INTRODUCTION. 73 



check the ravages of an epizootic in a herd or to prevent 

 access of a dreaded disorder. 



In such cases isolation must be rigidly enforced, all 

 predisposing and exciting causes must be removed or 

 obviated. The slightest trace of disease, of any kind, in 

 one or more of the animals, must lead to segregation. 

 Measures of disinfection of houses, utensils, and atten- 

 dants, must be carried out with energy ; and to effect 

 this, the manager of the herd must be a thoroughly reli- 

 able man. Under these circumstances we shall probably 

 succeed in our efforts to prevent or limit an invasion. 



Section 3. • 



In the present section we will place before our readers 

 as succinctly as possible the therapeutical actions of 

 such medicinal agents as have been utilised in the 

 treatment of cattle, availing ourselves of modern thera- 

 peutical ideas, of the researches which have recently been 

 occupying observers of the actions of medicines, and of 

 the assistance of the several works on veterinary medicine 

 and pharmacy, which have been presented to the profes- 

 sion. We shall follow in the main the system adopted 

 by Headland in his most admirable ^Action of Medi- 

 cines,^ adapting this to our special requirements. We 

 shall use the tabular form as most economical of space, 

 and shall so arrange matters that we may utilise our 

 system afterwards in our notice of toxicology. 



For ADMINISTRATION to the OX agents are generally prepared 

 in a draught (or '^ Drench''), soluble matters being dissolved 

 in the water, which is usually the principal vehicle, insoluble 

 matters being in a state of powder and suspended. Drenches 

 are preferred for the ox because they can be readily ad- 

 ministered, act sooner than solid masses, and probably al- 

 most always mainly pass into the third and fourth stomachs 

 directly without delay in the rumen, and the chance of 

 rejection during rumination. In practice a bottle with 

 a gradually tapering neck is found to be useful for ad- 



