498 
Estimation  of  Nicotine. 
Am.  Jour.  Pharm. 
Oct.,  1884. 
A.  4*387  residue  of  ethereal  extraction  required  24*3  cc.  of  normal 
HC1,  corresponding  to  3*936  pure  nicotine. 
The  neutralized  solution  was  diluted  to  500  cc.  of  0*787  per  cent, 
nicotine. 
B.  8*793  residue  of  ethereal  extraction  were  dissolved  in  water  to 
measure  250  cc. ;  of  these  20  cc.  required  for  neutralization  3*56  nor- 
mal oxalic  acid. 
a.  80  cc.  required  14*4  cc.  of  normal  HC1 ;  were  diluted  to  250  cc. 
b.  80  cc.  required  14*4  cc.  of  normal  H2S04;  were  diluted  to 
250  cc. 
c.  60  cc.  required  10*8  cc.  of  normal  H2S04 ;  were  also  brought  to 
250  cc. 
According  to  the  quantity  of  H2S04  needed  for  the  neutralization  of 
80  cc.  of  solution  B,  the  8*793  of  ethereal  residue  correspond  to  7*290 
nicotine,  and  B.  a.  contains  2*333  nicotine,  or  0*9332  per  cent. ;  1B.  b. 
contains  2  333  nicotine,  or  0*9332  per  cent. ;  B.  c.  contains  1*749  nico- 
tine, or  0*6996  per  cent. 
The  tests  were  made  with  Mayer's  solution,  which  was  prepared 
from  perfectly  pure  mercuric  chloride  and  potassium  iodide,  so  that 
1  cc.  contained  exactly  0*01354  HgCl2  and  0*0498  KI. 
Taking  the  equivalent  for  nicotine  as  162,  and  supposing  that  the 
precipitate  obtained  was  composed  of  HgI2,C10HuN2(HI)2,  and  has 
therefore  the  molecular  weight  of  872,  it  was  found  that  Dragendorff 
gives  the  amount  of  nicotine  that  is  indicated  by  1  cc.  of  M.  S.  too 
low,  and  that  it  ought  to  be  twice  as  large,  that  is,  instead  of  0*00405, 
it  ought  to  be  0*0081. 
The  writer  was  first  led  to  these  investigations  by  the  statement  of 
Dragendorff,  that  only  one-half  of  M.  S.  used,  was  used  for  the  forma- 
tion of  the  precipitate.  Mr.  Zinnoffsky,  who  made  the  tests,  has  ascer- 
tained the  amount  of  mercury  in  the  precipitate,  judging  by  this  of  the 
composition  of  the  precipitate  ;  but  he  has  not  weighed  (at  least  noth- 
ing is  said  about)  the  precipitate,  and  then  he  has  omitted  to  prove  the 
presence  of  nicotine  in  the  liquid  after  M.  S.  has  ceased  to  give  preci- 
pitate. 
Then,  also,  by  taking  the  composition  of  hydrochloride  of  nicotine 
as  C10HUN2(HC1)2,  another  reason  is  given  for  obtaining  the  coefficient 
of  nicotine  too  small. 
1 10  cc.  were  allowed  to  evaporate  spontaneously  under  a  desicator ;  the 
residue  weighed  0*123. 
0*09332  nicotine  correspond  to  0*1215  sulphate  of  nicotine. 
