Sect. XXXII. 3. 2. OF IRRITATION. 287 



face of the (kin, and on the internal furfaces of every cell or 

 interftice of the body ; then the expenfe of fenibrial power in 

 the venous abforption, by which the blood is received from the 

 capillary veffels, or glands, where the arterial power ceafes, and 

 is drunk up, and returned to the heart 5 next the expenfe of 

 fenforial power ufed by the mufcles of refpiration in their of- 

 fice of perpetually expanding the bronchia, or air-veflels, of the 

 lungs ; and laitly in the unceafmg periftaitic motions of the 

 ftomach and whole fyftem of interlines, and in ail the fecre- 

 tions of bile, gaftric juice, mucus, perfpirabie matter, and the 

 various excretions from the fyftem. If we conhder the ceafe- 

 lefs expenfe of fenforial power thus perpetually employed, it 

 will appear to be much greater in a day than all the voluntary 

 exertions of our mufcles and organs of fenle confume in a 

 week ; and all this without any fenfible fatigue ! Now, if but 

 apart of thefe vital motions are impeded, or totally flopped for 

 but a (hort time, we gain an idea that there mud be a great ac- 

 cumulation of fenforial power ; as its production in theie or- 

 gans, which are fubjeft to perpetual activity, 13 continued dur- 

 ing their quiefcence, and is in confequence accumulated. 



While, on the contrary, where thole vital organs aft too for- 

 cibly by increafe of ftimulus without a propordonally-increaied 

 production of fenforial power in the brain, it is evident, that a 

 great deficiency of aftion, that is torpor, muft foon follow, as 

 in fevers ; whereas the locomotive mufcles, which act only by 

 intervals, are neither liable to fo great accumulation of fenforial 

 power during their times of inactivity, nor to fo great an ex- 

 hauftion of it during their times of action. 



Thus, on going into a very cold bath, fuppofe at 33 degrees' 

 of heat on Fahrenheit's fcale, the action of the fubcutaneous 

 capillaries, or glands, and of the mouths of the cutaneous ab- 

 forbents is diminifhed, or ceafes for a time. Hence lefs or no 

 blood paffes thefe capillaries, and palenefs fucceeds. But foon 

 after emerging from the bath, a more floricl colour and a greater 

 degree of heat are generated on the Ikin than was poilelicd be- 

 fore immerfion - 9 for the capillary glands, after this quiefcent 

 ftate, occafioned by the want of ftimulus, become more irritable 

 than ufual to their natural ftimuli, owing to the accumulation of 

 fenforial power, and hence a greater quantity of blood is tranf- 

 mitted through them, and a greater fecretion of perfpirablt; 

 matter ; and, in confequence, a greater degree of heat fucceeds 

 During the continuance in cold water the breath is cold, and 

 the aft of refpiration quick and laborious ; which have gener- 

 ally been afcribed to the obftruftion of the circulating fluid by 

 a fpafm of the cutaneous vefTels, and by a canfequent accumu- 

 lation 



