2,6 Dr . Young’s Lecture on the Functions 
of redness, and in most cases pain : the heat will also gene- 
rally be increased, on account of the increased quantity of 
blood which will be allowed to pass through the part ; and 
since the hydrostatic pressure of the blood acquires greater 
force, as the artery becomes more distended, it may be so 
weak as to continue to give way, like a ligament which has 
been strained, until supported by the surrounding parts. In 
this state a larger supply of blood will be ready for any pur- 
poses which require it, whether an injury is to be repaired, or 
a new substance formed ; and it is not impossible, that this 
change in the state of the minute vessels may ultimately pro- 
duce some change in the properties of the blood itself. 
The more the capillary arteries are debilitated and dis- 
tended, the greater will be the mean velocity of the circula- 
tion ; but whether or no the velocity will be increased in the 
vessels which are thus distended, must depend on the extent 
of the affected part ; and it may frequently happen that the 
velocity may be much more diminished on account of the dila- 
tation of the space which the blood is to occupy, than increased 
by the diminution of the resistance. And on the other hand, 
the velocity may be often increased, for a similar reason, at 
the place of a partial contraction. Hence we may easily un~ 
derstand some of the experiments which Dr. Wilson has re- 
lated in his valuable treatise on fevers : the application of spirit 
of wine to a part of the membrane of a frog's foot contracted 
the capillary arteries, and at the same time accelerated the 
motion of the blood in them, while in other parts, where in- 
flammation was present, and the vessels were distended, the 
motion of the blood was slower than usual. 
Another species of inflammation may probably be occa- 
