154 DR. C. E. BEEVOR AND MR. V. HORSLEY ON THE EXCITATION OF THE 
readily picked out,” and were situated as indicated by our previous observations. In 
the discussion that followed the reading of Dr. Nancrede’s paper, Dr. Morris J. 
Lewis, to whom had been intrusted the provision of the excitation, and, in part, 
observation of the effect, made the following important remarks. He said, “No effect 
was produced by the application to the cortex until the current was so strong as to 
produce powerful and painful tetany of his first dorsal interosseous muscle,” the skin 
being wet and metallic electrodes employed. The battery was “one of Flemming’s 
largest faradic batteries in perfect order, one half of the secondary coil being used with 
the graduating tube half withdrawn.” 
Finally, displacement of the electrodes laterally of the i^th of an inch “ caused the 
movement to cease,” showing how extremely focal the effect produced was. 
The objection to observation 1 does not apply in the same degree to observations 
2, 3, and 4, since in 2 and 3 a weak solution of perchloride of mercury, and in 4 
sterilised water was employed in irrigation of the surface of the brain. On collating 
the observations, moreover, they all point in the same direction, viz., that the repre¬ 
sentation of movement in Man is very integrated, be., in isolated areas, and requires 
powerful excitation for its deniunstration. 
Another example has recently occurred to one of us (V. H.) :— 
V. li.L. d, age 39, operated upon for focal ejiilepsy at the request of Sir James 
Crichton Browne, F.Ft.S. 
The attacks began with a confused aura in the left hand and upper limb, which was 
then raised at the shoulder in extension, the motor spasm spreading rapidly to 
the lower limb and face of the left side, and subsequently to the right side, but the left 
was far more affected, [t was concluded that a previous diffused injury to the head 
had caused lesion of the right so-called motor area, and that the focus for the move¬ 
ments of the shoulder was the starting point of the attack. 
The cortical area for the upper limb was therefore exj)osed. The dura mater having 
been raised carefully, the cortex was excited with platinum electrodes, 2 mm. apart, 
a secondary current being obtained from a Kronecker coil, furnished with a 
Helmholtz side wire, and siqtplied by a weak Grenet (bichromate) cell. 
The first excitation with the coil at 7000 gave no result, etherisation was then 
iliminished, but as no result followed a])pllcatlon of the electrodes to the point marked 
1 in the table on p. 155, the strength of the coil was raised to 8000, and subsequently 
to 9000 ; this last, together Avith diminished etherisation, produced a single movement 
of the thumb, consequently this strength of current was retained. Tested after the 
excitation was completed, this stimulus Avas found to be distinctly painful to the 
tongue and Avas, therefore, far in excess of tliat Avhich Avould have sufficed to produce 
general epileptic convulsions in the Bonnet Monkey. At the same time, it is 
interesting to note that the strength of current required to produce a moAmment 
from the cortex of the Orang- Avas intermediate between these tAvo extremes. 
The cortical surface exposed included the two central quarters of the Fissure of 
