120  Volatile  Oil  of  Monarda  Punctata.  {^"mJ^c^K""" 
.  The  alcoholic  solution  (I)  was  evaporated  to  dryness,  redissolved  in 
water  and  then  gave  the  following  characteristic  reactions  for  acetates  r 
1.  With  AgNOg  a  white  precipitate  formed,  which  changed  not 
until  after  some  time. 
2.  On  heating  the  residue  obtained  by  evaporation  of  a  small 
quantity  of  the  liquid  with  Asfi^  the  odor  of  kakodyl  was  produced. 
3.  With  FejClg  a  dark  red  color  was  produced,  and  on  boiling  a 
brownish  precipitate  formed. 
4.  With  concentrated  H2SO4  and  ethyl  alcohol,  the  odor  of  fruit 
ethers  was  produced,  prominently  that  of  butyric  ether. 
The  residue  (II)  not  soluble  in  alcohol  was  dissolved  in  water  and 
then  gave  the  following  reactions  for  formates  : 
1.  With  AgNOg,  a  white  precipitate  formed,  which  on  lx)iling 
darkened  and  became  black. 
2.  FcgClg  produced  a  dark-red  coloration. 
3.  With  concentrated  H2SO4  and  ethyl  alcohol  the  odor  of  formic 
ether  was  developed. 
4.  HgClg  produced  on  boiling  for  some  time  a  white  precipitate  of 
HggClg,  which  was  blackened  by  NH4OH. 
From  the  above  reactions  the  presence  of  acetic  and  formic  acids 
were  indicated,  but  both  existing  in  small  quantity  ;  also  the  presence 
of  a  small  quantity  of  butyric  acid.  The  oil  itself  having  a  neutral 
reaction,  the  above  acids  exist  probably  as  compound  ethers. 
Summary  of  results. — From  these  investigations  the  following  are 
the  most  important  constituents  of  the  oil : 
I.  A  hydrocarbon,  of  the  formula  CiQHig,  which  has  not  pre- 
viously been  examined.  It  is  Isevogyrate,  and  is  present  to  the 
amount  of  about  50  per  cent. 
II.  Thymol,  C^qHi^O,  present  to  the  extent  of  about  25  per 
cent.,  which  is  dextrogyrate.  This  body  it  seems  is  present  in  the 
freshly  distilled  oil  in  a  condition  which  will  not  crystallize,  even  at  a 
low  temperature ;  but  by  age  gradually  becomes  crystalline  and  sepa- 
rates, without,  as  far  as  appears,  any  change  in  chemical  composition. 
III.  Higher  oxygenated  compounds,  comprising  CjoH^gO,  and 
probably  others.    This  portion  is  also  dextrogyrate. 
IV.  Formic  acid. — 1.  Its  silver  salt  was  reduced  on  boiling  the  so- 
lution. 2.  Its  lead  salt  was  insoluble  in  alcohol,  and  gave  character- 
istic reactions.    3.  The  free  acid  reduced  HgCIg  to  HggClg  on  boiling. 
V.  Acrfic  acid. — 1.  Its  iron  salt  dissolved  in  water  with  bright- 
