70 On the Hair in Man 



other dermal coverings, shoot up or vegetate, not from the bulb 

 or root only, but grow also from the point. In proof of this, 

 at the meeting of the 22d of February last, he particularly in- 

 sisted upon the result observed after some careful experiments, 

 viz., that although hair cut clean across presents at first a 

 completely truncated extremity, yet at the end of several weeks 

 it acquires the form of a fine point. Hence he contends that 

 there is a movement of the nutritious juices in the interior of 

 the canal of each hair ; he is at the same time of opinion, that 

 the growth of the bulb is carried on by a kind of intus-susceptio. 

 In opposition to this view, M. Huzard remarked, that his fa- 

 ther having made some experiments on the effects of dyes 

 applied to the wool of living animals, was led also to make ob- 

 servations upon the growth of the wool ; and he found that 

 after having dyed the wool of one year's growth with one co- 

 lour, and tinged that of a second year with another, that at 

 the end of the third he could not perceive that the spaces 

 marking the growths of the previous years had increased in 

 the slightest degree, — whence it followed that the wool shot 

 out only at its base. 



Another point discussed, was the cause of the hair becoming 

 white ; and one or two additional facts, bearing on the point, 

 were mentioned. M. Koulin stated, that he was acquainted 

 with an individual, who, being terrified at the prospect of 

 losing his fortune, in one night the hair on one-half of his head 

 became white, the half being the one on which he had reposed. 

 M. Roulin also stated another very striking fact, quoted from 

 the London Magazine, viz., that a cock which had been cap- 

 tured by a fox, and rescued again in life, speedily lost all his 

 feathers, which, however, grew again, but all of a white colour. 

 The true cause of hair becoming white, in the estimation of 

 this gentleman, was the disappearance of the colouring oily 

 fluid, which generally' fills the tubes of the hair. This explana- 

 tion, however, in the opinion of M. Doyere, was in no degree 

 satisfactory, inasmuch as even although the absence of this co- 

 louring fluid were conceded, yet this would not render the hair 

 white but only transparent, and it is well known that hoary 

 hair is not only white but opaque also. 



But, by far the most interesting opinion elicited during these 



