35G Meynoir upon Hair. 



basis, there is in hair a colouring Matter which may be se- 

 parated from it, ami the shade of it varies according to the 

 ooio.ur it shows. It is to this fat substance that M. Vau- 

 qutlin attributes the pliability, the elasticity* and the inal- 

 terability of hair. It is certainly also to the same substance 

 that they owe the property of burning so rapidly, and form- 

 ing soap so abundantly with the alkalis. 



After having treated the colouring matter of hair, he 

 endeavours to characterize the animal substance which 

 forms it, by comparing it with all those already known. 

 Without detailing all the experiments he made with this 

 view, we shall only say that it was not gelatine ; since the 

 solution in water, which is done with much trouble, never 

 becomes a jelly after evaporation : neither is it albumen; 

 because it cannot be dissolved in boiling water without 

 being decomposed, and the solutions act differently with 

 the reagents. 



. The humour which the substance of hair approaches most, 

 if not absolutely the same, is, according to M, Yauquelin, 

 that which physiologists denominate mucus, or animal mu- 

 cilage, which is neither gelatine nor albumen. 



This humour, which is separated in the nostrils, the mouth, 

 the oesophagus, the tracheal artery, the stomach, the bladder, 

 and in general in all the, cavities of the body, gives a great 

 deal of viscosity to water, and also the property of frothing 

 very strongly by agitation. In certain coriza it becomes 

 thready, like the substance of silk or spiders' webs ; pre- 

 serves its transparency and flexibility after desiccation ; and 

 M. Vauquclin does not doubt that if it contained a little 

 oil, it would completely resemble the substance of hair. 



The epidermis, the nails, corns, wool, and down in gene- 

 ral arc formed of .lie same animal mucus, and equally con- 

 tain in their composition a ceytain quantity of oil, which 

 gives them their elasticity and pliability. 



The beginning of some experiments undertaken by 

 M. Vauqr.elin upon the humour of the pHca polonica, which 

 was furnished him bv M. Alibcrt, physician of the hospital 

 of St. Louis, induced him to think that it was of the same 

 nature as the substance of hair ; and that it is what is super- 

 abundant to the formation of the latter. 



LVI. Thirty- 



