5 16  Alkaloids  and  Alkaloidal  Drugs.  {^oVember.XT" 
knowing  how  portentous  are  the  demands  now  made,  both  by  legal 
enactments  and  by  commercial  contracts,  upon  the  faithful  services 
of  the  devoted  analyst,  who  is  not  seldom  called  upon  to  do  with- 
out delay  more  than  all  the  world  of  research  has  ever  done  before 
him. 
THE  PERIODIDES  OF  EMETINE.1 
Emetine  seems  to  form  two  periodides,  according  to  whether  the 
iodine  is  added  to  the  alkaloid  or  vice  versa,  but  owing  to  lack  of 
material  we  have  only  isolated  and  analyzed  one,  namely,  the  higher 
periodide.  The  emetine  used  was  obtained  from  Merck  &  Co.  The 
periodide  was  made  by  pouring  200  ex.  of  a  solution  of  emetine  in 
acidulated  water,  this  solution  containing  about  x/2  per  cent,  of  the 
alkaloid,  into  about  500  c.c.  of  a  solution  which  contained  about  I 
per  cent,  of  iodine  with  i-^  per  cent,  of  potassium  iodide,  and  was 
strongly  acidulated  by  hydrochloric  acid.  The  mixture  was  skaken 
till  the  supernatant  liquid  became  perfectly  transparent,  the  precipi- 
tate was  separated  by  means  of  the  pump,  quickly  washed  with  cold 
water  and  then  dried,  first  on  porous  plates  and  then  in  vacuo  over 
sulphuric  acid. 
Thus  obtained,  the  periodide  is  a  dark  brown  powder,  hardly 
soluble  in  benzol,  ether  or  chloroform,  quite  soluble  in  alcohol,  and 
very  soluble  in  a  mixture  of  four  parts  of  alcohol  and  one  of  chloroform. 
The  chloroform  greatly  increases  the  solubility  of  the  periodide  in 
alcohol,  though  chloroform  alone  hardly  dissolves  it.  So  far  we 
have  not  been  able  to  recrystallize  it.  On  evaporation  of  the  sol- 
vent a  viscous  mass  is  generally  left.  Authorities  differ  with  re- 
gard to  the  formula  of  emetine,  as  follows: 
Lefort  and  Wurtz2   .  C28H40N2O5  =  482-98 
Glenard3  .  ..  .  C30H44N2O4  =  494 '96 
Kunz4  C30H40N2O5  =  506-92 
Paul  and  Cownley5   .  CJ5H22N02.=  247-48 
Our  periodide  corresponds  best  to  the  formula  of  Lefort  and 
Wurtz.  Adopting  that,  provisionally,  we  have  an  emetine  hydri- 
odide  heptiodide,  C28H40N2O5.HI.I7. 
:  Included  in  a  paper  published  in  Phar.  Review,  Vol.  17  (1899). 
-  Ann.  Chim.  Phys.  (5),  12,  247. 
a  Ibid.  (5),  8,  233. 
4  Arch.  d.  Pharm.,  225  (1887),  461  ;  232(1894),  466. 
Pharm.  J.  (3),  24,  61. 
