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We ftrall now defcend to the-conflder- 
ation of the caufes, which independent of*' 
natural ftimuli have an influence upon the 
fpontaneous motions; but this fubjedt is 
only meant to be touched upon curforily. 
Thefe caufes are, 
i ft. The animal fluids themfelves, which 
may have acquired any difeafed qualities, 
either at the inftant of fecretion, or after, 
by the admixture of other fluids, or by 
ftagnation. 
The bile, for inftance, the urine, and 
the lemen, under the circumftances juft 
mentioned, occalion difagreeable accidents, 
which are not always unattended with 
danger. 
2d, Extraneous matters, either intro¬ 
duced or formed within the body. 
Thus, poifons taken into the ftomach 
occafion diftrefling vomitings, augment 
the adtion of the inteftines, and invert 
their natural motion. Air, gaffes, and 
other 
