148 
ON  HAIR  AND  HORNY  SUBSTANCES. 
Hair,  as  well  as  the  horny  substances,  is  free  from  phosphorus  ; 
they  contain  sulphur  in  variable  proportions,  which  the  author 
has  estimated  in  the  following  manner ;  the  substance  divided  as 
much  as  possible,  was  burned  with  saltpetre  containing  carbonate 
of  soda,  the  residue  having  been  treated  with  nitric  acid  at  the 
boiling  temperature,  the  estimation  is  made  by  means  of  chloride 
of  barium. 
The  following  numbers  refer  to  the  sulphur  contained  in  100 
parts  of  dried  hair  ;  two  estimations  were  most  frequently  made 
of  the  same  substance  :- — 
Human  hair.  Sulphur  per  cent. 
"Woman  of  93,  grey  hair,  formerly  fair      .     .  4-30 
"         93,  dark  brown,  mixed  with  grey  .  4-17 
"         87,  grey  hair   4-76 
"         84,  white  hair        .       .       .     .  4-30 
Man  of     81,  white  hair        ....  5*76 
"         80,  white  hair        .       .       .     .  4 '62 
Woman  of  71,  grey  hair  ....  4-08 
Man  of     49,  chesnut,  mixed  with  grey    .     .  4*63 
Woman  of  40,  dark  chesnut     ....  3  92  3-98 
Man  of     32,  chesnut     ....  4-36  4-37  440 
"        30,  red    8-23  7-77 
Girl  of     20,  very  fair    .       .       .       .     .  4-17  4-22 
Boy  of     18,  red   4-21  4-12 
"         16,  chesnut     .....  4-27  4*31 
"         15,  chesnut     .....  4-09  4-64 
Girl  of     15,  fair           .       .       .       .     „  4  27  4  31 
Boy  of     14,  auburn   4-32  4-40 
"         12,  auburn   4-82  5-00 
"        12,  red           .....  5-72  5-80 
Girl  of     10,  chesnut   4-37  4-28 
Boy  of       9,  red    5-22  5-34 
«  3,  fair    4-25 
Whence  it  may  be  concluded,  that  the  average  proportion  of 
sulphur  contained  in  fresh  hair,  is  about  4*50  per  100. 
This  proportion  has  likewise  been  obtained  with  hair  detached 
from  the  cranium  of  a  Peruvian  buried  more  than  four  centuries, 
and  from  an  individual  of  the  race  of  Titicaca,  of  nearly  1000 
years  ago. 
These  ancient  hairs  had  not  lost  their  hygroscopicity. 
We  sometimes  meet  with,  in  the  soft  parts  of  the  organism, 
masses  of  hair  resulting  from  an  abnormal  development,  and 
which  must  not  be  confounded  with  the  pellets  of  hair  found  in 
