Am'sJe0pUtr'i9i9rm'^  U-  S-  P-  Test  for  Methyl  Alcohol  597 
yellow  to  make  the  final  test  somewhat  obscure.  A  pure  sodium 
sulphite  was  substituted  and  the  following  formula  for  fuchsin- 
sulphurous  acid  T.  S.  was  found  to  be  more  satisfactory.2 
Dissolve  .500  Gm.  f  uchsin  in  300  Mils  warm  water ;  cool  and  add 
1 1.2  Gm.  sodium  sulphite  (90  per  cent.)  dissolved  in  200  Mils  of 
water,  then  add  20  Mils  of  hydrochloric  acid.  The  fuchsin  and  sul- 
phurous acid  are  present  in  the  same  amounts  as  in  the  official  T.  S. 
It  has  been  found  best  to  allow  the  fresh  solution  to  stand  for  a  few 
hours  before  use  as  it  may  be  temporarily  yellow. 
It  is  recommended  that  the  test  be  carried  out  as  follows : 
In  the  first  of  two  test  tubes  place  5  Mils  of  pure  10  per  cent, 
ethyl  alcohol  and  in  the  second  5  Mils  of  the  alcohol  to  be  tested, 
which  has  been  previously  diluted  to  10  per  cent. ;  cool  or  warm 
them,  as  may  be  necessary,  to  25 0  C.  by  immersing  in  water  of  that 
temperature  for  several  minutes.  Add  each  reagent  to  the  contents 
of  both  test  tubes  before  proceeding  further  with  either  one  in  order 
to  have  the  conditions  in  both  as  nearly  alike  as  possible ;  cool  both 
quickly  to  25 0  C.  after  each  addition  of  sulphuric  acid  and  keep 
them  at  that  temperature  throughout  the  test.  If  the  blank  gives  a 
bright  red  color  at  once  which  does  not  fade  in  ten  minutes,  or  if  a 
faint  pink  or  violet  appears  which  does  not  fade  in  ten  minutes, 
repeat  the  test  with  both  and  vary  the  temperature.  If  the  blank  is 
violet  after  ten  minutes  too  high  a  temperature  is  indicated;  if  a 
bright  red  color  persists,  too  low  a  temperature.  It  is  much  more 
simple  and  quick  to  make  a  control  test  as  above  than  to  keep  a  very 
exact  control  of  the  temperature.  In  the  absence  of  methyl  alcohol 
no  pink  or  violet  color  appears  within  half  an  hour  under  artificial 
(yellow)  light,  nor  a  pale  greenish,  blue  or  violet  in  one  hour  by 
daylight,  the  solution  being  pale  yellow  or  colorless.  When  much 
methyl  alcohol  is  present  the  solution  will  become  violet  at  once, 
changing  to  purplish  red. 
Chemical  Laboratory  of  the 
Philadelphia  College  of  Pharmacy, 
June,  1919. 
2  Elias  Elvove,  "  Notes  on  the  Detection  of  Small  Amounts  of  Methyl 
Alcohol,"  Jour,  of  hid.  and  Eng.  Chemistry,  March,  1917,  p.  295. 
