358 
DISINFECTING  PROPERTIES  OE  CHARCOAL. 
the  decomposition,  of  any  organic  substances  with  which  it  is  in 
contact.    It  is,  therefore,  the  very  opposite  of  an  antiseptic. 
The  object  of  the  present  paper,  however,  is  chiefly  an  appli- 
cation of  the  absorbent  and  oxidizing  properties  of  charcoal, 
which,  so  far  as  I  am  aware,  has  never  yet  been  proposed,  viz. 
to  employ  a  new  species  of  respirator,  filled  with  powdered  ani- 
mal charcoal,  to  absorb  and  destroy  any  miasmata  or  infectious 
particles  present  in  the  air  in  the  case  of  fever  and  cholera  hos- 
pitals, and  of  districts  infected  by  ague,  yellow  fever,  and  similar 
diseases.    I  have  got  such  a  respirator  made  by  Ferguson  and 
Sons,  Smithfield,  instrument-makers  to  St.  Bartholomew's  Hos- 
pital.   It  fits  closely  to  the  lower  portion  of  the  face,  extending 
from  the  chin  to  within  half  an  inch  of  the  eyes,  and  projects 
about  an  inch  on  either  side  of  the  mouth.    It  therefore  includes 
the  nostrils  as  well  as  the  mouth.    The  frame  of  the  respirator  is 
made  of  thin  sheet  copper,  but  the  edges  are  formed  of  lead,  and 
are  padded  anct  lined  with  velvet,  so  that  it  can  be  made  to  fit 
tightly  to  the  face.    The  powdered  charcoal  is  kept  in  its  place 
by  means  of  two  sheets  of  fine  wire  gauze,  from  a  quarter  to  an 
eighth  of  an  inch  apart.  As  the  body  of  the  apparatus  is  metallic, 
it  has  been  electro-plated  with  silver.    Electro-plating  the  respi- 
rator with  platinum  or  gold  would  certainly  be  an  improvement. 
There  is  a  small  opening  closed  with  a  ivire- gauze  screw,  by  means 
of  which  the  respirator  can  be  filled  with  charcoal  or  emptied  at 
pleasure.    The  respirator  is  kept  in  its  place  by  an  elastic  band 
passing  round  the  back  part  of  the  head.    I  have  employed 
animal  charcoal  as  the  more  porous  substance,  but  I  should  think 
wood-charcoal  would  answer  perfectly  well.*    The  object  in  view 
is,  by  filtering  the  air  through  such  a  porous  substance  as  animal 
charcoal,  to  intercept  the  miasmata  which  may  have  got  mixed 
with  it.    These,  I  think,  cannot  fail  to  be  absorbed  by  the  pores 
of  the  charcoal,  where  they  will  be  rapidly  oxidated  and  destroyed 
by  the  condensed  oxygen  with  which  they  will  be  brought  into 
the  most  intimate  contact.    The  probability  of  this  expectation 
being  realized  is  greatly  strengthened  by  the  results  of  repeated 
trials  with  the  respirators  on  certain  noxious  and  offensive  gases, 
*  Since  the  above  was  written,  I  have  ascertained  by  experiment  that 
common  wood  charcoal  is  even  more  efficacious  than  animal  charcoal. — J.  S. 
