784 
Normal  Salt  Solution. 
Am.  Jour.  Pharm. 
Nov.,  1918. 
the  reduction  of  the  freezing  point  as  compared  with  distilled  water, 
the  saline  content  was  then  determined  in  terms  of  sodium  chloride, 
by  .calculation ;  and  a  solution  could  thus  be  prepared  that  was 
in  each  case  isotonic  with  the  blood  (/.  e.,  had  the  same  reduction 
of  the  freezing  point).  From  such  data  as  the  foregoing,  a  number 
of  workers  showed  that  a  0.9  per  cent,  solution  was  safe  and  proper 
to  employ  for  human  beings,  if  a  solution  that  was  desired  to  be 
only  monotonic  was  to  be  employed,  without  considering  the  molecu- 
lar concentration  of  the  liquor  sanguinis.  I  might  state  here  that 
a  0.9  per  cent,  and  not  0.85  per  cent,  sodium  chloride  solution  is  used 
and  recommended  by  numerous  physiologists  and  medical  men  as  the 
normal  physiologic  salt  solution.  A  preparation  of  similar  concen- 
tration as  the  normal  solution  to  be  used  in  Great  Britain  is  quoted 
in  Squires  Companion  to  the  British  Pharmacopoeia  (1916  edition) 
as  possessing  the  same  osmotic  pressure  as  blood  and  said  to  be 
isotonic. 
Solutions  that  possessed  a  higher  saline  concentration  than  the 
foregoing  were  said  to  be  hyperisotonic,  while  those  that  contained 
less  sodium  chloride  than  the  normal  solution  were  said  to  be  hypo 
or  hypisotonic. 
It  is  surprising  that  the  British  Pharmacopoeia  does  not  consider 
officially  this  preparation.  In  the  Deutsches  Arzneibuch  (1910), 
this  solution  (official  as  solutio  natrii  chlorati  physiologica)  is  the 
filtered  and  sterilized  solution  containing  8  Gm.  natrium  chloride 
and  .150  Gm.  of  natrium  carbonate  and  991.85  Gm.  of  water. 
In  the  U.  S.  P.  IX,  liquor  sodii  chloridi  physiologicus  (as  the 
official  latin  name)  instead  of  a  0.9  per  cent,  is  a  .85  per  cent, 
sodium  chloride  solution.  The  formula  calls  for  recently  distilled 
water,  a  great  improvement  over  the  old  products  as  Hort  and  Pea- 
fold  of  the  Lister  Institute  (British  M.  Journal,  No.  2659,  191 1) 
have  shown  that  distilled  water  that  is  allowed  to  stand  in  sealed 
sterile  containers  and  subsequently  used  as  an  infusion  gives  rise  to 
certain  toxic  symptoms  (as  fever,  etc.),  the  cause  of  which  has  not 
been  fully  explained.  Similar  symptoms  are  not  at  all  observed  if 
recently  freshly  distilled  sterile  water  is  employed.  The  pharma- 
copoeia further  recommends  that  the  solution  should  be  sterilized 
preferably  in  the  autoclave  or  by  boiling  for  one  hour  in  a  sterile 
cotton  plugged  container.  The  former  method  is  employed  in  labo- 
ratories where  the  autoclave  is  at  hand,  but  the  average  druggist 
and  practitioner  must  necessarily  use  the  other  method.    It  would 
