"Then," said my companion, "make no further investigations in this direction."
"But I wish to verify the experiment," I replied. "Although it is not a pleasant test, I can not withstand the temptation to repeat it."
And again I moved the candle backward and forward, when the figure of my brain sprung at once into existence.
"It is more vivid," I said; "I see it plainer, and more quickly than before."
"Beware of the science of man I repeat," he replied; "now, before you are deep in the toils, and can not foresee the end, beware of the science of human biology. Remember the story recently related, that of the physician who was led to destruction by the alluring voice."
I made no reply, but stood with my face fixed, slowly moving the candle backward and forward, gazing intently into the depths of my own brain.
After a time the old man removed the candle from my hand, and said: "Do you accept the fact? Have I demonstrated the truth of the assertion?"
"Yes," I replied; "but tell me further, now that you have excited my interest, have I seen and learned all that man can discover in this direction?"
"No; you have seen but a small portion of the brain convolutions, only those that lie directly back of the optic nerve. By systematic research, under proper conditions, every part of the living brain may become as plainly pictured as that which you have seen."
"And is that all that could be learned?" I asked.
"No," he continued. "Further development may enable men to picture the figures engraved on the convolutions, and at last to read the thoughts that are engraved within the brains of others, and thus through material investigation the observer will perceive the recorded thought of another person. An instrument capable of searching and illuminating the retina could be easily affixed to the eye of a criminal, after which, if the mind of the person operated upon were stimulated by the suggestion of an occurrence either remote or recent, the mind faculty would excite the brain, produce the record, and spread the circumstances as a
