134 I^AVIN ox THE HORSE. 



affected at first, but becomes quick, small, and irregular; the 

 expression is indicative of the most excruciating pain and 

 agony. Sensibility and perception do not appear to be de- 

 s°royed,or much impaired, for, when he is as immovably fixed 

 as a statue, his pulse quickens at the approach of any thing that 

 would excite fear. These symptoms may continue for a week 

 or ten days; until the powers of life give way under the con- 

 tinued exhaustion of hunger and pain ; and not until in the 

 very embrace of death does any relaxation of the universal 

 spasm take place, and the poor sufi'erer yields the victory to 

 the grim conqueror only after having reached the extreme of 

 vital endurance. 



Causes.— It is well known that all muscular movement 

 is produced by a stimulus imparted by the nerves called 

 nerves of motion. This stimulus is supposed to originate in 

 the brain, and is sent from it along the nerves to the muscles 

 which it is intended to excite to action or cause to contract. 

 This stimulus is sent to all muscles by an effort of the will ; 

 except certain muscles which act independent of the will, as 

 those of the heart, lungs, etc. IS'ow, if the nerves are so dis- 

 eased that the animal loses control of this stimulus, and it con- 

 tinues to flow without restraint to the muscles, a continued and 

 powerful contraction of the muscles will be the result. And 

 this seems to be the case in tetanus. All the muscles of the 

 system, however, do not become tetanic at once. The anmial 

 loses control of them as the nerves leading to them become in- 

 volved in the unhealthy state, whatever it may be. Tetanus 

 is just the opposite of palsy or paralysis, which is an entire 

 cutting off of nervous stimulus, depriving the muscles of 

 motion of power to contract. This is, we think, the immedi- 

 ate cause of the contraction of the muscles. But the question 

 arises, "Whence comes this nervous derangement?" Does it 

 take place as an original disease, or is it symptomatic ? These 

 are questions which have puzzled the deepest investigators, and 

 about which there have been various opinions entertained. 



