238 
Proceedings of the Royal Society of Edinburgh. [Sess. 
tuning fork, although with increased speed of writing the amplitude of the 
pressure changes sensibly diminishes. The rhythm is also shown in 
children’s writing from about the age of ten, but the irregularities are very 
marked. It is difficult to get any reliable results with our grip pressure 
apparatus at an earlier age. Analogous phenomena appear in the case 
of point pressure. The point pressure trace of adult writing shows a 
characteristic “ rippled ” top on each wave of pressure, indicating more or 
less rhythmical increase and diminution of pressure. In the child’s writing 
this characteristic is entirely absent before the age of about eleven, and we 
have for our pressure trace either a more or less continuous line, or a line 
that is simply “ crooked,” without any regularity in its crookedness. These 
phenomena are probably in the main phenomena of co-ordination, but they 
also have a psychological interest, as we shall see presently. 
A second characteristic difference between adult and child writing may 
be regarded as due partly also to co-ordination phenomena and partly to 
psychical phenomena. It is well known that the practised reader does not 
recognise the several letters of a word individually, nor does he speak them 
individually, in reading a word, but reads the word, as it were, with a single 
total impulse, either of recognition or of speech. Similarly, the adult writer 
writes a word, not with a separate impulse for each letter, but with a single 
impulse for the whole word. In learning to write, however, the child 
learns first to draw the shapes of the letters, and there is a separate impulse 
for each stroke or letter or group of letters, according to the drawing unit 
with which the child is dealing, and this gradually changes from the stroke 
to the letter, from the letter to the group of letters, from the group of 
letters to the whole word, as the child progresses. These differences are 
well indicated in the point pressure traces. The adult trace shows at once 
that each word is written as a whole. The child, learning to write, shows 
equally unmistakably the units for which there is a single drawing 
impulse. 
Even when the child is taught from the beginning to write continuously, 
the traces can still be easily distinguished by the lack of rhythmical 
pressure variations in the child’s trace. This difference, although in the 
main a phenomenon of co-ordination, is at the same time indicative of the 
nature of the psychical impulse that guides the writing. It is due in part 
to the fact that writing is a form of language, while drawing is not. The. 
rhythm is present because it is the word that is before consciousness, not 
the shape or figure to be drawn. 
Moreover, the language unit is the sentence, not the word, and this 
is generally clearly shown both in speech and in reading. Are there any 
