We must next discuss _the organic disturbances that accompany feeling itself_. We know that feelings ‘express’ themselves in various ways; we blush for shame and pale from fear; we shake with rage, and our ‘heart beats high’ with hope. Now it is possible to measure all these organic changes; to record the rate and height of pulse, for instance, or the variation in the volume of a limb according as blood flows into it or is withdrawn from it; physiology puts the necessary instruments at our disposal. The observer may therefore be harnessed to some such system of recording apparatus, and may be subjected to some pleasant or unpleasant stimulus; he reports what he feels, and the experimenter is able to compare the report with the record from the instrument. The results of work of this sort are summed up in the following table; where a + stands for an increase, and a-for a decrease, of rate or height or volume, as the case may be. PLEASANT UNPLEASANT Rate of pulse - + Height of pulse + - Volume of arm + - Rate of breathing + - Depth of breathing ? - ? + The table asserts that, during a pleasant experience, our pulse is slowed and heightened; blood flows from the trunk into the extremities; and our breathing quickens and, perhaps, grows more shallow. During an unpleasant experience, the reverse of all these things takes place. The pleasant and unpleasant experiences here referred to are, of course, agreeable and disagreeable sense-feelings; and we have the right to correlate the organic changes with pleasant and unpleasant feeling only because they remain the same so long as feeling remains the same, whatever may be the character of the sensory stimulus. There can be no doubt that similar tables may presently be made out for the other sense-feelings; indeed, that must be the case, in so far as the sense-feelings are stable blends of simple feeling with sensations. But it is not easy, in the case of the other pairs, to secure a stable blend, to keep the nature of the ‘excitement’ or the ‘relaxation’ just the same from experiment to experiment; and we shall therefore make no attempt here to list their bodily expressions. We come back to the general subject of expression when we deal with emotion (§ 51).