EPFECIS OF THE POSITION OF A PART £77 
could be explained by the mere mechanical effect of the position of the part 
upon the blood in the vessels, and that the diminution of pressure upon their 
walls resulting from the action of gravity upon their contained blood must 
operate as a stimulus to the vaso-motor nervous apparatus of the limb, so as 
to induce reflex contraction of its arteries. 
I will now ask this man (with his arms bare) to raise one hand high into the 
air, while the other hangs beside him. You observe at once the striking contrast 
between the two. In the one elevated, not only have the veins entirely collapsed, 
but the colour is almost that of the limb of a corpse. So white is the hand as 
to imply that the minute arteries must surely be in the same state of extreme 
constriction as occurs during syncope. 
I will now apply to the arm close to the axilla a bandage of elastic webbing, 
putting on the first few turns with firmness and rapidity, so as to avoid any 
intermediate condition of engorgement through obstruction of the return by the 
veins before the arteries are completely compressed ; while the later turns may 
be put on, if we please, more leisurely and with less firmness, to ensure, by the 
accumulation of the elastic force, complete maintenance of such constriction 
of the limb as prevents all circulation. The elastic band having been fixed with 
a pin, the limb is lowered and the man will stand aside for a few minutes. 
I may state that, when Esmarch published his method of bloodless operating 
—consisting, as my hearers are all aware, of first expelling the blood from the limb 
by means of an elastic bandage wound firmly round it from the distal extremity 
upwards, and then applying another elastic constricting band in the manner 
you have witnessed just above the first, so as to prevent recurrence of circulation 
on the removal of the latter—I thankfully adopted the use of the upper con- 
stricting band in preference to the common tourniquet. I did so because the 
elastic band has the great superiority over the inelastic strap of the tourniquet, 
that it follows up any yielding that may occur in the soft parts subsequently 
to its application, and thus prevents the necessity which we often used to find 
with the common tourniquet, especially if the limb was swollen through inflam- 
matory or oedematous effusion, of tightening up the instrument repeatedly in 
consequence of recurrence of bleeding, attended on each occasion with venous 
engorgement. But, while I gratefully accepted this part of Professor Esmarch’s 
procedure, I did not see sufficient reason for substituting his mode of emptying 
the limb of blood by elastic bandaging for our former practice of trusting to the 
elevated position. I shall recur to this point in the sequel. 
Being desirous of testing with greater precision than was possible upon the 
human subject the correctness of the view which I had been led to entertain 
of the cause of the paleness of an elevated limb, I performed on November 29, 
LISTER I N 
