106 



It is unnecessary to linger long upon the physical qualities of hairs. 

 Like all fibrous bodies, they are possessed of great strength. In two 

 experiments, I found the average suspending power of a man's hair was 

 1200 grains; of the female, 1130. This is liable to vary with the 

 individual, and the freshness of the hair. That which is old and dry 

 does not possess one-half the strength of the recent. 



Its elasticity is very considerable, as may readily be shown, by pulling 

 a hair between the fingers. 



It is of all tissues of the body perhaps the least influenced by 

 decomposition. If taken into the stomach, it will remain for years 

 undigested, and if the body be buried with it, it will remain long after 

 flesh and bones have crumbled away and perished. 



Electricity can be readily excited by rubbing hairs, as is well known 

 to school boys, who occasionally catch a cat, to stroke her the wrong way 

 of the fur : a slight crackling and electric light are produced thereby, if 

 the experiment be conducted in the dai'k on a dry evening. The same 

 thing may often be witnessed when an individual combs his or her hair 

 before the glass, on a dark frosty night. 



Hairs have a great affinity for moisture, and consequently become, to 

 a great measure, indicators of the quantity existing in the atmosphere. 

 Many a lady is unable to keep her hair curled on a damp day, who can 

 do so readily on a dry one. 



It is this property of the hair to which we look to explain the pheno- 

 menon of its growth after death. 



At one time there was some doubt upon this point. Our forefathers 

 believed that it did grow after death, in many instances, and considered 

 it as a proof of the buried having been a grievous sinner. Their des- 

 cendants called the assertion into question, but experience has decided 

 the fact, and it is now established that, in many instances, where a per- 

 son has been shaved after death, the hairs have attained a con- 

 siderable altitude above the skin in the course of a day or two. 



This is accounted for, in the first place, by the strong affinity the hair 

 has for moisture, by which it is sensibly elongated ; and, in the second 

 place, by the gradual diminution of the thickness of the skin, produced 

 partly by the blood leaving the capillaries, and partly by actual evapora- 

 tion of the watery particles it contains. 



The change of colour effected by certain dyes, and by bleaching agents, 

 is extremely interesting, but I must content myself with refemng to 

 works of medical jurisprudence those who wish for full information on 

 the subject. 



A few words will suffice upon the uses of hair. In the higher animals 



