480 A LIST OF TIIK ]\[EDICIXES USED IX 



iri then delivered witli a slig-lit jerk, aud the hand being withdrawn and 

 the tong-ue 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 the passage of it is not seen going do\vn, a slight tap or blow 

 under the chin will generally cause the liorse to swallow it, or a few gulps 

 of water will convey it into the stomach. Very few balls should be kept 

 ready made, for they may become so hard as to be incapable of passing- 

 down the gullet, or dissolving in the stomach, and the life of the horse 

 may be endangered or lost. This is peculiarly liable to be the case if the 

 ball is too large, or wrapped in thick paper. The balling-probang, which 

 may be obtained of any veterinary instrument maker, aflTords great facility 

 in administering a ball, avoiding that risk of an awkward scratch, or bruise 

 on the back of the fauces which cannot always be avoided. They are 

 now made in a very portable form, and should be found in every large 

 establishment. 



Baek, Peruvian. — There are several varieties of cinchona or Peruvian 

 bark, but the one most commonly employed is the Cinchona Flava or 

 yellow bark, the produce of a tree growing in difierent parts of South 

 America. Administered either in the form of infusion or powder, it 

 possesses very valuable tonic properties, and is especially serviceable in 

 those cases where great debility is present as the result of influenza. Its 

 active properties depend upon a principle named quinine, which is highly 

 valued as a tonic in human medicine, but at the present time is too expen- 

 sive for general use in veterinary practice. 



Basilicon is a valuable digestive ointment, composed of resin, bees' - 

 wax, and olive-oil. If it is needed as a stimulant, a little turpentine and 

 verdigris may be added. 



BsLLADONNiE EXTRACTUM, EXTRACT OF DEADLY ISTlGHTSHADE. The inspis- 

 sated juice of the Atropa Belladonna is principally used as a narcotic and 

 sedative, and indicated where there is undue action of the nervous and vas- 

 cular systems, as in tetanus, pneumonia, and nervous afi'ections generally. 

 Externally, it is beneficially ajoplied to the eye, on which its action is most 

 peculiar and extraordinary, its sole effect being on the iris or curtain of 

 the eye. This curtain, as has been detailed elsewhere, has two sets of 

 muscles, one set to enlarge, the other to close the pupillary opening. The 

 great peculiarity is, that it is only on the muscles that dilate the pupil 

 that this medicine has any power ; and when they are under its in- 

 fluence, the pupil becomes as ftdly distended as in paralysis of the optic 

 nerves. 



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 exhalant vessels of the skin, by means of which, tliis fluid is thrown 

 out. The part or neighbouring parts are somewhat relieved by the dis- 

 charge, but more by the inflammation and pain that are produced, and 

 lessen that previously existing in some contiguous part. On this prin- 

 ciple we account for the decided relief often obtained by blisters in inflam- 

 mation of the lungs, and their efficacy in abating deeply-seated disease, as 

 that of the tendons, ligaments, or joints ; and also the necessity of pre- 

 viously removing, in these latter cases, the superficial inflammation caused 

 by them, in order that one of a difierent kind may be excited, and to which 

 the deeply-seated inflammation of the part will be more likely to yield. 

 The blisters used in horse-practice are composed of preparations of can- 

 tharidesorthebiniodide of mercury, to which some have added a tincture 

 of the croton-nut. 



For some important remarks on the composition, application, and 

 management of the blister, see page 461. 



