ADULTERATION  OF  ESSENTIAL  OILS. 
325 
bulb  is  less  active  on  account  of  the  large  amount  of  water  it 
contains,  which  is  driven  off  during  exsiccation.  In  all  these 
cases  of  poisoning,  the  symptoms  before  and  after  death  were 
alike. 
3.  The  dried,  as  well  as  the  fresh  bulb,  dug  in  summer,  is  muck 
less  active  than  the  fall  root. 
4.  The  exsiccation  by  the  heat  of  the  sun  in  the  open  air,  is 
preferable  to  any  other  mode  of  drying,  (slicing  transversely, 
immersing  in  boiling  water,  cutting  out  of  the  new  offset,  &c.) 
5.  Good  bulbs  are  not  injured  by  keeping  for  several  years. 
Of  course,  they  must  have  not  been  eaten  by  insects  or  otherwise 
altered. 
6.  The  symptoms  of  poisoning  by  the  fresh  and  dried  bulbs 
being  alike  with  those  produced  by  colchicine,  this  principle  is  to 
be  regarded  as  the  really  active  principle,  though  up  to  the  pres- 
ent time  it  has  not  been  prepared  yet  from  the  bulb.  Pelletier 
and  Caventou  discovered,  in  1819,  gallate  of  veratria  in  the  cor- 
mus  of  colchicum,  but  Geiger  and  Hesse  showed,  in  1833,  that 
this  must  be  a  mistake,  as  they  had  discovered  in  the  seeds  a 
principle  different  from  veratria  to  which  they  gave  the  name  of 
colchicine. 
As  yet,  there  have  been  no  experiments  made  for  comparing 
the  relative  activity  of  the  bulb  and  seeds.  The  mistake  of  the 
latter  being  stronger  than  the  former  may  have  originated  in 
the  fact  that  most  of  the  poisoning  cases  occur  with  the  seeds 
and  their  preparations,  and  that  the  bulb  varies  in  its  activity 
with  the  state  of  its  maturity  ;  that  during  spring  and  summer, 
according  to  the  author's  former  investigations,  it  contains  the 
active  principle  in  very  small  proportions,  and  consquently  ex- 
hibits little  or  no  toxicating  properties. —  Oester.  Zeitschr.  f.  pract. 
Heilkunde,  1856,  No.  22—24,  and  Buchners  N.  Repert.  1856, 
437-444.  j.  m.  m. 
ON  THE  DETECTION  OF  THE  ADULTERATION  OF  ESSENTIAL 
OILS,  ESPECIALLY  WITH  OIL  OF  TURPENTINE. 
By  G.  S.  Heppe. 
It  is  remarkable  that  well-dried  nitroprusside  of  copper  behaves 
in  a  very  characteristic  manner  towards  oil  of  turpentine  and 
