62 THE HAIR. 



acids. Mulder also regards the substance of the hair as a sulpha- 

 mide compound. No conclusions can be drawn from any analyses 

 hitherto made in reference to the nature of the individual consti- 

 tuents of the hair, as, for instance, its connective tissue, cell- 

 contents, &c. 



Notwithstanding the closest search, Lae'r was unable to discover 

 any special pigment in the hair, although the microscopical exa- 

 mination of the cortical substance of differently coloured hairs 

 that is to say, the existence of certain coloured molecules indicates 

 the presence of a definite pigment. It is, however, well known 

 that white hair is especially rich in air, and that to this circum- 

 stance it mainly owes its glistening colour. Lae'r has further 

 shown by numerous experiments on differently coloured hair that 

 the iron which is present, and to which Vauquelin had drawn 

 attention, exerts no influence whatever on its colour. 



Lae'r found nothing but margarin, margaric acid, and olein in 

 the fat extracted from hair ; this fat had an odour of hair, or rather 

 of sweat. 



The amount of ash in the hair differs very much, although it 

 does not bear any relation to the colour, or any other property of 

 the hair. Lae'r found from 0*54 to 1'85J- of ash in the hair, and 

 from 0*058 to 0'390J of peroxide of iron, but he could not detect 

 manganese ; he found, however, some silica with phosphate of lime. 

 Von Gorup-Besanez,* who has made a very elaborate examination 

 of the quantity of silica in the hair, found that the hair of animals 

 contained on an average a much larger amount of this substance 

 than human hair (the latter containing only from 0*11 to 0*22^, 

 whilst the former contained from 0*12 to 0*5 7#). 



Wool and bristles do not differ essentially in their composition 

 from hair : the chemical constitution of feathers has, however, been 

 found by Scherer to differ very considerably from horny tissues 

 generally, and from hair especially. He found as the mean of 

 two analyses of the beard and the quill, 52'448^ of carbon, 7'161g 

 of hydrogen, and l7*787iF of nitrogen. Gorup-Besanez found con- 

 siderable quantities of silica in feathers. He has treated, in a most 

 careful and complete monograph, of the influence of the most 

 varied physiological relations, such as sex, age, mode of life, 

 species, &c., on the quantity of silica in the feathers. 



* Ann. d. Ch. u. Pharm. Bd. 66, S. 321-342. 



