Page:Mind (Old Series) Volume 11.djvu/381

380 J. M. CATTELL not be distinguished, at 30<r for B, 50 for C, and the will-time in these and similar experiments at the same. The reaction was made with the speech-organs in quite the same manner. When the white surface was seen the observer said ' Weiss ' and the hands of the chronoscope were stopped by means of the lip-key or sound-key. When no white surface was present the observer said nothing, and the hands ran on until the experimenter stopped the clockwork. TABLE XIII. SOUND-KEY. LIP-KEY. B C B C R R' R R' R R' R R' 3. IV 246 255 234 247 248 241 247 237 244 246 282 302 274 264 274 281 308 268 264 268 236 241 233 243 244 241 246 235 248 245 276 281 256 263 256 275 276 250 263 256 4 5 7 A 246 243 279 278 239 243 266 264 AV 20 11 18 12 14 9 18 12 We have seen that the motor-time is longer when a simple reaction is made with the speech-organs than when it is made with the hand. There is no reason why the perception and will- time found by subtracting the simple reaction-time (Table III.) from the time here measured should not be the same as when the reaction was made with the hand. If we average together the determinations with the sound-key and lip-key we get 65a for B, 100 for C, which agrees very well with the determinations made with the hand. If instead of two black cards on one of which there is a white surface, we take two white cards on one of which there is a black surface, and let the observer react only when the black is present, the conditions are substantially as before ; the perception may require slightly longer, the will-time is probably the same. The results of such experiments are given in Table XIV. If, instead of black, we place a colour on the white card, the perception becomes slightly more difficult ; it is not quite so easy to see that something is there when it is yellow as when it is black, the will-time however presumedly remains the same. In one series of experiments (to the left in Table XV.) only one colour was used at a time, in a second series (right in Table