grown up sensible only to ranges of temperature mutually exclusive of each other. Assigning these ranges somewhat arbitrarily, for present illustration we might now construct the following schema[1] for our temperature aesthetics. At about -40° F. the heat tissue would be passive, the cold tissue violently active: we should suffer pains of cold. With increase of temperature the cold tissue would relax and its sensations abate; from this cause, at 68° the range of 'cold' pain would run out; at about 70 pleasure nerves start up in cold tissue; at 75° the pleasures of coolness a maximum; at 90° cold tissue so passive as to be affected only by great changes of temperature; consequently no further sensations from cold tissues. Turning to the heat tissue, we should have it beginning ordinary activity at about 60°; here indistinguishable feelings of warmth and agreeableness; 65° maximum of agreeable warmth; 75° pleasure range run out in heat tissue; at 72° pain range beginning to give indistinguishable discomfort; thence upward, heat and pain increase to unbearable limits.
Such a schema shows the pleasure ranges of the two tissues to overlap, and the ranges of pain and pleasure to overlap in each tissue; and in accordance with this, as we know, temperature from 70° to 75° is sometimes pleasurably warm, sometimes pleasurably cool, sometimes disagreeably warm, again disagreeably cool, and more often still is quite indifferent. All this last would be again explainable by two other facts. First, at this indifference region, both tissues would commonly be passive except to sudden changes of considerable extent; consequently no temperature sensations would here be commonly felt. Secondly, the moment of contractile inertia would be different under different conditions, and would depend upon the direction of the immediate changes of temperature with reference to the previous state or direction of the thermometer. The same abso-
- ↑ This schema may be graphically shown by a drawing with a graded thermometer in the middle; the space to the right of it representing heat tissue; that to the left cold tissue; contrary arrows on each side showing how tissues contract; separate triangles on each side representing each sensation, horizontal length of their bases proportional to intensity and each apex placed at the height where each sensation begins or ends.
