Special attention was given to the relation of the errors made when
the fingers were near together to those made when the fingers were
spread. For this purpose a series of experiments was made with the
fingers close together, and then the series was repeated with the
fingers spread as far as possible without the subject's feeling any
strain. Each subject was experimented on one hour a week for about
three months. The same kind of stimulation was given when the fingers
were near together as was given when they were spread. The figures
given below represent the average percentage of errors for four
subjects.

Of the total number of answers given by all subjects when the fingers
were close together, 70 per cent. were wrong. An answer was called
wrong whenever the subject failed to judge the number correctly. In
making out the figures I did not take into account the nature of the
errors. Whether involving too many or too few the answer was called
wrong. Counting up the number of wrong answers when the fingers were
spread, I found that 28 per cent. of the total number of answers were
wrong. This means simply that when the fingers were near together
there were more than twice as many errors as there were when they were
spread, in spite of the fact that each finger was stimulated in the
same way in each case.

A similar experiment was tried using the two middle fingers only. In
this case not more than four contacts could be made at once, and hence
we should expect a smaller number of errors, but we should expect
still to find more of them when the fingers are near together than
when they are spread. I found that 49 per cent. of the answers were
wrong when the fingers were near together and 20 per cent. were wrong
when they were spread. It happens that this ratio is approximately the