He paused a moment, then resumed. "There are organs hidden deep in the body which do not reveal so easily the emotions. But the effect often outlasts the actual emotion. There are special methods by which one can study the feelings. That is what I have been doing here."
"But how can you?" I queried.
"There is what is called the sympathetic nervous system," he explained. "Above the kidney there are also glands called the suprarenal which excrete a substance known as adrenin. In extraordinarily small amounts adrenin affects this sympathetic system. In emotions of various kinds a reflex action is sent to the suprarenal glands which causes a pouring into the blood of adrenin.
"On the handkerchief of Gloria Brackett I obtained plenty of comparatively fresh blood. Here in this machine I have between these two pincers a minute segment of rabbit intestine."
He withdrew the solution from the cylinder with a pipette, then introduced some more of the dissolved blood from the handkerchief. The first effect was a strong contraction of the rabbit intestine, then in a minute or so the contractions became fairly even with the base line on the card.
"Such tissue," he remarked, "is noticeably affected by even one part in over a million of adrenin. See. Here, by the writing lever, the rhythmical contractions are recorded. Such a strip of tissue will live for hours, will contract and relax beautifully with a regular rhythm which, as you see, can be graphically recorded. This is my adrenin test."
Carefully he withdrew the ruled paper with its tracings.
"It's a very simple test after all," he said, laying beside this tracing another which he had made previously. "There you see the difference between what I may call 'quiet blood' and 'excited blood.'"
I looked at the two sets of tracings. Though they were markedly different, I did not, of course, understand what they meant. "What do they show to an expert?" I asked, perplexed.
"Fear," he answered laconically. "Gloria Brackett did not go voluntarily. She did not elope. She was forced to go!"