AmMl°yU)r'i9Pih9!rnl'  )  Emetine  Hydrochloride.  279 
litmus.  Emetine  hydrochloride  will  readily  retain  1  per  cent,  or 
more  of  free  hydrochloric  acid  and  not  show  its  presence  by  ap- 
pearance or  odor.  This  excessively  acid  product  will,  of  course,  be 
only  "  slightly  acid  to  litmus."  Actual  titration  of  a  solution  of 
emetine  hydrochloride  with  a  standard  alkali  solution  in  the  pres- 
ence of  methyl  red  as  indicator  and  a  limiting  of  the  free  acid  to  a 
few  tenths  of  a  per  cent.,  calculated  as  absolute  HQ,  are  to  be  pre- 
ferred over  the  present  U.  S.  P.  method  of  simply  testing  a  solution 
with  litmus. 
In  connection  with  the  subject  of  local  irritation  attendant  upon 
injection  of  emetine  hydrochloride  solution,  it  may  be  of  interest  to 
mention  that  experiments  on  human  subjects  indicated  that  less  local 
irritation  was  experienced  when  the  solutions  were  prepared  with 
distilled  water  than  when  prepared  with  normal  saline  solution. 
This  was  ascribed  to  the  fact  that  the  solutions  made  with  distilled 
water  were  more  closely  isotonic  with  the  blood. 
The  Effect  of  Tin  on  Solutions  of  Emetine  Hydrochloride. 
A  specimen  of  emetine  hydrochloride,  answering  all  of  the  U. 
S.  P.  requirements  and  having  an  acidity  to  methyl  red  equivalent 
to  less  than  0.1  per  cent,  absolute  HQ  was  dissolved  in  distilled 
water  to  make  a  2  per  cent,  solution.  Tin  foil,  assaying  99.83  per 
cent,  metallic  tin,  and  containing  traces  of  lead,  iron  and  aluminum 
was  allowed  to  stand  in  contact  with  the  solution  of  emetine  hydro- 
chloride at  room  temperature  for  two  weeks.  At  the  end  of  this 
time  the  solution  contained  a  considerable  quantity  of  a  whitish 
flocculent  precipitate,  the  tin  being  apparently  unaffected.  This 
whitish  flocculent  precipitate  when  centrifuged  out  and  washed  with 
water  was  practically  entirely  soluble  in  ether.  The  ether  solution 
yielded  a  substance  upon  evaporation  which  gave  reactions  for  the 
alkaloid.   A  control  experiment  without  tin  remained  perfectly  clear. 
Another  specimen  of  emetine  hydrochloride,  answering  all  of 
the  U.  S.  P.  requirements  and  having  an  acidity  to  methyl  red  equiv- 
alent to  less  than  0.1  per  cent,  absolute  HC1  was  dissolved  in  dis- 
tilled water  to  make  a  2  per  cent,  solution.  Some  of  the  tin  foil 
used  in  the  previous  experiment  was  placed  in  the  solution  and  the 
solution  was  then  heated  on  a  water  bath  under  a  reflux  condenser 
for  one  day.  A  small  quantity  of  precipitate  like  that  yielded  by 
the  previous  experiment  was  obtained.     The  conclusion  is  that 
