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ON  THE  MATERIALS  USED  FOR  CLOTHES. 
with  ether,  resembles  in  all  its  properties  the  Phceoretin  of 
Schlossberger  and  Dapping. 
It  will  be  recollected  that  we  stated  that  the  greater  part  of 
the  deposit  from  the  tincture  of  rhubarb,  when  treated  with  alco- 
hol to  remove  chrysophane,  erythroretin,and  phasoretin,  remained 
undissolved ;  by  digesting  this  residue  with  a  moderately  strong 
solution  of  caustic  potash,  it  dissolved  completely,  giving  a  dark 
brownish-red  solution.  To  the  alkaline  solution  hydrochloric 
acid  was  added ;  this  caused  the  separation  of  a  deep  brown  pre- 
cipitate, which  was  first  washed  with  water,  then  with  alcohol,  to 
remove  a  portion  of  phaeoretin  which  it  still  contained.  After 
drying,  the  precipitate  formed  an  almost  black  resinous  sub- 
stance, nearly  insoluble  in  alcohol,  ether,  chloroform,  and  ben- 
zol ;  but  dissolving  readily  in  the  alkalies.  When  heated  on  a 
platinum  foil,  it  takes  fire  without  melting.  These  properties 
accord  with  those  of  the  Aporetin  of  Schlossberger  and  Dopping. 
These  experiments  tend  to  show  that  the  deposit  which  forms 
in  the  tincture  of  rhubarb  is  composed  chiefly  of  chrysophane. 
erythroretin,  phseoretin,  aporetin ;  the  chief  constituents  being 
the  last  named.  The  chrysophane  amounts  to  about  4  per  cent., 
and  hence  the  rhubarb-tincture  deposit  is  a  valuable  material  for 
its  preparation. — London  Pharm.  Jour.,  May,  1858. 
[To  be  continued.] 
ON  THE  MATERIALS  USED  FOR  CLOTHES. 
By  M.  Coulier. 
The  subject  of  this  work  was  proposed  to  me  M.  Michel  Levy, 
who  has  likewise  aided  me  by  advice  which  has  been  very  valu- 
able to  me. 
In  my  experiments  I  used  exclusively  the  materials  worn  by 
soldiers.  These  materials  are  of  linen,  cotton,  and  variously 
colored  cloth.  I  have  successively  considered  these  fabrics  as 
protective  agents — 1st,  against  cold ;  2nd,  against  heat ;  and 
3rd,  as  bodies  destined  to  absorb  the  products  of  the  cutaneous 
excretions.  With  respect  to  this  last  question,  my  experiments 
have  led  me  to  consider  that  when  water  penetrates  a  fabric  in 
sufficient  quantities,  it  is  divided  into  two  distinct  portions  which 
I  shall  call  hygrometrio  water  and  water  of  interposition.  The 
