MEDICINE. 513 



but it is a powerful antispasmodic, sedative, and astringent. As an antispas- 

 modic, it enters into the cholic drink, and it is the sheet-anchor of the veterinarian 

 in the treatment of tetanus or locked jaw. As a sedative, it relaxes that uni- 

 versal spasm of the muscular system which is the characteristic of tetanus ; 

 and, perhaps, it is only as a sedative that it has such admirable effect as an 

 astringent, for when the irritation around the mouths 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 irritability 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 occasioned. It is 

 given in doses of one or two drachms, in the form of ball. Other medicines are 

 usually combined with it, according to the circumstances of the case. 



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

 head, it may constitute the basis of an anodyne poultice; but it must not be given 

 in union with any alkali, 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 toughness and pli- 

 ancy, its fawn or brown colour, and its weight, for it is the heaviest of all the 

 vegetable extracts, except gum arabic ; yet its weight is often fraudulently in- 

 creased by stones and bits of lead dexterously concealed in it. The English 

 opium is almost as good as the Turkish, and frequently sold for it ; but is dis- 

 tinguishable by its blackness and softness. 



PALM OIL, when genuine, is the very best substance that can be used for 

 making masses and balls. It has a pleasant smell, and it never becomes rancid. 



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 sandcrack 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 cooling 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 sur- 

 rounding air. The Bitartrate of Potash (Cream of Tartar) is a mild diuretic, 

 and, combined with .^Ethiop's mineral, is used as an alterative in obstinate 

 mange or grease. The objection, however, to its use in such an animal as the 

 horse, is the little power which it seems to exercise. 



