344  Nature  and  Structure  of  Cochineal.    ( Am^u^-  £Jgrm- 
enzymes.  Apart  from  the  frequently  observed  occurrence  of  en- 
zymes, or  mixtures  of  such,  which  effect  the  hydrolysis  of  amygda- 
lin,  it  has  been  ascertained  by  Th.  Bokorny  (Chem.  Zeitung.,  1900, 
24,  771)  that  my  rosin  or  a  similar  ferment  is  also  widely  distrib- 
uted, having  been  found  in  plants  of  many  different  families  besides 
the  Crucifercc,  although  the  glucoside  (sinigrin)  which  yields  mus- 
tard oil  has  as  yet  only  been  found  in  the  last-mentioned  family. 
A  milk-clotting  enzyme,  or  phytochymase,  has  also  been  stated  to 
occur  in  various  plants. 
The  confusion  which  is  likely  to  be  produced  in  the  literature 
in  consequence  of  the  recent  statements  published  by  Professor 
Kobert  is  much  to  be  regretted,  especially  as  his  conclusions,  which 
appear  to  have  been  too  hastily  formed,  are  so  obviously  and  demon- 
strably wrong.  It  is  for  this  reason  that  I  have  deemed  it  my  duty 
to  again  place  on  record  the  above-mentioned  facts,  as  also  to  main- 
tain that  the  observations  noted  in  my  previous  publications 
(Pharm.  Rundschau,  1890,  8,  29,  and  Pharm.  Journ.,  1901,  67,  258) 
respecting  both  the  toxic  action  and  enzymic  properties  of  the  pro- 
tein ("  robin  ")  of  Robinia  bark  are  perfectly  correct. 
The  Wellcome  Chemical  Research  Laboratories, 
London,  E.  C. 
THE  NATURE  AND  STRUCTURE  OF  COCHINEAL  * 
By  Henry  Kraemer. 
The  cochineal  insect  is  indigenous  to  Mexico  and  Central 
America  and  in  general  appearance,  resembles  a  wood  louse.  It  is 
usually  found  growing  upon  certain  flat-stemmed  forms  of  the 
Cactus  family,  chiefly  species  of  Nopalea.  The  red  dye  found  in 
the  remains  of  the  female  insect  has  been  long  esteemed  by  the  old 
races  in  these  sub-tropical  countries.  Indeed,  not  only  did  they 
appreciate  its  value,  but  in  order  to  increase  the  supplies,  the  cacti 
with  the  insects  were  successfully  cultivated  many  years  before  even 
Cortez  landed  in  Mexico  in  the  early  part  of  the  sixteenth  century. 
The  real  nature  of  cochineal,  however,  was  not  known  until  some 
time  after  the  introduction  of  the  commercial  article  into  Europe. 
In  1530  Acosta  1  concluded  that  it  was  of  animal  origin.    It  was 
*  Read  at  the  annual  meeting  of   the   Pennsylvania  Pharmaceutical 
Association,  June,  1913. 
