On the Mechanism of Chemical Temperature Regulation. 205 



shiver. The importance of shivering has been especially insisted on by 

 Loewy (19), by Kichet (20), and by Johansson (21), who gives a complete sketch 



Fig. 2.— Eabbit, 950 grin. 



A. Abscissa, rectal temperature. Ordinate, 2 consumption per 10 minutes. The x 



indicates observations while shivering. The points indicate observations while not 

 shivering. 



B. Abscissa, skin temperature. Ordinate, " extra oxygen." 



of the literature of the subject. Rubner (22) believes the significance of 

 shivering to be much exaggerated. 



Having found that the anaesthetised animal produced extra O2 in propor- 

 tion to the extent to which its skin temperature had fallen below a certain 

 fixed standard, it had to.be determined how the animal was aware of the 

 standard to which it should aim. The mechanism was in part revealed by 

 the following experiment. A cat was warmed in the water bath in the usual 

 manner, the O2 consumption being continuously determined and the 

 heating continued as usual beyond the shivering point. It was then-, 

 removed from the bath, with the result that the skin cooled rapidly below 

 the shivering point without any muscular activity appearing. The body 

 temperature followed the skin temperature slowly, and when this had 

 fallen below the point at which regulation previously ceased, violent 

 shivering set in, and extra oxygen was consumed in proportion to the 

 extent to which the skin temperature was below that point. The appearance 

 of chemical regulation is conditioned by the body temperature being below 

 a fixed point, its amount is determined by the extent to which the sub- 

 cutaneous temperature is below that point. Though among a number of 

 experiments of this type I have met none in contradiction with this view, 

 the results are not always so satisfactory as in that from which fig. 3 is 

 taken. It frequently happens that the animal cooling regulates for a 

 different temperature, generally lower, than that to which it regulated on 



