uncertainty the less power of conscious self-analysis and control.

It will occur to the reader that in all the instances given above,
different individuals attain the unconscious stage of perfect
knowledge with very different degrees of facility. Some have to
attain it with a great sum; others are free born. Some learn to
play, to read, write, and talk, with hardly an effort--some show such
an instinctive aptitude for arithmetic that, like Zerah Colburn, at
eight years old, they achieve results without instruction, which in
the case of most people would require a long education. The account
of Zerah Colburn, as quoted from Mr. Baily in Dr. Carpenter's "Mental
Physiology," may perhaps be given here.

"He raised any number consisting of ONE figure progressively to the
tenth power, giving the results (by actual multiplication and not by
memory) FASTER THAN THEY COULD BE SET DOWN IN FIGURES by the person
appointed to record them. He raised the number 8 progressively to
the SIXTEENTH power, and in naming the last result, which consisted
of 15 figures, he was right in every one. Some numbers consisting of
TWO figures he raised as high as the eighth power, though he found a
difficulty in proceeding when the products became very large.

"On being asked the SQUARE ROOT of 106,929, he answered 327 before
the original number could be written down. He was then required to
find the cube root of 268,336,125, and with equal facility and
promptness he replied 645.

"He was asked how many minutes there are in 48 years, and before the
question could be taken down he replied 25,228,800, and immediately
afterwards he gave the correct number of seconds.