f mercury 150 millimetres, or 6 inches, in height."

Instruments for ascertaining the blood-pressure in human beings record
it merely for a moment or two. In experimenting upon a living animal,
an incision is made in the neck, the principal artery exposed and
severed, and connected with the recording instrument.

"Pain" is a word which as a rule the modern physiologist prefers to
exclude from his vocabulary. "We know absolutely nothing about pain
except that which we ourselves have suffered," says a leading
experimenter. We are unable neither to see, hear, smell, taste, or
feel the pain of another being, and although the cries or struggles of
an animal which is being vivisected may suggest that it is
experiencing intense agony, the physiologist insists that in reality
we know nothing about it, and we can only infer that it is
experiencing something which our reason suggests that we should feel
in its place. Of course we might say the same thing regarding agony
undergone by another human being. What the physiologist does is note
the phenomena following the stimulation of nerves, and to register it
by appropriate instruments.

To stimulate a nerve is to excite its activity in some way. When the
dentist touches with his instrument the exposed nerve of a tooth,
there is immediate "stimulation," as many of us have had reason to
assert, even if the dentist can know nothing of our sensations, and
can only infer them by remembering his own. One may stimulate the
nerve of a vivisected animal by mechanical means, by pinching or
scraping it when exposed; and although the movements of the animal may
indicate an exquisite sensibility, yet other methods are more
effective for the purposes of the experimenter. "Electricity,"
Professor Austin Flint tells us, "is the best means we have of
artificially exciting the nerves. Using electricity, we can regulate
with exquisite nicety the degree of stimulation. WE CAN EXCITE THE
NERVES LONG AFTER THEY HAVE CEASED TO RESPOND TO MECHANICAL
IRRITATION." A French vivisector, M. de Sine'ty, removed the breasts
of a female guinea-pig, nursing its young, and laid bare the mammary
nerve, and he tells us that "the animal exhibits signs of acute pain,
ESPECIALLY WHEN THE NERVE IS STIMULATED BY AN ELECTRIC CURRENT."[1]

[1] Gazette Me'dicale de Paris, 1879, p. 593.

In 1903 there was published in America an account of a large number of
vivisections involving blood-pressure which a well-known