108 
Hippurate  of  Soda. 
f  Am.  Jour.  Pharm. 
1      Feb.,  1884. 
of  deposit  formed  in  the  above  tinctures,  I  had  the  opportunity  of 
judging  roughly  in  a  few  only,  viz: — Tinct.  cinchonse,  J  oz.  from  1. 
gallon  ;  do.,  3j.  from  1  gallon  ;  tr.  calumbse,  ^iss.  from  1  gallon.  I 
should  be  glad  to  receive  any  deposit,  especially  those  from  the  more 
potent  tinctures,  for  further  examination. — Pliar.  Jour,  and  Trans. y 
Dec.  22,  1883. 
HIPPURATE  OF  SODA. 
By  Peter  Boa. 
Read  at  a  meeting  of  the  North  British  Branch  of  the  Pharmaceutical 
Society,  December  19,  1883. 
At  our  last  meeting  there  was  exhibited  a  specimen  of  hippurate  of 
soda.  This  salt  is  perhaps  deserving  of  more  than  the  incidental 
notice  which  it  then  received,  on  account  of  the  recent  suggestion  of 
Dr.  Garrod  to  employ  the  alkaline  hippurates  in  diseases  arising  from 
excess  of  uric  acid  in  the  system.  In  the  course  of  his  experiments 
he  made  the  observation  that  hippuric  acid,  when  allowed  to  remain  in 
contact  with  uric  acid,  caused  the  disappearance  of  the  latter. 
It  may  be  noted  that  there  are  three  forms  in  which  nitrogenized 
waste  is  eliminated  from  the  system  by  the  kidneys,  viz. :  as  urea,  uric 
acid  and  hippuric  acid.  Of  these  uric  acid  is  the  least  soluble.  It  is 
practically  insoluble  in  water,  and  the  salts  which  it  forms  are  but 
slightly  soluble.  On  account  of  this  characteristic  it  is,  although 
forming  only  a  very  small  part  of  the  excreted  waste,  frequently  the 
cause  of  disease,  owing  to  its  liability  to  form  concretion  in  the  kid- 
neys, giving  rise  to  gravel  and  calculus,  and  in  the  form  of  urate  of 
sodium  it  may  deposit  in  certain  tissues,  and  give  rise  to  gouty  and 
rheumatic  symptoms. 
In  herbivorous  animals  the  renal  excretions  rarely  contain  uric  acid, 
but  hippuric  acid  is  always  present.  Uric  acid  is  probably  formed  at 
one  stage,  but  the  presence  of  hippuric  acid  in  considerable  quantity 
effects  its  decomposition.  Hippuric  acid  forms  salts  which  are  extremely 
soluble. 
To  approximate,  therefore,  the  excretions  from  the  kidneys  of  man 
to  those  of  the  herbivora,  is  to  make  an  important  step  towards  the 
prevention  or  removal,  as  the  case  may  be,  of  the  cause  of  diseases 
which  arise  from  the  defective  elimination  of  uric  acid.  This  may  be 
attained  by  the  employment  of  such  a  salt  as  hippurate  of  soda. 
