276 THE SOLIDS. 



by a certain degree of erection of the hair, but not indeed to 

 such an extent as to cause it " to stand an end." Now this 

 erection is the result of the distribution of fibres of elastic 

 and contractile tissue throughout the substance of the corium, 

 and which interlacing amongst the hair follicles, occasion the 

 erection of the hairs themselves". 



The distribution of these fibres, and their connexion with 

 the bases of the hairs, are well seen in the skin of the hog. 



COLOUR OF HAIR. 



The colour of the hair depends upon the same cause as 

 that of the skin and eye, and is due to the presence of pigment 

 granules and cells; these are contained principally in the 

 medullary canal, but are also interspersed between the fibres 

 of the stem ; they first become manifest in the upper portion 

 of the bulb of the hair. 



The depth of the colour of the hair very generally bears 

 a relation to the development of pigmentary matter in other 

 parts of the system, as in tfye eye and beneath the skin. To 

 this rule, however, some remarkable exceptions are occa- 

 sionally encountered. 



The colour of the lighter hairs, as the red and flaxen, 

 would appear to depend less upon the number and depth of 

 colouring of the pigment cells and granules, than upon the 

 presence of minute globules of a coloured oil. 



In the hair of Albinoes but little colouring matter is pre- 

 sent, and in grey hairs also, the colour has deserted the pig- 

 ment cells and granules. 



Hair is decolorised by long contact with chlorine. 

 It is generally stated as an undoubted fact, that the hair 

 may turn white or become colourless under the influence of 

 strong and depressing mental emotions in the course of a 

 single night. This singular change, if it does ever occur 

 in the short space of time referred to, can only be the result 

 of the transmission of a fluid possessing strong bleaching pro- 

 perties along the entire length of the hair, and which is 

 secreted in certain peculiar states of the mind. 



