WOOD  SPIRIT  AND  ITS  DETECTION. 
155 
gin,  and  making  out  its  history  to  some  extent,  as  well  as  its 
more  important  chemical  relations.  As  this  is  a  matter  not  es- 
sentially connected  with  the  practical  application  of  the  test,  I 
will  reserve  it  for  the  subject  of  a  future  communication, 
merely  stating  here,  that  acetone  is  principally  concerned  in 
the  production  of  the  reaction  already  described. 
I  will  now  give  the  results  of  some  experiments  with  the 
mercurial  solution  above  referred  to,  which  may  serve  to  illus- 
trate its  more  distinctive  characters  ;  I  will  then  pass  on  to 
the  description  of  a  method  for  the  detection  of  "  methylated 
spirits." 
Experiments  with  Mercurial  Solution — A  portion  of 
the  liquid  was  evaporated  in  vacuo  ;  after  a  few  days,  it  had 
solidified  to  a  firm,  opaque  jelly;  after  a  little  time  longer, 
crystals  commenced  to  sprout  out  from  the  edges,  and  contin- 
ued increasing  daily,  until  what  was  formerly  a  jelly  had  be- 
come covered  with  beautifully  formed  acicular  crystals,  many  of 
the  delicate  reed-like  tufts  reaching  far  above  the  edges  of  the 
capsule,  and  growing  as  it  were,  out  of  a  resinoid  amorphous 
mass.  Analysis  proved  that  these  crystals  consisted  merely  of 
chloride  of  potassium,  the  difference  in  crystalline  form  from 
that  usually  observed  being  due,  as  is  well  known,  to  the  modi- 
fying influence  of  organic  matter.  The  gummy  residue  re- 
maining in  the  capsule  after  separating  the  crystals  was  then 
examined  with  a  microscope,  and  found  to  be  totally  destitute 
of  crystalline  structure,  the  detached  pieces  being  smooth  and 
rounded,  very  brittle,  and  semi  transparent.  When  heated  to  a 
temperature  of  about  450°  F.,  it  swelled  up  considerably,  at 
the  same  time  evolving  a  quantity  of  mercurial  and  empyreu- 
matic  vapor,  and  leaving  a  voluminous  residue  of  carbon. 
When  the  original  solution  was  boiled  violently,  a  white  gelati- 
nous precipitate  was  formed,  readily  soluble  in  dilute  hydro- 
chloric acid,  though  apparently  but  slightly  acted  on  by  the 
dilute  acetic,  nitric,  or  sulphuric  acids. 
Excess  of  acetic  acid  was  now  added  to  another  portion  of 
the  alkaline  solution,  and  the  resulting  precipitate  thoroughly 
washed,  and  then  transferred  to  a  retort ;  some  hydrochloric 
acid  was  now  added,  and  the  mixture  distilled.  The  distillate, 
when  tested  with  chloride  of  mercury  and  potash  in  the  usual 
