668  Alcohol  in  Volumetric  Analysis.  {^ecimbeSe™' 
tnoment's  reflection  will  show  how  far-reaching  the  results  would  be. 
All  of  our  data  based  on  Koettstorfer's  method  would  need  revision, 
if  accuracy  is  desired.  A  large  majority  of  the  results  obtained  for 
alkaloids  and  alkaloidal  residues  by  means  of  volumetric  methods, 
during  the  last  few  years,  would  be  inaccurate. 
On  looking  over  literature,  somewhat,  it  was  soon  found  that  a 
Mr.  Th.  Salzer1  had  recorded  an  apparent  disturbing  influence  of 
alcohol  on  the  end-reaction  of  litmus.  He  soon  discovered,  how- 
ever, that  the  disturbing  agent  was  not  the  alcohol,  but  an  impurity 
in  the  alcohol.  That  commercial  alcohol  almost  invariably  contains 
impurities  is  not  new.  Toxicologists  have  long  since  demonstrated 
such  to  be  the  case.  The  next  communication  that  appeared  on 
this  subject  was  presented  to  the  American  Pharmaceutical  Associa- 
tion,2 last  August,  by  Prof.  C.  Caspari,  Jr.  Since  this  contribution 
has  been  widely  copied,  especially  in  pharmaceutical  journals,  some 
of  the  results  will  be  reproduced  in  this  paper  for  comparison.  This 
worker  presented  the  results  of  a  goodly  number  of  experiments, 
but  he  neglected  first  of  all  to  investigate  the  purity  of  the  alcohol 
employed.  Prof.  Caspari  says  :  "  The  only  explanation  that  can  be 
offered  for  this  peculiar  behavior  of  alcohol,  is  on  the  basis  of 
Arrhenius'  theory  of  electrolytic  dissociation  as  detailed  in  the 
writings  of  Prof.  Ostwald." 
The  writer,  having  employed  alcohol  largely  in  many  volumetric 
analyses  during  the  past  number  of  years,  especially  with  alkaloids 
and  alkaloidal  residues,  proposed  to  determine  whether  alcohol  did 
materially  influence  volumejtric  work,  and,  if  so,  what  per  cent, 
would  vitiate  such  estimations.  The  commercial  alcohol  employed 
was  carefully  examined  and  found  to  possess  the  following  proper- 
ties: Colorless;  free  from  foreign  odor,  when  diluted  with  one-third 
its  volume  of  distilled  water  and  allowed  to  evaporate  spontaneously 
from  blotting-paper;  specific  gravity  0  8179  at  150  C;  50  c.c.  yielded 
an  unweighable,  slightly  colored  residue;  with  silver  nitrate  the 
alcohol  produced  a  slightly  brownish  tint  on  standing  six  hours, 
showing  that  a  limited  amount  of  organic  impurities,  such  as  amylic 
alcohol,  aldehyde,  etc.,  was  present.  This  product  will  be  desig- 
nated commercial  alcohol  in  this  paper. 
1 1895,  Apotheker  Ztg.,  10,  48. 
2 1896,  Am.  J.  Pharm.,  68,  473. 
