CLASS L i. 2. 4- OF IRRITATION. 19 



in fome parts of the Haft, does not expend nearly fo much 

 ! power, as when the warmth is produced by the loc 

 tion of the whole weight of the body by mufcular action, as in 

 walking, or running, or fwimming. Whence the warmth of a 

 fire is to be preferred to flannel {khts for weak people, and the 



.tion of a horfe : to exereife on foot. And I fuppofe v 

 who are unfortunately loft in fnow, who are on foot, are 

 to perifli fooner by being exhaufted by their mufcular exertions ; 

 and might frequently preferve themfelves by lying on the ground, 

 .and covering themfelves with fnow, before they were too much, 

 exhaufted by fatigue. See Botari. Garden, Vol. II. the note on 

 netz. 



M. BuiTon made a curious experiment to (hew this 

 fiance. He took a numerous brood of the butterflies of 

 worms, fome hundreds of which left their eggs on the fame day 

 and hour ; thefe he divided into two parcels ; and placing on 

 eel in the fouth window, and the other in the north window - 

 houfe, he obferved, that thofe in the colder iituation lived many 

 days longer than thofe in the warmer one. From thefe obferva- 

 tioni.it appears, tLat the wearing of flannel clothing next the fkin, 

 which is now fo much in falhion, however ufefui it may be in 

 the winter to thofe, who have cold extremities, bad digeftions, or 

 habitual coughs, muft greatly debilitate them, if worn in the warm 

 months, producing fevers, eruptions, and premature old age. 

 See Sea. XXXVII. 5. Clafs I. i. 2. 14. Art. III. 2. i. 



4. Urina uberior colorata. Copious coloured urine. To- 

 wards the end of fever-fits a large quantity of high coloured 

 urine is voided, the kidneys continuing to act ftrongly, after the 

 increafed action of the abforbents of the bladder is fume; 

 diminifhed. If the abforbents continue alfo to aft ftrongly, the 

 urine is higher coloured, and fo leaded as to depofit, when cool, 

 an earthy fediment, erroneoufly thought to be the material caufe 

 of the difeafe j but is fimply owing to the fecretion of the kid 

 being great from their increafed action ; and the thinner parts 

 of it being abforbed by the increafed action of the lymphatics, 

 which are fpread very thick on the neck of the bladder ; for the 

 urine, as well as perhaps all the other fecreted fluids, is produced 

 from the kidneys in a very dilute ftate ; as appears in thofe, 

 who from the ftimulus of a ftone, or other caufe, evacuate their 

 urine too frequently; which is then pale from its not having 

 remained in the bladder long enough for the more aqueous part 

 to have been re-abforbed. The general ufe of this urinary ab- 

 forption to the animal ceconomy is evinced from the urinary blad- 

 ders of fifh, which would otherwife be unneceflary. High col- 

 oured urine in large quantity fhews only, that the fecreting vef- 



