Mi'moir upon Hair. 353 



hair, leaving a black residue formed of thick oil, a little 

 more annualized, and of iron and sulphur. There remains, 

 after the solutipn of red hair, a yellow oil, containing sul- 

 phur and an atom of iron. 



The acids form in these solutions white precipitates, solu- 

 ble ui an excess of the above menstrua. These precipitates 

 being; redissolved in the acids, there appeared upon the li- 

 quor, after some time, an oil under the form of a prismatic - 

 coloured pellicle. 



Tr.e solution of hair in potash precipitates lead of a 

 black colour, owing to the hydrosulphuret it contains ; that 

 of red hair appears to contain more of it. When they are 

 freed from the sulphur by exposure to the air, they have 

 nierelv the smell of soap, and become frothy in the same 

 manner. 



The acids act upon hair each in their own manner : the 

 sulphuric acid and the muriatic acid assume at first a very fine 

 rose colour, and afterwards dissolve it. The nitric acid 

 makes it yellow, and dissolves it also by means of a gentle 

 heat : the solution presents at its surface a black oil when 

 black hair is used, and a red oil when red hair is made use 

 of. Both the one and the oilier of these oils become white 

 after some time, and become concrete by cold. 



This same solution evaporated properly yields a good deal 

 of oxalic acid, and the uncrystallizable mother-water con- 

 tains a bitter substance, plenty of iron, and sulphuric acid 

 coming from the sulphur of the hair. 



The solution of red hair in the nitric acid contains less 

 iron, but more sulphuric acid than that of black hair. 



The oxygenated muriatic acid gas whitens hair at first, 

 afterwards softens it, and reduces it to the form of a viscous 

 and transparent paste like turpentine. This matter is bitter ; 

 it is partlv dissolved in water and partly in alcohol. 



I obtained from hair submitted to the fire in a close ap- 

 paratus the same products as from every other animal mat- 

 ter, with this difference ; that it furnished more sulphur 

 and yielded but very little gas : it left in the retort from £8 

 to 30 per cent, of charcoal. 



By incineration hair furnished iron and manganese, which 

 Vol. 35. No. loo. Sept. 180C. A a g^ve 



