462 MEDICINES. 



lsti« 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 wil' 

 necessarily be arrested. 



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

 ndary 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 decoc- 

 tion 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 superace- 

 tate 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 pliancy, its fawn or brown color, 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. The English 

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

 but is distinguishable 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. 



Pepper, — see Capsici Bacc^. 



Pitch, — is used to give adhesiveness and firmness to charges 

 ind piasters. The common pitch is quite as good as the more 

 ^expensive Burgundy pitch. The best plaster for sand-crack con- 

 sists of one pound oi" pitch and an ounce of yellow beeswax melted 

 together. 



Phvsic. — The cases which require physic, the composition of 

 ihe most effectual and safest physic-ball, and the mode of treat- 

 ment under physic, have been already described. 



Potash. — Two compounds of potash are used in veterinary 



