0\ HUMAN HAIR. J45 



From the experiments related in the JNIcmoir of Mr, 

 Vaiiqueliu, a great niimber of which, being merely ac- 

 cessory to the principal object, we have omitted, it ap- 

 pears, that black hair is formed of nine dtllereut sub- 

 stances, namely: 



I All animal matter, which constitutes the greater Constituent 

 pjjj.^. parts of black 



^ ' . , . ., . ,, . hair. 



2. A white concrete oil in small quantity : 



3. Another oil of a greyish green colour, more abun- 

 dant than the former; 



4. Iron, the state of which in the hair is uncertain; 



5. A few particles of oxide of manganese; 

 f). Phosphate of lime; 



7. Carbonate of lime in very small quantity ; 



f^. Silex, in a conspicuous quantity ; 



0. Lastly, a considerable quantity of sulphur. 



The same experiments shew, that red hair diiiers from Difference of 

 black only in containing a red oil instead of a blackish "^^ ' 



green oil; and that M'hite hair differs from both these and of white, 

 only in the oil being nearly colourless, and in containing 

 phosphate of magnesia, which is not found in them. 



From this knowledge of the nature of the constituent Causes of the 



principles of hair Mr. V'auquelin thinks we may account ^'?^**^^^^.°f 

 *. , . ,,...,. . colourin hair, 



lor the various colours that distinguish it. Acc?ording to 



him the black colour will be owing to a black ;iflid as it 

 were bituminous oil, and perhaps likewise to a combina- 

 tion of sulphur with iron. Carotty and llaxcii hair will 

 be occasioned by the pre^tmce of a red or yellow oil, 

 which when deepest, and mixed with a small quantity of 

 brown oil, produces the dark red hair. Lastly, white 

 hair is owing to the absence of the black oil and sulphur- 

 ated iron, lie believes, that in the carrotty and Haxen, 

 as well as in the white, there js always an excess of sul- 

 phur j since, on the application of white metaHic oxides Blackened by 

 to thein, such as those of mercury, lead, bismuth, ^'C, ^letallic oxides, 

 they grow black very speedily. The manneiF in which 

 this substance acts on metallic bodies leads him to suspect, 

 that it is combined with hidrogeUf 



Mr. V'auquelin attempts next to explain the whiteness Wh'teness sud- 

 produced suddenly in the hair of persons struck with ^^"'J^P^"^^"^^** 

 Tjro found grief or great terror. To explain tliis, he says, 



Vol. XV.— Oct. 1806. U we 



