188 BOVINE PATHOLOGY. 



general treatment of the animals, lie directs his investi- 

 gations to the nature of the pasturage. Careful inspec- 

 tion of all parts of the field or fields is necessary, for the 

 growth of some plants is confined sometimes to very 

 small spots, and one individual plant may destroy a herd. 

 The general and special nature of the flora must be ex- 

 amined, all known plants being duly noted, all unknown 

 plants suspected and investigated. The hedges, trees, and 

 substances around the field, which are accessible to the 

 occupant, must be observed, and the general character of 

 the ground, as nature of soil, elevation, irregularities ; also 

 the kinds of manure which have been used to it must not 

 escape notice. 



Poisons, however, gain entry into the system also 

 through the respiratory mucous memhranej as in carbonic 

 acid poisoning and overdose of chloroform, or through the 

 sMiiy as where poisonous dressings have been applied 

 for skin disease, especially when surface abrasions are 

 present. Cases are sometimes seen in which agents are 

 absorbed from wounds, as arsenic in cases of fistula ; and 

 the subcutaneous areolar tissue may be the seat of intro- 

 duction of the poison, as in overdose of agents by the 

 subcutaneous-injection method of administration. How- 

 ever they gain entry into the system these agents either 

 give rise to great local disorder or undergo absorption, 

 and thus produce their poisonous effect as medicinal agents 

 act. They are in the latter case sooner or later removed 

 by the excretory organs, which is a fact of great clinical 

 value, for thus, by an examination of the faeces or the 

 urine, a diagnosis may be confirmed or otherwise, and 

 sometimes guilt be brought home to a culprit who would 

 otherwise escape unless his victim died. Death is pro- 

 duced in the usual ways ; by the action of poisons, either 

 directly or indirectly, cessation of the heart's action is 

 brought about. It must be remarked that in cases of 

 proved or suspected poisoning the greatest care should be 

 exercised in making a plain record of the facts, as, 

 perhaps more frequently than any others, these prove the 

 cause of litigation. 



