214  History  of  Soap  in  Pharmacy.  {Am,i°aUyr;i907?rm' 
The  French  codex  as  far  back  as  1748  mentions  a  number  of 
soaps,  viz  : 
Sapo  albus,  ordinary  soap, 
Sapo  variegatus,  and 
Sapo  hispanicus. 
L,ater  on  a  Sapo  albus,  made  of  almond  oil,  is  mentioned. 
In  various  pharmaceutical  works  a  turpentine  soap  is  mentioned 
(about  181 8),  made  of  potassium  carbonate,  oil  of  turpentine,  "and 
rosin  ;  and  Henry  and  Guibert,  in  their  "  Traite  de  Pharmacie,"  in 
18 18,  mention  a  soap  made  of  beef  marrow  and  soda. 
The  German  Pharmacopoeia,  for  more  than  a  century,  speaks  of: 
Sapo  domesticus, 
Sapo  medicatus,  a  white  powder  ; 
Sapo  oleaceous  (Castile  soap), 
Sapo  terebinthinatus,  and 
Sapo  viridis  or  Kalinus. 
The  principal  use  of  all  these  soaps,  however,  as  far  as  medicine 
is  concerned,  was  the  administration  of  various  medicaments  in  pill 
form,  and  soap  was  probably  the  most  favored  excipient  for  making 
pills.  Opium,  squills,  sodium  bicarbonate,  aloes,  myrrh,  iron,  various 
mercury  compounds,  and  others,  were  made  into  pills  by  the  aid  of 
soap,  and  in  the  Pharmacopoeia  of  1830  we  also  find  a  pill  called, 
officially,  Compound  Pill  of  Soap,  and  containing  y2  grain  of  opium 
and  2  grains  of  soap  in  each  pill.  This  is  a  harmless  name  for  so 
powerful  a  pill,  which,  however,  was  dropped  in  1880.  Up  to  this 
time  medicine  had  no  other  use  for  soap  except  as  a  general  hygienic 
agent. 
These  remarks  relate  to  soap  only  in  so  far  as  the  word  is  under- 
stood by  the  layman,  that  is,  a  soluble  compound  of  an  alkali  and  a 
fatty  acid.  Chemically,  however,  we  also  have  insoluble  soap,  that 
is,  salts  of  fatty  acids  with  other  metals,  and  these  salts,  or  at  least 
one  of  them,  have  been  used  in  medicine  for  many  centuries.  This 
is  the  lead  salt  of  oleic  and  palmitic  acids,  generally  called  lead 
plaster.  As  far  back  as  1653,  in  a  book  on  Materia  Medica,  by 
Nicholas  Culpepper,  in  London,  the  author  describes  a  lead  plaster 
under  the  name  of  Diachylon  Simplex.  This  description  begins  as 
follows:  "Let  the  Letharge  boil  with  the  Oyl  of  Olive  and  Hogs 
grease  a  long  time,  continually  stirring  it  with  the  branch  of  a  Palm 
or  other  tree  of  a  binding  nature,  as  Oak,  Box  or  Medlar,  which  is 
