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 experimenter had made, either personally or by his assistants. The number of dogs thus sacrificed was no less than 243; the experiments to which they were subjected amounted to 251. Ether alone was used in 107 experiments, or about 43 per cent. of the whole number; ether and morphia were employed in 80 experiments, or 32 per cent. of the total. Chloroform combined with ether was used but ONCE. In no less than 15 per cent. of the experiments no anaesthetic whatever is named, and CURARE was employed in nearly 10 per cent. of the investigations. Why was curare used? We have seen that the professor of physiology in Upsaal University regards it as "the most cruel of poisons." An animal under its influence, Professor Holmgren tells us, "changes instantly into a living corpse, WHICH HEARS AND SEES AND KNOWS EVERYTHING, but is unable to move a single muscle, and under its influence no creature can give the faintest indication of its hopeless condition." The French vivisector, Claude Be'rnard, tells us frankly that death under the influence of this poison "is accompanied by sufferings the most atrocious that the imagination of man can conceive." Precisely the reason why this poison was employed in the investigations before us we have no means of knowing by anything the vivisector has stated in his report. He tells us, indeed, that "the animals were all reduced to full surgical anaesthesia before the experiments began, a nd were killed before recovery from the same." We see no reason for doubting why this may not have been true. It is quite probably that as a rule the preliminary cutting operations necessary were made while the animal was deeply insensible. But was this deep insensibility maintained for hours? Was it so absolute that doubt is impossible? Since it is certain that the irritation produces a rise in blood- pressure, was this phenomenon never witnessed during the terrible operations to which these dogs were subjected for hours at a time? If, as Professor Langley of the University of Cambridge explained, pain "WOULD CAUSE A RISE OF BLOOD-PRESSURE," was this sign of agony ever evoked when the bare nerve was subjected to "stimulation," or the paws "slowly scorched" one after another? Let us see.
We observe that as a rule each vivisection consisted of two procedures, aside from the preliminary operation. In the first place, the normal pressure of the blood was reduced by various methods, calculated to depress the vital powers of the animal, and to induce a condition of collapse, and this was followed by such "stimulation" of nerves as would tend to cause the blood-pressure to rise in an animal not perfectly anaesthetized. The means taken to depress the vital powers were as varied as the ingenuity of the vivisectors could devise. Sometimes it was accomplished by skinning the animal alive, a par of the body at a time, and then roughly "sponging" the denuded surface. Sometimes it was secured by crushing the dog's paws, first one and then the other. Now and then the dog's feet were burnt, or the intestines exposed and roughly manipulated; the tail was crushed, the limbs amputated, the stomach cut out. Then came the "stimulation" of the exposed nerve, carried on and repeated sometimes until Nature refused longer to respond, and death came to the creature's relief. No torments more exquisite were ever perpetrated unless absence of feeling was completely secured. Was it so secured? Let the experimenter's own report give us the facts, remembering that if there was pain, "THE BLOOD-PRESSURE WOULD RISE."
EXPERIMENT 42. The material used was a little dog, weighing only 11 pounds. How it was "reduced to shock"—whether by skinning or crushing—we are not informed; all we know is that it was "reduced to shock." The sciatic nerve was exposed, the artery in the neck laid bare, and the instrument for measuring the blood-pressure carefully adjusted. Ether, we are told, was used. Was all sensibility thereby wholly suppressed? Let us see what is revealed by the changes of the blood-pressure.[1]
[1] In all experiments cited in this chapter the italics are not in the original descriptions.
"10.30 a.m. Sciatic nerve stimulated. SLOW RISE IN BLOOD-PRESSURE.
10.35 a.m. Sciatic nerve stimulated. RISE OF BLOOD-PRESSURE.
10.51 a.m. Sciatic nerve stimulated. RISE OF BLOOD-PRESSURE.
11.30 a.m. Sciatic nerve stimulated. RISE OF BLOOD-PRESSURE
13 MILLIMETRES.
11.59 a.m. Sciatic nerve stimulated. RISE OF BLOOD-PRESSURE
5 MILLIMETRES."
Noon has come. It is the hour when experimenters need their accustomed refreshment, and we note a long interval during which there were no observations. The victim lies stretched upon the rack. After nearly two hours the pastime began again, or, we may say, "the young scientists resumed their arduous labours."