74  Value  of  Vegetable  and  Animal  Oils.  {^'"'y^C^IiI''^' 
tore,  one  of  some  interest  and  importance,  and,  upon  examination,  I 
believe  it  to  be  the  sort  of  Chiretta  which,  as  stated  above,  is  called  in 
India  Puharee  (hill)  Chiretta.,  and  which  is  derived  from  Ophelia  angus- 
tifolia.,  Don.  ;  or  if  not  from  this  plant,  most  certainly  from  a  species 
of  Ophelia  very  closely  resembling  it.  Thus,  it  may  be  derived  from 
Ophelia  pulchella.,  Don.  It  is,  therefore,  closely  allied  to  the  true  and 
official  Chiretta,  which  is  obtained  from  Ophelia  chirata.,  Grisebach, 
and  it  possesses  in  some  degree  the  bitter  tonic  properties  of  that  drug. 
It  is  satisfactory  to  know  that  such  is  the  case,  and  that,  therefore,  its 
use  can  lead  to  no  serious  consequences,  but  that  as  it  is  very  inferior 
in  its  bitter  tonic  properties  to  the  genuine  drug,  it  ought  not  to  be  sub- 
stituted for  it.  I  have,  therefore,  deemed  it  advisable  to  describe  it  at 
once. — Phar?n.  Journ.  and  Trans..,  Dec.  19,  1874. 
DETERMINING  THE  VALUE  OF  VEGETABLE  AND  ANIMAL  OILS. 
Nowhere  in  the  domain  of  chemistry  do  we  find  such  a  large  and 
important  series  of  compounds,  so  similar  in  chemical  and  physical  prop- 
erties, and  so  difficult  of  separation  when  mixed,  as  the  fatty  oils. 
Watts  enumerates  forty-nine  vegetable  oils,  eleven  fish  oils,  and  five 
animal  oils,  making  a  total  of  sixty-five  oils,  and  vet  his  list  is  defect- 
ive. Although  possessing  such  a  general  family  resemblance,  they  diffisr 
enough  among  themselves  to  cause  a  considerable  difference  in  price, 
and  hence  cheaper  oils  are  used  to  adulterate  the  more  valuable.  To 
recognize  anv  of  these  oils  when  unmixed  is  not  particularly  difficult, 
but  to  detect  the  presence  of  a  few  per  cent,  of  one  oil  in  a  large  quan- 
titv  of  some  other  oil  is  more  difficult,  and  to  determine  the  kind  and 
quantitv  of  the  adulterating  oil  is  almost  an  impossibility.  Because  of 
the  commercial  value  of  an  accurate  and  reliable  method  of  detecting 
adulteration  in  oils,  much  attention  has  been  paid  to  this  subject,  but 
long  and  patient  researches  have,  as  yet,  been  only  partially  rewarded. 
In  a  communication  to  the  Chemical  Section  of  the  Philosophical 
Society  of  Glasgow,  Mr.  J.  J.  Coleman,  F.  C.  S.,  gives  a  detailed 
account  of  the  principal  methods  now  in  use  for  detecting  adulterations 
in  oils,  a  few  of  which  we  give  below. 
The  late  Prof.  Cah  ert  constructed  a  table  showing  the  result  ob 
tained  by  treating  oils  with  acids  and  alkalies  of  various  strengths. 
Twelve  reagents  were  employed  and  one  hundred  and  eighty  reactions 
and  colors  produced  are  given,  which  he  had  observed  in  experimenting 
