IIAIH AND FEATHERS. 303 



Water containing only four per cent, of potash dissolves 

 hair, while hydrosulphuret of ammonia is evolved. If the hair 

 he black, a thick dark-coloured oil, with some sulphur and iron 

 remains undissolved ; if the hair be red there remains a yellow 

 oil, with some sulphur and an atom or two of iron. When acids 

 are dropped into this solution, they throw down a white matter 

 soluble in an excess of acid. 



Sulphuric and muriatic acids become red when first poured on 

 hair, and gradually dissolve it. Nitric acid turns hair yellow and 

 dissolves it, while an oil separates, which is red or black accord- 

 ing to the colour of the hair dissolved. The solution yields a 

 great deal of oxalic acid, and contains, besides, bitter principle, 

 iron, and sulphuric acid. Chlorine first whitens hair, and then 

 reduces it to a substance of the consistence of turpentine, and 

 partly soluble in alcohol. 



When alcohol is digested on black hair, it extracts from it two 

 kinds of oil. The first, which is white, subsides in white shining 

 scales as the liquor cools ; the second is obtained by evaporating 

 the alcohol. It has a greyish-green colour, and at last becomes 

 solid. From red hair alcohol likewise separates two oils : the 

 first white, as from black hair, and the other as red as blood. 

 When the red hair is deprived of this oil, it becomes of a chest- 

 nut colour. Hence its red colour is obviously owing to the 

 red oil. 



When hair is incinerated, it yields iron and manganese, phos- 

 phate, sulphate, and carbonate of lime, muriate of soda, and a 

 considerable portion of silica. The ashes of red hair contain less 

 iron and manganese : those of white hair still less ; but in them 

 we find magnesia, which is wanting in the other varieties of hair. 

 The ashes of hair do not exceed 0*015 of the hair. 



From the preceding experiments of Vauquelin, we learn that 

 black hair is composed of the nine following substances : 



1. An animal matter constituting the greatest part. 

 - 2. A white solid oil, small in quantity. 



3. A greyish-green oil, more abundant 



4. Iron ; state unknown. 



5. Oxide of manganese. 



6. Phosphate of lime. 



7. Carbonate of lime, very scanty. 



8. Silica. 



9. Sulphur. 



