208 
Use  of  Boric  Acid  as  a  Disinfectant.  {Am-.To::r-  Pharm- 
J  J  ^       April,  1919. 
An  examination  of  this  table  seems  to  indicate  very  little  if  any 
germicidal  action  of  the  boric  acid  even  when  added  to  the  agar  in 
rather  large  amounts.    P.  fluorescens  liquefaciens  seemed  to  be 
TABLE  I. 
Organism. 
Number  of  Cubic  Centimeters  of  Saturated  Solution  Boric  Acid 
Added  to  Each  Tube  of  Agar. 
B.  arborescens  
B.  aerogenes  
B.  capsulatus  
B.  cereus  
B.  cloacce  
B.  colon  
B.  cyanogenus  
B.  dysenteries  
B.  enter itidis  (Gaertner)  . 
B.  fluorescens  liquefaciens 
B.  gasoformans  
B.  granulosum  
B.  of  hog  cholera  
B.  mesentericus  
B.  proteus  vulgaris  
Strep,  by o genes  
B.  paratyphosus  "A" 
B.  paratyphosus  "B" 
B.  typhosus  
B.  pyocyaneus  
+  +    ++  + 
++;++  + 
++ 
++ 
++ 
+ 
++ 
+ 
++ 
+ 
++ 
++ 
++ 
++ 
++ 
++ 
++ 
++ 
++ 
++ 
+ 
+ 
++ 
++ 
++ 
++ 
++ 
++ 
+ 
++ 
+ 
++ 
+ 
+ 
+  i  + 
+  +  i  +  + 
+  i  + 
+  + 
++ 
++ 
+  + 
+ 
+ 
+ 
++ 
+  + 
+ 
+ 
+ 
+ 
+ 
++  + 
+  +  ++ 
+  + 
+  +  +  + 
+  +  +  + 
+  +  + 
+  + 
+  + 
+  I  + 
+ 
+  + 
+  !  - 
+ 
affected  to  the  greater  extent  since  it  did  not  grow  on  agar  slants 
with  over  0.4  Cc.  of  saturated  boric  acid  solution.  A  few  other 
organisms  as  indicated  in  the  table  seemed  to  be  inhibited  when 
quantities  of  saturated  boric  acid  solution  approaching  1  Cc.  were 
used.  It  is  possible  that  a  selective  action  may  be  secured  when 
this  reagent  is  added  to  agar. 
In  order  to  use  a  different  environment  and  a  fluid  medium,  the 
same  experiment  was  repeated  with  Frankel's  solution  which  had 
the  f  ollowing  composition :  5  Gms.  sodium  chloride,  2  Gms,  mono- 
calcium  phosphate,  6  Cc.  ammonium  lactate,  4  Gms.  asparagin,  1 
liter  distilled  water,  20  Cc.  N  sodium  hydroxide.  '  To  5  Cc.  of  this 
solution  were  added  increasing  quantities  of  saturated  boric  acid 
solution  after  which  the  tubes  were  inoculated  with  pure  cutlures 
and  incubated  at  370  C,  using  in  each  case  the  same  amount  of 
inoculum.    The  results  are  shown  in  Table  II. 
From  this  table  it  is  apparent  that  any  inhibitory  power  pos- 
sessed by  boric  acid  is  not  constant.    Little  decrease  in  growth  was 
