162 
W. L. WILLIAMS. 
physiological, can only be temporarily maintained, but during 
which period a comparatively slight disturbance of the equi¬ 
librium may bring about results of a grave pathological 
character. 
e Finally the period of sudden exertion causes through the 
arousing of sweat and other secretions a rapid withdrawal of 
water from the blood, while at the same time solid products of 
tissue waste are promptly thrown into its current, the two fac¬ 
tors combined serving to render it so far sub-normal in its rela¬ 
tive amount of water that the resultant density makes it impos¬ 
sible for the blood current to pass normally through the capil¬ 
laries, leading rapidly to blood stasis, extravasation, necrosis' 
of the blood, breaking down of the red blood cells, their resorp¬ 
tion and eventually excretion by the kidneys—haemoglo- 
binuria. 
It has been experimentally shown that a muscle at work re¬ 
quires about 75 per cent, more blood than the same organ at rest, 
and we constantly observe that locomotory muscular contractions 
offer the greatest physiological resistance to the blood current, in¬ 
creasing the number and force of the heart’s beats. We should 
then expect to and do find that the blood stasis occurs in the 
capillaries of the great muscles of locomotion, with engorge¬ 
ment of arteries and capillaries, extravasation of blood into the 
muscular tissue, with tumefaction, pain and eventually paralysis 
of the part, followed in many instances by atrophy of the affected 
muscles. 
If this line of reasoning be correct, we would anticipate the 
greatest changes in those muscles most violently exercised, hence 
in azoturia produced by locomotion we should expect the disease 
to exert its chief force upon the gluteals and the ilio-patellar 
group of muscles, while in a casting accident like that related 
the latter group would wholly escape, while the great dorsal 
muscles would prove the salient point of attack, the gluteals and 
posterior femuro-tibial group participating. 
In the typical case of azoturia one of the most evident symp¬ 
toms is the knuckling over of the posterior metatarso-phalangeal 
