92 PERSONAL APPEARANCES IN HEALTH AND DISEASE. 



will stain the skin and tissues. Of these, silver is the 

 most notable example ; and people who have taken this 

 metal medicinally for a long period, are liable to have the 

 skin of their face changed to a bluish leaden hue from 

 the action of the light upon the silver. And one of the 

 most marked effects of chronic lead poisoning is the 

 appearance of a line of bluish discoloration along the 

 thin part of the gums where these border on the teeth. 



Then many disorders of the skin which give rise to 

 irritation, congestion, or inflammation, leave behind them 

 permanent yellow or brownish marks of discoloration. 

 There is one common affection which is accompanied by 

 a yellowish pigmentation. It is due to the presence of a 

 fungus on the skin, and occurs on the body favoured by 

 clothing and uncleanliness. It is readily removable. 



CHAPTER IX. 



ON < TEMPERAMENT/ ' HABIT/ AND i TONE.' 



FROM the earliest times it has been matte;* of faith among 

 writers on medicine that all mankind can be subdivided 

 into a few groups, each with sharply-marked charac- 

 teristics, and each with certain tendencies to particular 

 affections. How much truth underlies this doctrine it is 

 needless to inquire. Let it suffice that even now we 

 recognise the types of constitution which so long ago 



