12  ''Proof  Spirif'—What  Is  W         { Vm"ry'!V92o: 
of  "proof  spirit,"  and  a  survey  of  a  number  of  text  and  reference 
books  on  pharmacy  and  the  alhed  sciences  has  disclosed  much  mis- 
information on  the  subject. 
Simon's  "Manual  of  Chemistry,"  nth  edition,  1916,  describes 
"proof  spirit"  of  the  LTnited  States  Custom  House  and  Internal 
Revenue  Service  as  being  identical  with  diluted  alcohol  U.  S.  P. 
Neither  the  diluted  alcohol  of  the  ninth  revision  nor  that  of  any  of  the 
preceding  revisions  which  were  consulted  is  of  "proof  spirit"  strength. 
Wilcox's  "Materia  Medica  and  Therapeutics,"  loth  edition,  and 
Culbreth's  "Materia  Medica  and  Pharmacology,"  6th  edition,  19 17, 
also  err  in  giving  "proof  spirit"  as  a  synonym  for  Alcohol  Dilutum 
U.  S.  P. 
Remington's  "Practice  of  Pharmacy,"  6th  edition;  1917,  is 
authority  for  the  statement  that  "United  States  proof  spirit  differs 
from  diluted  alcohol  and  is  stronger;  it  contains  50  per  cent,  (or, 
more  exactly,  49.5  per  cent.)  by  weight  of  absolute  alcohol."  Surely 
this  misstatement,  in  a  book  which  is  so  widely  read  and  quoted, 
will  be  corrected  in  the  next  edition. 
Sadtler  and  Coblentz,  in  "Pharmaceutical  and  Medical  Chem- 
istry," 4th  edition,  191 8,  have  in  mind  the  British  standard  and  say 
that  "proof  spirit"  has  a  specific  gravity  of  0.9198  at  15.5°  C,  and 
according  to  Fow^nes  contains  49.24  per  cent,  by  weight  of  alcohol." 
In  Leffmann  and  LaWall's  "Organic  Chemistry,"  1904,  "proof 
spirit"  is  defined  as  containing,  by  weight,  "50.8  parts  of  absolute 
alcohol  to  49.2  parts  of  water  and  has  a  specific  gravity  of  0.920." 
This  would  be  correct  for  the  British  standard,  were  it  not  for  the 
fact  that  the  quantities  of  alcohol  and  water  are  transposed. 
|.|  The  most  glaring  misinformation  on  the  subject  is  found  in 
Gould's  "Medical  Dictionary."  The  4th  edition  defines  "proof 
spirit"  as  "any  liquor  containing  at  least  49  per  cent,  of  absolute 
alcohol."  In  the  loth  edition,  19 17,  matters  are  made  worse  by 
definition  under  two  headings: 
"Proof  spirit — Alcohol  containing  42.5  to  49.24  per  cent,  of 
absolute  alcohol, ' '  and 
"Spirit,  proof — Dilute  alcohol  with  40  to  50  per  cent,  of  pure 
alcohol." 
Dorland,  in  his  "American  Pocket  Medical  Dictionary,"  nth 
edition,  1919,  uses  these  two  definitions  verbatim  and  is  thereby 
guilty  of  perpetuating  the  fallacy. 
