[Illustration: Figure 9.--Intestinal muscle beating in normal vena cava blood, removed at 1 and renewed at 2. At 3 normal blood removed. At 4 contraction inhibited by vena cava blood drawn after sensory stimulation; at 5 removed. At 6 Ringer’s solution substituted.] Confirmation of Our Results by Other Observers The foregoing experiments and conclusions were reported in 1911. In 1912, Elliott[45] brought confirmatory evidence by use of a method quite different from ours. As previously stated, he studied the effects of experimental procedures on adrenal secretion by a careful comparative quantitative assay of the adrenin content of the glands when one gland was isolated from the central nervous system and the other left connected. He took advantage of the action of morphia and of the substance Β-tetrahydronaphthylamine in evoking in cats all the appearances of great fright. After the animals had thus been “frightened,” he found that the adrenal gland which was still connected with the spinal cord was much depleted of its adrenin content compared with the other, isolated gland. And he observed, further, that animals newly brought to the laboratory, and evidently disturbed by the strangeness of their surroundings, had a considerably smaller amount of adrenin in their glands than other animals grown accustomed to the situation. Elliott also observed that prolonged excitation of a sensory nerve, such as the great sciatic, may cause the adrenin largely to disappear from the gland still connected with the central nervous system and subjected, therefore, to reflex influences. Our conclusions have also been confirmed more recently (1913) by Hitchings, Sloan and Austin,[46] working in Crile’s laboratory in Cleveland. They used the same method which we had used to obtain blood and to test for adrenin, and found that after great fear and rage had been induced in a cat by the attempt of a muzzled dog to fight it, the adrenin reaction was clearly demonstrable. And just as we had noted that the reaction did not occur if the adrenal glands had been removed, they showed that it did not occur if the nervous connections with the spinal cord were previously severed. The logic of all these experiments may be briefly summed up. That the adrenal glands are subject to splanchnic influence has been demonstrated anatomically and by the physiological effects of their secretion after artificial stimulation of the splanchnic nerves. Impulses are normally sent along these nerves, in the natural conditions of life, when animals become greatly excited, as in fear and rage and pain. There is every probability, therefore, that these glands are stimulated to extra secretion at such times. Both by an exceedingly delicate biological test (intestinal muscle) and by an examination of the glands themselves, clear evidence has been secured that in pain and deep emotion the glands do, in fact, pour out an excess of adrenin into the circulating blood.