GLYCERIN. 
151 
ble  in  all  proportions  in  water  and  alcohol,  but  not  in  ether  or 
chloroform.  Pure  glycerine  evinces  no  reaction  with  litmus  or 
other  test-agents. 
It  is  perfectly  neutral  and  bland,  and  has  the  capacity  of  dif- 
fusing itself  freely  over  and  through  organic  matter,  incorporating 
itself  between  organic  molecules,  by  which  it  is  absorbed  and 
appropriated.  All  organic  substances,  from  the  hardest  bone  to 
the  finest  connective  tissue,  are  penetrated  by  it,  with  such  dif- 
fusive force  as  to  make  their  minute  structure  astonishingly 
transparent.  The  blood  and  pus  globules,  when  suspended  in 
glycerine,  become  quite  transparent,  and  show  up  their  nuclei 
readily,  their  cell-walls  becoming  more  thin  and  transparent, 
and  finally  dissolved.  Epithelial  structure  is  admirably  delineated 
by  its  agency ;  so  are  the  fasciculi  of  striped  muscular  fibre. 
Thin  sections  of  bone,  soaked  in  it,  reveal  in  admirable  style  its 
corpuscles.  All  organic  substances,  soaked  in  glycerine,  are 
thoroughly  preserved,  both  as  to  form,  integrity,  and  softness. 
Applied  externally  to  burnt  surfaces,  mixed  with  subnit.  bis- 
muth, it  forms  the  very  best  application  I  have  ever  used  for 
children  or  adults.  One  part  starch  (Bermuda  arrowroot  is  best) 
and  five  of  glycerine,  heated  up  to  190°  F.,  being  constantly 
stirred,  makes  the  most  agreeable  basis  by  which  to  apply  nit. 
silver  and  other  salts  to  the  eye,  ear,  and  skin.  When  spread 
over  dried  organic  membrane,  it  diffuses  itself  rapidly  over  it, 
and  is  speedily  absorbed  into  its  intimate  structure.  This  prop- 
erty of  glycerine  depends  doubtless  on  the  affinity  that  it  pos- 
sessses  for  organic  molecules,  penetrating  to  them  and  becoming 
a  nutrient  plasma  to  living  tissue.  When  applied  to  false  mem- 
branes, it  diffuses  itself  between  them  and  the  morphological  tis- 
sue beneath,  causing  their  speedy  detachment. 
Thus  in  diphtheria  I  have  repeatedly  applied  it  with  a  brush, 
either  alone  or  with  tannin  dissolved  in  it,  to  the  false  membranes, 
which  would  be  detached  in  a  few  hours.  So,  also,  in  croup. 
The  surfaces  being  so  modified  as  in  a  great  measure  to  cease  to 
reproduce  them.  Burnt  and  blistered  surfaces  often  produce 
false  membranes,  which  induce  severe  constitutional  symptoms, 
in  consequence  of  the  irritability  of  the  surfaces.  Glycerine 
and  morphia  speedily  remedy  them,  soothing  the  nervous  irrita- 
