^""jJnZy,\9w:}         ''Proof  Spirir— What  Is  It?  U 
though  such  sales  are  made  on  prescriptions.  It  is  probable  that 
many  druggists  have  not  heretofore  kept  such  record  of  the  sales 
of  exempted  preparations  and  proprietaries,  and  they  should  take 
cognizance  of  the  requirement  of  the  law  that  such  should  be  kept 
and  the  intent  to  enforce  same  as  shown  by  the  regulations. 
G.  M.  B. 
"PROOF  SPIRIT"— WHAT  IS  IT? 
By  Rai^ph  R.  Koran,  P.D., 
PHII^ADElvPHIA,  PA. 
The  term  "proof  spirit"  is  one  of  British  origin,  American  adop- 
tion and  universal  confusion.  In  Allen's  "Commercial  Organic 
Analysis,"  4th  edition,  we  are  told  that  "formerly  the  British  Excise 
determined  the  strength  of  spirits  by  pouring  a  certain  amount  on 
gunpowder.  A  light  was  then  applied.  If  the  spirit  was  above  a 
certain  strength  ('proof')  the  gunpowder  ultimately  inflamed,  but 
if  weaker  the  gunpowder  was  too  much  moistened  by  the  water  to 
be  capable  of  explosion,  and  the  sample  was  said  to  be  'under  proof. '  ' ' 
Fortunately,  this  archaic  method  of  approximating  the  alcoholic 
strength  of  spirits  is  no  longer  used,  and  by  Act  of  Parliament, 
"prooj  spirit"  is  now  defined  to  be  a  liquid  of  such  density  that,  at 
51  °  Fahrenheit,  thirteen  (13)  volumes  shall  weigh  the  same  as  twelve 
(12)  volumes  of  water  at  the  same  temperature.  The ''proof  spirit" 
thus  produced  has  a  specific  gravity  of  0.91984  at  60/60°  Fahren- 
heit, and  contains,  according  to  Fownes,  49.24  per  cent,  by  weight 
or  57.06  per  cent,  by  volume  of  alcohol.  ^ 
The  United  States  Internal  Revenue  Department  defines  "proof 
spirit"  as  "that  alcoholic  liquor  which  contains  one-half  its  volume 
of  alcohol  of  a  specific  gravity  of  seven  thousand  nine  hundred  and 
thirty-nine  ten-thousandths  (0.7939)  at  60°  Fahrenheit."  "This 
will  correspond  to  a  specific  gravity  of  about  0.9341  if  water  at  60° 
Fahrenheit  be  taken  as  unity  and  to  a  content  of  42.7  per  cent,  by 
weight  of  absolute  alcohol.  Absolute  alcohol  would  contain  200 
per  cent,  of  'proof  spirit'  according  to  the  United  States  system, 
instead  of  175.25  per  cent,  in  the  English  system." 
This  difference  between  the  British  and  United  States  standards 
has  served  to  bring  about  a  pronounced  confusion  in  the  definition 
