inflammation, also, when cathartics are indicated in order to remove feculent matter from the bowels, castor oil is usually the most appropriate.

In irritated states of the bladder and genital apparatus, it is among the best cathartics; but, when the affection amounts to inflammation with fever, the purgative salts are usually to be preferred.

Castor oil has been recommended for tapeworm, though of doubtful efficacy. It is not impossible, however, that, if taken very largely, it may injure the worm by involving it so as to prevent the access of air, and, having thus weakened, may expel it by its purgative action. I have been informed of a case in which the long and free use of olive oil, followed by a dose of castor oil, resulted in the discharge of a portion of worm thirty feet long. (See my Treatise on the Practice of Medicine 5th ed., i. 693.)

From its mildness and efficiency, castor oil is admirably adapted to infantile cases, of whatever kind, when simple evacuation of the bowels is indicated. It seems to be even less irritant to the stomach and bowels in children than in adults, and generally requires to be administered in a much larger relative dose. It is given in most of their complaints; magnesia only being preferred to it when there is excess of acid.

Administration

The full dose for an adult is a fluidounce, though half the quantity or even less will often operate. For infants it may vary from one to four fluidrachms. Seldom less than a fluidrachm is given to a child more than three or four months old.

To infants it may often be given directly from the spoon. For older children and adults, the common method of administration is to introduce a little mint-water, or other aromatic water or infusion, into a wineglass, and, having moistened the inner surface of the glass, to pour in the oil, vol. ii.-33 and cover it with more of the vehicle. The patient then takes it down at one or two swallows, and avoids the unpleasant and durable taste arising from its adhesion to the lips, tongue, etc. if the oil is previously warmed, so as to render it thinner, it will be swallowed with still greater facility. Another method is to take it in a small cup of hot coffee, with cream and sugar. it may also be administered in a kind of emulsion with hot milk, or in the froth of porter when this is not contraindicated. These directions are not without importance; as the method of exhibition often determines whether the oil will be retained on the stomach or rejected. it has recently been ascertained that the volatile oil of bitter almonds completely neutralizes the repulsive odour and taste of the oil, and substitutes an agreeable flavour, which renders its administration perfectly easy. Three drops of the volatile oil are sufficient to produce this effect with about three ounces of castor oil. (M. Jaennel, Journ. de Pharm. et de Chim., 3e sÚr., xxxviii. 361.)

An oleaginous emulsion may be made by taking a fluidounce of the oil, two drachms of powdered gum arabic, a drachm and a half of loaf sugar, and three fluidounces of mint-water; dissolving the gum and sugar in a little of the water so as to make a mucilage of about the same consistence with the oil, then rubbing the mucilage with the oil, and finally adding the remainder of the aromatic water. Any other aromatic liquid may be substituted for the mint-water, as diluted cinnamon-water, strong fennel-seed tea, etc.; and the yolk of an egg may be substituted for the gum arabic. A tablespoonful of the mixture, containing a fluidrachm of the oil, may be given every hour, two, or three hours till it operates; or a larger quantity may be taken at once if required. in dysenteric cases, and the bowel complaints of children, it will often be found useful to add a little laudanum to each dose.

There are other fixed oils which have a laxative effect, and have sometimes been used for the purpose.

Olive Oil (Oleum Olivae) has occasionally been substituted for castor oil, and has a somewhat similar effect, though much feebler. it must be given in double the quantity.

Linseed Oil (Oleum Lini) has similar properties; but is so disagreeable that it is seldom used.

Melted Butter has sometimes been used with advantage, as a laxative, in the advanced stages of dysentery, and in the same disease in a chronic state, in the dose of a tablespoonful every two hours. it is prepared by introducing the butter into a deep tin-cup nearly filled with hot water, stirring for a time, and then allowing the mixture to stand. The butter having been melted by the heat of the water, by which also any salt that may have been mixed with it is dissolved, rises to the surface, and may be skimmed off as wanted.

All the oils just mentioned, including castor oil, are often administered by enema, in quantities varying, according as they are given with other substances or alone, from one to four fluidounces. Thrown up in an unmixed state, they often prove serviceable, in cases of threadworm infesting the rectum, by suffocating the little animal through the exclusion of air.

Castor oil is sometimes applied externally to the breasts of nursing women, to increase the secretion of milk. I can say nothing, from my own knowledge, in relation to its efficiency.