IN HUMAN PHYSIOLOGY. 157 



22. Which should be clothed the warmer, a merchant or 

 a farmer ? 



The merchant is liable to more sudden and violent 

 changes of temperature, and his body is less likely to be 

 hardened by exposure and habit to resist them. 



23. Why should we not crack nuts with our teeth ? 



The brittle enamel is very liable to crack, and once 

 broken can never be restored. 



24. Do the edges of the upper and lower teeth meet 1 } 



(See Question 21.) 



25. When fatigued, would you take a cold bath ? 



Certainly not. The system is not vigorous enough to 

 produce a reaction, and the effect might be dangerous. 



26. Why is the outer surface of a kid glove finer than the 

 inner ? 



This illustrates the difference in texture between the 

 cutis and cuticle ; the dermis and epidermis. 



27. Why will a brunette endure the sun's rays better than 

 a blonde ? 



(See Physiology, page 63.) 



The skin is perhaps of a coarser texture, and not so 

 sensitive to heat. May it not be also that the black pig- 

 ment absorbs the heat and radiates it again rather than 

 transmits it directly to the internal organs ? It has also 

 been suggested that there is an increased flow of blood 

 in the darker skin, and hence increased perspiration. 



