69


plaster-of-Paris.  Plasler-of -Paris  splints  may  be  made  by  spreading  plaster-
<of-Paris  cream  between  layers  of  linen,  which  are  molded  to  the  parts  and
allowed  to  harden.
Silicate  of  soda  can  be  bought  as  a  solution,  which  is  sometimes  called
liquid  ^ass.  It  may  be  applied  in  the  same  way  as  plaster,  or  a  few  layers
of  gauze  bandage  may  be  applied  and  painted  with  the  solution,  this  process
being  continued  until  the  desired  thickness  is  obtained.  The  silicate  cast
is  light  and  strong,  but  has  the  disadvantage  of  drying  very  slowly  (twenty-
four  hours);  the  process  may  be  hastened  by  adding  pulverized  chalk  or
cement.
The  starch  bandage  is  used  when  a  very  firm  splint  is  not  required.
The  bandage  is  soaked  in  a  solution  of  starch,  made  with  boiling  water,  and
applied  like  the  plaster  bandage.  It  also  requires  twenty-four  hours  or  more
to  harden.
CHAPTER  VI.
INFLAMMATION.
Inflammation  is  an  expression  of  resentment  on  the  ])art  of  living  tissues
when  subjected  to  injury  or  infection,  and  consists  of  (i)  changes  in  the  blood
vessels,  (2)  the  passage  of  fluids  and  solids  from  the  blood  vessels,  and  (3)
changes  in  the  perivascular  tissues.
