NEW  FEATURES  IN  THE  SUPPLY  OF  PERUVIAN  BARK.  89 
tial  oils  are  of  a  pale-green,  but  indicating  the  presence  of  azu- 
lene ;  but  as  oxidation  proceeds,  the  yellow  resin  generated 
conceals  the  azulene.    We  have — 
A.  Ottoes  which  are  colorless,  containing  neither  azulene  nor 
resin. 
B.  Ottoes  which  are  yellow,  containing  resin  only. 
C.  Ottoes  which  are  blue,  containing  azulene  only. 
D.  Ottoes  which  are  brown-green  and  yellow-green,  contain- 
ing azulene  and  resin  together,  in  proportions  varying  as  opti- 
cally indicated. 
It  is  remarkable  how  little  azulene  gives  color  to  an  oil  that 
contains  no  yellow  resin  :  the  otto  of  chamomile  is  familiarized 
to  us  by  its  blue  color,  but  it  does  not  contain  one  per  cent,  of 
azulene ;  Patchouly  otto,  which  yields  six  per  cent.,  and  worm- 
wood otto,  which  gives  three  per  cent,  of  azulene,  do  not  appear 
at  all  blue,  owing  to  the  presence  of  an  excessive  quantity  of 
yellow  resin. 
At  the  third  fractioning  of  wormwood,  the  yellow  resin  and 
the  azulene  are  in  due  proportions  to  form  a  green  solution,  and 
such  is  probably  the  case  with  other  ottoes  known  for  their 
green  color,  such  as  Caguput,  but  which  I  have  not  yet  ex- 
amined. 
Of  the  chemistry  of  azulene,  and  the  part  it  plays  in  connec- 
tion with  odorous  bodies,  I  hope  soon  to  eliminate  some  fresh 
facts  and  to  place  them  before  the  reader. — London  Fharm. 
Jour.,  Dec,  1863. 
NEW  FEATUKES  IN  THE  SUPPLY  OF  PERUVIAN  BARK. 
By  John  Eliot  Howard,  F.  L.  S. 
A  considerable  quantity  of  medicinal  bark  has  recently  been 
introduced  into  the  London  market,  coming  by  way  of  Para, 
on  the  Amazon.  It  consists  of  flat  and  quill  bark  packed  in 
serons,  and  imitating  to  a  considerable  extent  the  primd  facie 
appearance  of  Calisaya  bark.  It  is  probable  that,  from  this 
cause,  it  has  excited  high  anticipations  on  the  part  of  the  im 
porters,  which  are  scarcely  destined  to  be  realized.  The  ex- 
amination for  alkaloids  shows  the  same  proportion  to  be  con- 
tained in  the  flat  and  in  the  quill  portions  of  the  bark,  evi- 
dently from  the  same  tree ;  the  chief  difference  in  the  chemical 
