> tie, Tear 
ee ee ee eee ee Se a i, Sha 
ee er 
~~ 
ee os a 
SECT. XII. PHYSIOLOGY. 109 
I shall elucidate the irritability of the lymphatics 
in the more common disease of white swelling. 
ceLviu. It will scarcely be denied, I apprehend, 
that white swelling of the knee-joint proceeds 
from defective lymphatic absorption; or, in other 
words, morbid contraction of the lymphatic tubes. 
I shall endeavour to place this conclusion in a 
simple and clear light, by a very easy experiment. 
-ec~ix. When a lunar caustic eschar is applied 
to a white swelling of the knee-joint, the expan- 
sibility of the absorbents is renewed ; but although 
there be generally no inflammation except at the 
edge of the slough, yet the extreme arteries of 
the joint are also.a little expanded the first three 
or four days. But by the twelfth day of the 
eschar, the swelling has subsided sometimes a full 
inch by absorption alone; for lunar caustic causes 
searcely any discharge of pus. The sudden ab- 
straction of the effused fluid, in a diseased joint 
thus treated, cannot be supposed to result from 
the lymphatics alone; the veins, doubtless, con- 
tribute material assistance: but the principle of 
venal and lymphatic absorption is the same. 
ccux. Cantharides have also a very powerful 
effect upon the absorbents ; a blister applied to the 
scrotum, in hydrocele, throws its lymphatics into 
a state of great activity, and the effused fluid is 
quickly taken up by their expanded tubes; but 
when the artificial excitement is at an end, the 
