470 
Alkaloids  of  Coca  Leaves, 
{ 
Am.  Jour.  Pharm^ 
Oct.,  1885. 
Cocaine  combines  with  oleic  acid  to  form  a  readily  crystallizable- 
salt,  which  is  much  employed  in  the  form  of  a  solution  in  excess  ot 
oleic  acid  or  in  any  bland  oil.  Where  an  oil  is  used  it  will  be  found 
necessary  to  employ  in  connection  with  it  a  certain  proportion  of  oleic 
acid,  or  crystals  of  the  cocaine  oleate  will  separate  from  the  solution  in. 
cold  weather. 
A  more  desirable  preparation,  perhaps,  is  a  solution  in  a  pure  min- 
eral oil  of  the  alkaloid  itself,  and  altliough  there  still  exists  a  preju- 
dice in  the  minds  of  some  physicians  against  the  use  of  mineral  oils- 
in  liniments,  ointments,  etc.,  experience  seems  to  show  that  this  prepa- 
ration at  least  is  as  active  as  a  solution  of  the  oleate  of  the  same* 
.strength  in  oleic  acid  or  in  a  vegetable  oil. 
Fig.  3  ^4.— Cocaine  alkaloid,  crystals  formed  by 
adding  ammonia  to  aqueous  solution,!  :  1000, 
of  cocaine  muriate.   X  75  diameters. 
B.  Cocaine  muriate  crystals,  commercial. 
X  50  diameters. 
Cocaine  combines  with  boric  acid  to  form  a  crystallizable  salt  rather 
sparingly  soluble  in  water,  which  contains  no  more  than  55  per  cent, 
of  the  alkaloid,  one  molecule  of  base  requiring  apparently  four  of 
boric  acid  for  neutralization. 
There  seems  to  be  no  reason  why  this  salt  should  be  used  in  prefer- 
ence to  the  hydrochlorate  or  hydrobromate,  and  in  fact  it  is  little  em- 
ployed. 
With  sulphuric  acid  cocaine  forms  a  salt  wliich  crystallizes  easily  irt 
short  six-sided  prisms ;  of  the  remaining  salts  the  oxalate  may  be- 
mentioned  as  one  which  crystallizes  easily,  and  which  may  be  obtained 
