278  Methyl  Alcohol  in  Wood  Spirit.  \k™j*Ti,lvt' 
but  not  burning  like  resin  or  dissolving  either  in  spirit  or  water.  A 
specimen  of  the  extract  prepared  from  this  bark  may  be  seen  in  the 
Museum  of  the  Pharmaceutical  Society. 
The  bark  of  another  species  of  Ailantlius,  A.  excelsa,  is  mentioned 
as  being  used  by  the  natives  in  dyspeptic  complaints,  and  esteemed  as 
a  powerful  febrifuge.  This  bark  was  the  subject  of  an  exhaustive 
treatise  by  Mr.  Narayan  Daji,  read  before  the  Grant  College  Medical 
Society  of  Bombay,  in  which  its  properties  were  attributed  to  the 
presence  of  ailanthic  acid.    JPharm.  Jour.  (Lond.)  May  9,  1874. 
DETERMINING  THE  AMOUNT  OF  METHYL  ALCOHOL  IN  COM- 
MERCIAL WOOD  SPIRIT. 
By  G.  Krell. 
The  wood  spirit  of  commerce,  even  when  highly  rectified,  consists 
of  a  mixture  in  varying  proportions  of  different  substances,  some  of 
which  have  not  yet  been  studied.  Methyl  alcohol  is  not  always  the 
chief  constituent,  but  for  technical  purposes  it  is  very  important  to 
know  how  much  it  does  contain.  The  methods  heretofore  in  use,  such 
as  boiling  point,  specific  gravity,  action  toward  sulphuric  acid,  caustic 
soda,  salt  solution,  water  and  so  on,  give  almost  no  idea  of  the  real 
amount  of  methyl  alcohol  in  the  wood  spirit.  This  fact  induced  the 
author  to  institute  some  experiments  for  finding  the  simplest  possible 
method  of  determining  the  amount  of  methyl  alcohol  in  wood  spirit. 
Re  has  arrived  at  the  conclusion  that  the  conversion  of  wood  spirit 
into  methyl  iodide  is  best  adapted  to  give  a  clue  to  the  quantity  of 
methyl  alcohol  in  it. 
By  using  the  biniodide  ef  phosphorus  instead  of  iodine  and  phos- 
phorus in  the  apparatus  below  described,  it  is  easy  to  conduct  each 
single  investigation  always  under  the  same  circumstances.  Although 
the  quantity  of  methyl  iodide  obtained  gives  no  absolute  report  of 
the  quantity  of  alcohol  present,  because  such  reactions  never  go  off 
so  smoothly  as  to  produce  the  theoretical  yield,  yet  this  method  fur- 
nishes the  means  of  accurately  comparing  different  specimens  of  wood 
spirit.  If,  for  example,  pure  absolute  methyl  alcohol  be  subjected  to 
this  treatment,  the  yield  of  methyl  iodide  produced  by  this  may  be 
compared  with  that  obtained  from  the  wood  spirit  to  be  tested,  and 
the  proportions  will  show  how  much  methyl  alcohol  is  in  the  latter. 
