222 
Classification  of  Odoriferous  Principles. 
Am.  Jour.  Pharm. 
May.  1900. 
The  group  of  alcohols  and  esters  includes  the  esters  of  the  lower 
fatty  acids  known  as  "  fruit  essences,"  as  well  as  the  esters  of  the 
unsaturated  alcohols  geraniol  and  linalool,  which  are  so  character- 
istic of  many  of  the  essential  oils. 
The  group  of  ketones  includes  camphor  and  a  number  of  interest- 
ing and  characteristic  principles  of  essential  oils,  including  the  two 
newest,  irone  and  ionone. 
The  group  of  phenols  and  phenol  ethers  includes  the  well-known 
eugenol,  safrol  and  anethol,  besides  thymol  and  others. 
Under  the  group  of  acids  we  have  benzoic  and  cinnamic  acids, 
which  occur  both  free  and  in  ester  combination,  and  under  acid 
anhydrides  we  have  coumarin. 
In  the  group  of  nitrogen-containing  perfumes  we  have  a  variety, 
although  none  of  pre-eminent  value. 
The  last  group,  that  of  hydrocarbons,  of  course  includes  the  ter- 
penes,  which  are  the  basis  of  many  of  the  most  important  essential 
oils. 
The  tables  are  given  below  in  full,  with  names,  constitutional 
formulas,  compounds  and  natural  occurrence. 
CLASSIFICATION  OF  THE  MOST  IMPORTANT  DISTINCTIVE  PERFUMES. 
First  Group  :  Aldehydes. 
Nos.  I  to  2,  unsaturated,  with  open  chains;  No.  3,  closed  chain  ;  Nos.  4  to  11,  closed  chain, 
Benzol  series. 
No, 
Name. 
Citral 
Citronellal 
(Citronellon) 
Furfurol 
Benzaldehyde 
Phenylacetaldehyde 
Cinnamic  aldehyde 
Cumin  aldehyde 
Salicylic  aldehyde 
Anisic  aldehyde  ) 
(Aub£pine)  J 
Vanillin 
Heliotropine  ) 
(Piperonal)  J 
Formula. 
CH 
CH3 
CH3 
CH3 
CH- 
2\ 
C=CH— CH2 
-CH2— C=CH—  CHO 
CH3 
>C=CH — CH2 — CH2 — CH — CH2 — CHO 
I 
CH3 
-CH 
CH       C— CHO 
\o/ 
C6H5— CHO 
C6H5— CH2-CHO 
C6H5— CH=CH— CHO 
C6H4.C3H7.CHO 
C6H4.OH,CHO 
C6H4.OCH3.CHO 
C6H3.OH.OCH3.CHO 
C6H3.OCH2O.CHO 
Natural  Occurrence. 
{Lemon  oil,  lemon 
grass  oil. 
( Citronella  oil,  lem- 
<  on  oil  and  euca- 
(    lyptus  maculata. 
Clove  oil. 
(  Bitter  almond  oil, 
\    cherry  laurel  oil. 
f  Oils  of  cassia  and 
1  cinnamon, 
j  Roman  chamomile 
1  oil. 
(  Oil  of  spiraea  and 
t    crepis  foetida. 
(Vanilla,  benzoin, 
<  Peru  balsam 
(   and  beet  sugar. 
\  Spiraea  oil. 
