238 
CHLORINATED  LUNAR  CAUSTIC. 
Extractuni  Filicis  maris,    93  parts  by  maceration,    146  parts  by  decoction. 
"        Mezerei,  61       "  "  82        "  " 
In  conclusion,  the  authors  quote  the  interesting  tables  from 
Buchner's  K.epertorium,  1843,  concerning  the  quantities  of  ex- 
tracts yielded  by  alcoholic  tinctures,  and  also  tables  of  solubi- 
lity, volatibility,  and  the  influence  of  heat  on  the  vegetable  alka- 
loids and  their  sulphates. 
CHLORINATED  LUNAR,  CAUSTIC. 
By  J.  Lawrence  Smith,  M.  D. 
Prof.  Chemistry,  Medical  Department  University  of  Louisville. 
About  two  years  ago  my  attention  was  directed  to  the  impor- 
tance of  giving  strength  to  the  fused  nitrate  of  silver,  without 
interfering  materially  with  its  purity.  I  then  satisfied  myself 
of  the  value  of  the  introduction  of  chloride  of  silver  into  lunar 
caustic.  No  practical  developement  was  given  to  this  fact  until 
lunar  caustic  became  an  object  of  manufacture  at  the  Louisville 
Chemical  works  ;  I  then  prepared  some  of  it,  with  a  certain  pro- 
portion of  chloride  of  silver,  in  the  manner  to  be  described,  and 
distributed  it  among  surgeons  and  physicians.  Having  heard 
from  many  of  those  who  have  fairly  tried  it,  I  am  fully  prepared 
to  submit  it  to  the  medical  profession  as  an  improved  form  of 
lunar  caustic  for  many  purposes  ;  and  I  am  still  more  encour- 
aged to  do  this,  from  the  fact  that  Dr.  Ed.  R.  Squibb  has  lately 
submitted  it  to  the  Pharmaceutical  Convention  as  being  of  suffi- 
cient importance  to  be  added  to  the  officinal  pharmaceutical 
preparations  of  silver. 
Those  who  use  lunar  caustic,  know  that  it  is  subject  to  two 
objections;  first,  its  great  friability  (which  is  also  variable,  de- 
pendent upon  the  temperature  of  the  mould  in  which  it  is  cast) ; 
and  secondly,  its  too  great  solubility,  so  that  in  touching  a  moist 
surface,  almost  invariably  more  is  applied  than  is  designed  or 
required. 
Nitrate  of  potash  and  nitrate  of  soda  are  often  fused  with  ni- 
trate of  silver,  but  these  are  objects  of  adulteration,  and  the  use 
of  them  gives  scope  to  an  unlimited  deterioration  of  this  valua- 
ble caustic,  and  therefore  should  be  discountenanced  as  much  as 
