MEDICINES. 387 



then well rubbing in the ointment, for at least ten minutos — and after\va»rdg 

 and what is of tlie greatest consequence of all, plastering a little more of 

 the ointment lightly over the part, and leaving it. As soon as the vesicae." 

 have perfectly risen, which will be in twenty. or twenty-four hours, th<^ 

 torture of the animal may be somewhat relieved by the application of oliva 

 or neat's-foot oil, or any emolient ointment. 



When too extensive a blister has been employed, or, from the intensity 

 of the original inflammation, the blister has not risen, (for no two intense 

 inflammations can exist in neiglibouring parts at the same time,) strangury, 

 or great difficulty in passing urine, or even suppression of it, has occurred. 

 The careful washing off of the blister, and the administration of plenty of 

 warm water, with opium, and bleedinsr, if the symptoms run high, will 

 generally remove this unpleasant eiFoct. 



An infusion of two ounces of the flies in a pint of oil of turpentine, for 

 several days, is occasionally used as a liquid blister ; and when sufficiently 

 lowered with common oil, it is called a sweating oil, for it maintains a cer- 

 tain degree of irritation and inflammation on the skin, but not suthcient to 

 blister, and thus gradually abates or removes some old or deep inflamma- 

 tion, or cause of lameness. 



Cantharides have lately been recommended to be given internally, in 

 doses, daily, or twice in the day, of five grains, and increasing the dose to 

 fifteen grains, for the cure of glanders. The experiments are yet too few 

 and indecisive to admit of any satisfactory conclusion. In these doses the 

 fiy has not been injurious, and the experiments are considered as well 

 worth prosecuting. 



Carraways. — These and ginger ai'e retained as the only cordials requi- 

 site for the horse. 



Castor Oil is here introduced again to warn the horse-owner and the 

 practitioner against the too frequent use of it. If it is a purgative in the 

 horse, it must be given in the enormous and expensive doses of a pound or 

 a pound and a half; even then, it is uncertain in its efiect — often gripes, 

 and is unsafe and dangerous. 



Catechu, Japan earth, yet no earth, but extracted from the wood of one 

 of the acacia trees, is a very useful astringent. It is given in super-pur.- 

 gation, in doses of one or two drachms, with one or one and a half drachm 

 of opium, as a yet more powerful astringent ; four drachms of chalk, to 

 neutralize any acid in the stomach or bowels, and two drachms of pow- 

 dered gum being also added, to sheath the over-irritated mucous coat of 

 the intestines. It is not often adulterated in our country, but grossly so 

 abroad — fine sand and aluminous earth being mixed with the extract. It 

 should not be given with any alkali, yet the prescription just recommended 

 contains chalk. But although the chalk, being an alkali, weakens the 

 astringencyof the catechu, it probably neutralizes some acid in the stomach 

 or bowels, which would have diminished the power of the catechu to a 

 greater degree. It must not be given in conjunction with any metallic 

 salt, for the tannin or gallic acid, on which its power chiefly or entirely 

 depends, has an affinity for all metals, and will unite with them, and form 

 a gallate of them, possessing little astringent energy. Common ink is the 

 union of this tannin principle with iron. 



A tincture of catechu is sometimes made by macerating three ounces 

 of the powder in a quart of spirit for a fortnight. It is a very excellent 

 application for healing wounds ; and, with the aloes, constitutes all that we 

 want of a balsamic nature for the purpose of hastening the curative pro- 

 cess, and establishing soundness. 



Caustics. — These are sometimes necessary to destroy fungous excres- 



