AmAS™/ia^rin'}  Botany  and  Chemistry  of  Essential  Oils.  397 
(1)  Gelsemine  is  a  dry,  non-crystalline  mass,  white  in  color, 
bitter,  strongly  alkaline  and  insoluble  in  water.  Neither  nitric  nor 
sulphuric  acids  give  color  reactions,  but  if  an  oxidizing  agent,  such 
as  manganese  peroxide,  cerium  oxide  or  potassium  dichromate  be 
added  to  a  solution  in  the  latter  liquid,  it  assumes  an  intense  red 
color  which  gradually  becomes  green.  The  gold  and  platinum 
double  salts  are  soluble  in  hot  water,  and  on  cooling  separate  in  a 
crystalline  state.  An  analysis  of  the  hydrochlorate  showed  the 
formula  C49H63N5Ou.2HCl. 
(2)  Gelseminine  is  amorphous,  strongly  alkaline,  insoluble  in  water, 
but  soluble  in  alcohol,  ether  and  chloroform.  The  salts  are 
amorphous,  yellow  and  easily  soluble  in  water.  Sulphuric  acid 
colors  it  yellow;  nitric  acid,  green;  sulphuric  acid  and  oxidizing 
agents,  violet  gradually  becoming  green.  The  platinum  double 
salt  is  amorphous  and  brownish  yellow  in  color  and  easily  soluble  in 
water  and  alcohol.  By  liberating  the  alkaloid  polymerization 
takes  place.    Analysis  showed  the  formula  C42H47N3014HClPtCl4. 
H.  C.  C.  M. 
THE  BOTANY  AND  CHEMISTRY  OF  ESSENTIAL  OILS.1 
By  H.  A.  D.  Jowett. 
v  Botany. — The  essential  oils  or  products  from  which  they  are 
derived  appear  to  be  confined  to  certain  orders,  Rutaceee,  Myrtaceee, 
Umbelliferee,  Composite?,  Labiates,  Lauraceee,  Conifem,  and  others, 
but  though  confined  to  a  relatively  few  natural  orders,  they  are 
found  in  all  parts  of  the  plant,  and  may  occur  in  seeds,  roots,  stem, 
leaves  or  flowers. 
The  oil  is  generally  contained  in  special  receptacles  in  the  plant, 
which  maybe  divided  into  vessels  and  cavities,  and,  indeed,  they  are 
often  classified  under  these  heads,  but  I  prefer  to  treat  of  them  as 
(a)  of  protogenetic  origin,  arising  by  the  differentiation  of  funda- 
mental tissue,  and  of  hysterogenetic  origin,  appearing  in  differen- 
tiated tissue. 
Those  of  protogenetic  origin,  which  are  by  far  the  most  common, 
may  furthermore  be  divided  into  vessels  and  cavities. 
(1)  Vessels. — These  are  generally  of  schizogenous  origin,  and 
occur  in  Coniferee,  Composites  and  Vmbelliferee.    They  are  formed  in 
1  Read  at  a  meeting  of  the  Chemists'  Assistants'  Association,  held  on  Thurs- 
day, March  2,  from  Pharm.  Journ.  Trans.,  July  1,  1893,  p.  6. 
