268  Salicylic  Acid  as  a  Food  Preservative.  {Am'Mayri884aim 
sisted  only  of  the  pure  oil  of  gaultheria.  This  shows  that  the  terpene 
does  not  become  separated  in  the  process  of  distillation. 
The  results  of  these  investigations  may  be  briefly  summarized  as 
follows : 
I.  Oil  of  birch  is  not  identical  with  oil  of  gaultheria,  in  that  it  con- 
sists entirely  of  salicylate  of  methyl,  and  contains  no  terpene. 
II.  Oil  of  gaultheria,  sp.  gr.  1*17,  does  not  contain  ten  per  cent., 
but  only  a  very  small  amount,  of  terpene,  to  the  presence  of  which  is 
due  the  slight  difference  in  odor  and  specific  gravity  between  the  two 
oils. 
SALICYLIC  ACID  AS  A  FOOD  PRESERVATIVE. 
Prof.  Brouardel  has  recently  published  the  conclusions  of  the  Comity 
Consultatifd' Hygiene  Publique  on  this  subject. 
He  observes  that,  although  the  beneficial  operation  of  salicylic  acid 
in  certain  diseases  is  fully  admitted,  the  theory  of  its  action  is  very 
imperfectly  understood.  It  is  known,  however,  that  when  introduced 
into  the  economy  it  is  eliminated  by  the  kidneys  and  liver ;  and  its 
warmest  partisans  admit  that  its  use  is  contraindicated  in  the  subjects 
of  those  diseases,  which  prevent  its  due  elimination,  and  thus  give  rise 
to  an  accumulation  that  in  several  instances  has  proved  fatal.  More- 
over, elimination  is  sometimes  impeded  from  unknown  causes  in  persons 
in  whom  the  functions  of  these  organs  work  healthily ;  while  in  aged 
persons  it  is  alwTays  very  slow.  Under  any  circumstances,  only  a  por- 
tion of  the  salicylic  acid  is  eliminated,  the  remainder  undergoing 
combinations  in  the  tissues,  which,  although  they  may  prove  thera- 
peutically useful,  and  even  for  a  time  produce  no  evil  consequences, 
could  not  be  indefinitely  prolonged  without  mischief  ensuing. 
Even  small  doses  ot  the  salicylate  may  prove  dangerous  to  persons 
who  eliminate  it  imperfectly ;  and  Prof.  Brouardel's  investigations 
during  several  years  past  lead  him  to  believe  that  the  number  of  such 
persons  is  largely  on  the  increase.  Since  1861  he  has  analyzed  the 
urine  of  all  patients  entering  his  hospital  service,  and  his  registers  show 
that  the  frequency  of  albuminuria  has  more  than  doubled  during  the 
last  twenty  years.  Now,  these  patients  are  not  all  condemned  to  an 
early  death,  for  many  recover,  and  others  live  for  many  years ;  and 
when  examples  are  adduced  of  young  and  robust  persons  tolerating 
the  daily  use  of  from  four  to  six  grammes  of  the  solicylates  for  months 
