TREATMENT OF DISEASES OF THE HORSE. 493 



there is not a more valuable drug on our list. It does not often act as 

 a narcotic except in considerable doses ; but it is a powerful antispas- 

 modic, sedative, and astringent. As an antispasmodic, it enters into tbe 

 coHc drink, and it is tbe sbeet-ancbor of the veterinarian in the treatment 

 of tetanus or locked-jaw. As a sedative, it relaxes that universal spasm 

 of the muscular system wliicli is the characteristic of tetanus ; and, perhaps, 

 it is only as a sedative that it has such admii^able effect as an astringent, 

 for when the irritation around the mouth of the vessels of the intestines 

 and kidneys is allayed by the opium, the undue purging and profuse 

 staling will necessarily be arrested. 



Opium should, however, be given with caution. It is its secondary 

 effect that is sedative, and, if given in cases of fever, its primary effect in 

 increasing the excitation of the frame may be very considerable and highly 

 injurious. In the early and acute stage of fever, it would be bad practice 

 to give it in the smallest quantity ; but when the fever has passed, or is 

 passing, there is nothing which so rapidly subdues the irritabihty that 

 accompanies extreme weakness. It becomes an excellent tonic, because it 

 is a sedative. 



If the blue or green vitriol, or cantharides, have been pushed too far, 

 opium, sooner than any other drug, quiets the disorder they have oc- 

 casioned. It is given in doses of one or two drachms, in the form of ball. 

 Other medicines are easily combined with it, according to the circum- 

 stances of the case. 



Externally, it is useful in ophthalmia. In the form of decoction of the 

 poppyhead, it may constitute the basis of an anodyne poultice ; but it 

 must not be given in union with any alkah, with the exception of chalk, 

 in over-purging ; nor with the superacetate of lead, by which its powers 

 are materially impaired ; nor with sulphate of zinc, or copper, or iron. 



From its high price, it is much adulterated, and it is not always met 

 with in a state of purity. The best tests are its smell, its taste, its tough- 

 ness and pliancy, its fawn or brown colour, and its weight, for it is the 

 heaviest of all the vegetable extracts, except gum arable ; yet its weight 

 is often fraudulently increased by stones and bits of lead dexterously 

 concealed in it. 



Pitch is used to give adhesiveness and firmness to charges and plasters. 

 The common pitch is quite as good as the more expensive Burgundy pitch. 

 The best plaster for sand-crack consists of one pound of pitch and an ounce 

 of yellow bees- wax melted together. 



Physic. — The cases which require physic, the composition of the most 

 effectual and safest physic ball, and the mode of treatment under physic, 

 have been already described. 



Potash. — Two compounds of potash are used in veterinary practice. 

 The Nitrate of Potash (Nitre) is a valuable cooHng medicine and a mild 

 diuretic, and, therefore, it should enter into the composition of every fever- 

 ball. Its dose is from two to four drachms. Grooms often dissolve it in 

 the water. There are two objections to this : either the horse is nauseated, 

 and will not drink so much water as he ought ; or the salt taste of the 

 water causes considerable thirst, and disinclination to solid food. Nitre, 

 while dissolving, materially lowers the temperature of water, and furnishes 

 a very cold and useful lotion for sprain of the back sinews, and other local 

 inflammations. The lotion should be used as soon as the salt is dissolved, 

 for it quickly becomes as warm as the surrounding air. The Bitartrate of 

 Potash (Cream of Tartar) is a mild diuretic, and, combined with -^thiop's 

 mineral, is used as an alterative in obstinate mange or grease. The objec- 

 tion, however, to its use in such an animal as the horse is the little power 

 which it seems to exercise. 



