CLASS. I. 1. 2. 4. OF IRRITATION. 19 



in some parts of the East, does not expend nearly so much sen- 

 sorial power, as when the warmth is produced by the locomo- 

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

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

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

 agitation of a horse to exercise on foot. And I suppose those, 

 who are unfortunately lost in snow, who are on foot, are liable 

 to perish sooner by being exhausted by their muscular exertions; 

 and might frequently preserve themselves by lying on the ground 

 and covering themselves with snow, before they were too much 

 exhausted by fatigue. See Botan. Garden, Vol. II. the note on 

 Barometz. 



M. Buffon made a curious experiment to shew this circum- 

 stance. He took a numerous brood of the butterflies of silk- 

 worms, some hundreds of which left their eggs on the same day 

 and hour; these he divided into two parcels; and placing one par- 

 cel in the south window, and the other in the north window of his 

 house, he observed, that those in the colder situation lived many 

 days longer than those in the warmer one. From these observa- 

 tions it appears, that the wearing of flannel clothing next the 

 skin, which is now so much in fashion, however useful it may 

 be in the winter to those, who have cold extremities, bad diges- 

 tions, or habitual coughs, must greatly debilitate them, if worn 

 in the warm months, producing fevers, eruptions, and premature 

 old age. See Sect. XXXVII. 5. Class I. 1. 2. 14. Art. III. 2. 1. 



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 strongly, after the 

 increased action of the absorbents of the bladder is somewhat 

 diminished. If the absorbents continue also to act strongly, the 

 urine is higher coloured, and so loaded as to deposit, when cool, 

 an earthy sediment, erroneously thought to be the material cause 

 of the disease; but is simply owing to the secretion of the kidneys 

 being great from their increased action; and the thinner parts 

 of it being absorbed by the increased action of the lymphatics, 

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

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

 from the kidneys in a very dilute state; as appears in those, 

 who from the stimulus of a stone, or other cause, 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-absorbed. The general use of this urinary ab- 

 sorption to the animal economy is evinced from the urinary blad- 

 ders of fish, which would otherwise be unnecessary. High co- 

 loured urine in large quantity shews only, that the secreting ves- 



