386 



THE HORSE 



liberated, the ball is forced through the pharynx into the oesophagus. Its 

 passage should be watched down the left side of the throat ; and if it is 

 not seen going down, a slight tap or blow under the chin will generally 

 cause the horse to swallow, or a few gulps of water will carry it down. If 

 the "-ullet should be small, or strictured, and the ball should remain in 

 some part of it, the method of removing it has been described in page 162. 

 Blisters are applications to the skin which separate the cuticle in the 

 form of vesicles containing a serous fluid. They excite increased action 

 in the vessels of the skin, by means of which this fluid is thrown out. The 

 part or neighbouring parts are somewhat relieved by this discharge, but 

 more by the inflammation and pain which are produced, and which lessen 

 the inflammation and pain previously existing in some contiguous part. 

 On this principle we account for the decided relief often obtained by 

 blisters in inflammation of the lungs ; their efficacy in abating deeply- 

 seated inflammation, as that of sprain of the tendons, ligaments, or joints ; 

 and the necessity of removing first, in these latter cases, the superficial in- 

 flammation caused by the sprain, that inflammation of a different kind may 

 be excited instead of it, to which the deeply-seated inflammation of the 

 part will be more likely to yield. The blisters used in horse-practice 

 are composed only of cantharides or the oil of turpentine, to which some 

 have added a tincture of the Croton-nut. The method of forming the 

 best blister is mentioned at page 186. 



Bole Armenian is an argillaceous earth combined with iron, and is 

 supposed to possess some astringent property. The propriety of its 

 being best administered in v/ardly is doubtful; for it may remain in the 

 intestinal canal, and become the nut of a stone. On account of its supposed 

 astringency, it is employed externally to give consistence to ointments 

 for o-rease. Even the bole Armenian has not escaped the process of 

 adulteration, and is largely mixed with inferior earths. The fraud may 

 be suspected, but not satisfactorily detected, by the colour of the powder, 

 which should be a bright red. 

 Burgundy Pitch. — See Resin. 

 Calamine. — See Zinc. 

 Calomel. — See Mercury 



Camphor is the produce of one of the laurus species, a native of Japan, 

 and is imitated by passing a stream of chlorine through oil of turpentine. 

 The efficacy of this drug when used internally is very doubtful. The 

 camphor ball is a favourite with the groom, and occasionally administered 

 by the veterinary surgeon, but, seemingly, with no definite object, for it 

 has not been yet determined whether it is to be considered as a sedative, 

 antispasmodic, or stimulant. It is, however, a stimulant, when applied ex- 

 ternally. In the form of camphorated oil, it promotes the absorption of 

 fluids thrown out beneath the skin, the removal of old callus, and the sup- 

 pleing of joints stiff from labour. Combined with oil of turpentine it is 

 more^ffective, but in that combination it occasionally blemishes. 



Cantharides are the basis of the most approved and useful veterinary 

 blisters. The cantharis is a fly, the native of Italy and the south of 

 France, destroyed by sulphur, dried and powdered, and mixed with palm 

 oil and resin, in the proportions directed at page 186. Its action is in- 

 tense, and yet superficial ; it plentifully raises the cuticle, but never injures 

 the true skin, and therefore never blemishes. The application of other 

 acrid substances is occasionally followed by deep-seated ulcerations; but a 

 blister, composed of the Spanish fly alone, while it does its duty, leaves, 

 after a few weeks have passed, scarcely a trace behind. The art of 

 blistering consists in cutting, or rather shaving the hair perfectly close — 



