the chair he had occupied, as I remembered "Mr. Haswell was telling
Dr. Scott something in an undertone. I could not hear it. But the old
man grasped the doctor by the wrist to pull him closer to whisper
to him. The doctor's hand was toward me and I noticed the peculiar
markings of the veins.

"You perhaps are not acquainted with the fact, but the markings of
the veins in the back of the hand are peculiar to each individual--as
infallible, indestructible, and ineffaceable as finger prints or the
shape of the ear. It is a system invented and developed by Professor
Tamassia of the University of Padua, Italy. A superficial observer
would say that all vein patterns were essentially similar, and many
have said so, but Tamassia has found each to be characteristic and
all subject to almost incredible diversities. There are six general
classes--in this case before us, two large veins crossed by a few
secondary veins forming a V with its base near the wrist.

"Already my suspicions had been aroused. I sketched the arrangement of
the veins standing out on that hand. I noted the same thing just now
on the hand that manipulated the fake apparatus in the laboratory.
Despite the difference in make-up Scott and Prescott are the same.

"The invisible rays of the ultra-violet light may have blinded Mr.
Haswell, even to the recognition of his own daughter, but you can
rest assured, Prescott, that the very cleverness of your scheme will
penetrate the eyes of the blindfolded goddess of justice. Burnham, if
you will have the kindness to summon the police, I will take all the
responsibility for the arrest of these people."