TREATMENT. 403 



it is found there, of changing its form, attracting it from its 

 situation and combinations to again enter the circulation, and 

 thereby become subject to ehmination through the ordmary 

 channels. For this purpose experimentation goes to show 

 that the properly regulated exhibition of iodide of potassium 

 has a -wonderful influence in determining and favouring this 

 result. 



When this remedy is adopted, it is advisable both to 

 precede its administration by the magnesian sulphate in full 

 doses, as also, at different times during its use, to act upon the 

 bowels by the same medicine, in combination with the acid 

 mixture already recommended. 



When, however, the animals are so severely affected that 

 the joints are much swollen and the muscles are paralyzed, 

 the results to be obtained by treatment are not worth the 

 expense of carrying it into execution. While, in the manage- 

 ment of any case, either of the acute or chronic plumbism, in 

 addition to whatever medical treatment is being carried out, 

 it is necessary that the animal be removed from the originally 

 operating cause, the reception of the lead into the system. 



« CHAPTER XL 



TETANUS — LOCK-JAW. 



Definition. — Tliis is the term applied to that disease of the 

 nervous system characterized by involuntary, painful, and 

 continued or tonic spasm of more or less extensive groups of 

 voluntary muscles, and probccbly also certain of the involun- 

 tary ; these spasms, during their continuance, being marked 

 by periods of exacerbation and of repose. 



Pathology, a. Nature and Causation. — The exact nature of 

 this diseased condition, of which we are chiefly cognizant by 

 the disturbance of muscular function, and in which, like some 

 others affecting the nervous system, the lesions observable after 

 death are neither very obvious nor uniform, is not yet placed 

 beyond dispute. By many the characteristic phenomena of 

 increased and sustained muscular contraction is explained 



26—2 



