102 
Methyl  Alcohol. 
( Am.  Jour.  Pharm. 
I     March,  1905. 
In  order  to  separate  the  acetone  completely  the  mixture  is  treated 
with  chloride  of  lime,  whereby  the  acetone  is  converted  into  chloro- 
form. 
The  chief  gaseous  products  of  distillation  are  hydrogen,  methane, 
ethane,  ethylene,  carbon  monoxide  and  carbon  dioxide.  Methyl 
alcohol  has  been  said  to  occur  in  traces  in  the  juice  of  some  plants, 
and  methyl  salicylate  is  a  well-known  natural  product  commonly 
called  oil  of  wintergreen.  Pure  methyl  alcohol  has  a  specific  gravity 
at  zero  of  0.810  and  boils  at  66°  C. 
Owing  to  its  having  almost  the  same  density  as  ethyl  alcohol  it  is 
useless  to  try  to  distinguish  between  these  two  bodies  or  one  of 
them  in  a  mixture  with  the  other  by  specific  gravity  alone.  Al- 
though ethyl  alcohol  boils  at  120  higher  than  methyl,  it  is  very  dif- 
ficult to  completely  separate  them  by  fractional  distillation.  Many 
of  the  methods  of  detecting  methyl  alcohol  in  mixtures,  qualita- 
tively, and  of  estimating  it  quantitatively,  are  very  unsatisfactory  and 
to  a  certain  extent  unreliable.  There  are  one  or  two  methods,  how- 
ever, which  are  reasonably  satisfactory  and  which  are  as  follows  : 
A  simple  color  reaction  for  methyl  alcohol  is  described  in  the 
American  Chemical  Journal,  Vol.  xxi,  1899,  p.  266.  This  test  de- 
pends upon  the  oxidation  of  methyl  alcohol  to  formaldehyde,  and 
the  detection  of  the  presence  o  the  latter  compound  by  the  reaction 
with  resorcin  and  sulphuric  acid.  This  is  a  test  which  can  be  easily 
applied,  and  therefore  I  will  give  it  in  sufficient  detail  for  ordinary 
purposes. 
It  is  best  that  the  solution  to  be  examined  should  be  previously 
distilled,  but  this  is  not  always  necessary.  A  spiral  copper  wire  is 
heated  to  a  bright  red  heat  and  plunged  into  a  small  quantity  of  the 
mixed  alcohols  to  be  examined.  It  is  well,  if  the  solution  is  dilute, 
to  repeat  this  process  several  times.  If  the  alcohol  is  concentrated 
it  should  be  diluted  before  the  application  of  the  test.  One  drop  of 
1  per  cent,  aqueous  solution  of  resorcin  is  added  and  the  mixture 
carefully  poured  into  a  test  tube  containing  a  few  cubic  centimeters 
of  concentrated  sulphuric  acid.  The  presence  of  methyl  alcohol  is 
indicated  by  the  production  of  a  rose-red  zone  at  the  conjunction  of 
the  two  liquids.  Above  this  zone- a  scanty  white  or  pinkish  coagu- 
lum  appears  which  finally  separates  and  rises  in  purplish-red  flecks. 
The  only  compounds  which  give  any  reactions  similar  to  the 
above  described  are  the  tertiary  butyl  alcohols,  dimethyl-ethyl  car- 
