Am.  Jour.  Pharm. ) 
Oct.,  1885.  j 
Alkaloids  of  Coca  Leaves. 
475 
1 : 1 ,600  most  of  the  crystals  resemble  carpet  tacks,  consisting  of  a 
short,  well-formed  prism,  with  a  single  branch  from  the  centre,  joined 
at  an  oblique  angle  and  tapered  to  a  point. 
A  few  crystals,  similar  to  those  just  described,  form  after  some  time 
in  solutions  1 :  3,000. 
Chloride  of  gold  produces  characteristic  crystalline  precijMtates,. 
assuming  peculiarly  beautiful  forms.  In  solutions  containing  one  in 
3,000  an  immediate  precipitate  is  produced,  assuming  forms  resembling; 
those  of  fern-fronds  (Fig.  6),  generally  with  a  stellate  arrangement. 
Fig.  6. — Precipitate  formed  by  auric  chloride  in 
solution,  1  : 3000,  of  cocaine  hj^droclilorate. 
X  75  diameters. 
In  solutions  1 : 12,500  crystals  form  after  some  minutes,  showing  the 
same  fern-frond  patterns,  but  not  generally  the  stellate  arrangement. 
A  solution  was  prepared  of  the  amorphous  cocaine  (cocainoidine)  in 
the  form  of  a  hydrochl orate,  and  a  similar  series  of  experiments  car- 
ried out  with  this,  the  general  conclusion  drawn  from  which  was  that 
the  compounds  of  this  alkaloid  are  very  averse  to  assuming  the  crys- 
talline form.  The  precipitates  produced  by  alkalies  did  not  crystallize 
at  all,  neither  that  by  picric  acid.  In  very  dilute  solutions  (1 : 5,000) 
the  chloride  of  gold  produced  after  some  time  minute  prismatic  crys- 
tals, wholly  unlike  in  general  appearance  the  compound  fern-like  crys- 
tals obtained  when  the  crystallizable  salt  was  employed.  Similarly,, 
in  the  more  dilute  solutions  (1 : 1,000)  chloride  of  platinium  produced  a 
few  rosette-like  crystalline  aggregations,  contrasting  strongly  in 
appearance  with  the  feathery  forms  obtained  from  the  crystallizable 
