64 ANALYTIC SECT. VIIy 
opposing muscles mechanically overcome the 
spasm, the pain is removed. To this opinion it 
may be objected, that tetanus in one. instance 
caused no pain; but a few anomalous cases can 
neither establish nor overthrow general physio- 
logical principles. In the spasm which some- 
times attends hemiplegia, the pain is indeed 
usually inconsiderable, or wears off; but in eases 
of this description, the sensibility is at the same 
time impaired. And most authors agree, that the 
persons most obnoxious to tetanus, are those who 
have very strong, rigid muscles, and are about the 
prime of life. 
cxtvit. The propagation of spasm from onak 
to muscle, in stricture and tetanus, would seem to 
favour the inference, that the pressure of the 
muscles upon the nerves operates like ligatures, 
and that the spasm of one muscle becomes the 
cause of spasm in those adjacent to it. 
cxLvu. I entirely coincide with Areteus, that 
tetanus is a disease of the nerves, but others hold 
different opinions. From worms having been 
often detected in the bowels of persons who had 
died of tetanus, some have considered these ver-: 
min as the cause of the disease. Since anatomists 
have carried their search of disease into the verte- 
bral canal, a more plausible doctrine, founded, 
upon the morbid appearance of the spinal marrow, 
