DOUBLE  SALTS  OF  CARBOLIC  ACID. 
445 
of  minute  organized  germs  upon  the  body.     In  the  ease  of 
vaccinia  they  seem  to  be  demonstrable  as  minute  granules.  By 
inference,  if  not  by  observation,  much  can  be  learned  concern- 
ing the  physical  qualities  of  these  disease-producing  organisms. 
They  are  capable  of  destruction  by  various  chemical  agencies; 
on  this  circumstance  is  based  the  theory  and  practice  of  disin- 
fection.   The  agencies  which  destroy  them  are,  however,  not 
always  chemical ;  some  bodies  which  can  be  proved  to  have  no 
chemical  influence  whatever  have  the  peculiar  property  of  ar- 
resting the  vitality  of  organized  bodies.    Though  means  have 
been  long  adopted,  in  order  to  prevent  the  spread  of  disease,  to 
neutralize  disease-producing  agencies  externally  to  the  living 
body,  it  is  only  lately  that  a  plan  of  treatment  has  been  pursued 
with  the  object  of  killing  the  vitally  endowed  disease-producing 
particles  when  once  they  have  entered  the  living  organism.  The 
plan  of  treatment  by  the  sulphites  recommended  by  Professor 
Polli  no  doubt  destroys  germs,  sulphurous  acid  and  the  sulphites 
acting  upon  them  not  as  chemical,  but  as  vital  poisons.  Per- 
haps the  most  powerful  agent  known  possessing  a  like  property 
is  carbolic  acid.    This,  however,  in  regard  to  its  administration, 
presents  many  practical  difficulties.    The  difficulties  have  been 
overcome  by  the  discovery  and  employment  of  salts  obtained  by 
the  neutralization  of  sulpho-carbolic  acid  (CgllgSO^)  with  the 
alkaline,  earthy,  and  metallic  bases.    The  first  compound  salt, 
sulpho-carbolate  of  potash,  was  obtained  by  Mr.  Crookes,  F.  R.  S. 
The  author  has  succeeded  in  producing,  in  addition,  the  fol- 
lowing salts,  all  having  the  characters  of  true  double  salts,  and 
possessing  brilliant  and  decidedly  crystalline  form :  sulpho-car- 
bolate of  sodium,  of  potassium,  of  ammonium,  of  magnesium, 
of  zinc,  of  copper,  and  of  iron.    An  inquiry  instituted  with  the 
view  of  determining  the  relative  efficiency  of  the  various  salts  in 
staying  fermentative  action  established  the  following  results  : — 
1,  the  sodium  salt;  2,  magnesium  ;  3,  potassium;  4,  ammonium. 
It  was  shown  from  experiments  upon  the  lower  animals,  as  well 
as  from  the  results  of  administration  to  the  human  subject,  that 
the  following  was  an  outline  of  the  plan  of  action  of  the  sulpho- 
carbolates.    They  are  absorbed  with  great  rapidity,  exert  no 
toxic  effect  (the  human  subject  readily  taking  drachm  doses 
