172 
Opuntia  Vulgaris,  Mill. 
Am.  Jour.  Ptaarm. 
April,  1896. 
finally  became  pale  yellow.  Professor  Smeltz  attributes  this  fading 
of  the  color  to  a  partial  deterioration  of  the  fruit  during  transporta- 
tion. Another  lot  of  the  undried,  ripened  fruit  was  treated  with 
official  alcohol ;  but  instead  of  allowing  the  red-colored  solution  to 
stand,  the  solvent  was  recovered  by  distillation,  which  left  a  residue 
having  a  bright  red  color.  This  residue  was  soluble  in  water,  but 
insoluble  in  ether.  Sodium  and  ammonium  hydrates,  sodium  carbo- 
nate, hydrochloric  and  nitric  acids,  and  ferric  chloride,  applied  to 
separate  portions  of  the  water  solution,  caused  the  color  to  assume  a 
purplish  shade.  In  the  cases  of  nitric  acid  and  ferric  chloride  this 
new  color  rapidly  faded.  Attention  may  again  be  directed  to  the 
fact  that  the  cochineal  insect  feeds  upon  Opuntia  vulgaris,  and,  con- 
sidering this  in  connection  with  the  above  properties  of  the  coloring 
matter,  it  seems  at  least  barely  possible  that  some  relation  may 
exist  between  this  coloring  matter  and  carminic  acid.  The  author 
regrets  that  the  time  at  her  disposal  was  so  limited  as  to  preclude 
the  investigation  of  this  point. 
For  the  purpose  of  investigating  the  proximate  constituents  of 
the  fruit  of  Opuntia  vulgaris,  a  supply  was  obtained  from  St.  Peters- 
burg, Fla.  The  material  was  collected  from  wild  plants.  When 
received  the  fruit  was  fully  ripened  and  was  still  attached  to  the 
stem.  Work  was  at  once  begun  upon  both  parts.  The  seeds  were 
not  removed  from  the  fleshy  part  of  the  fruit,  but  the  latter  taken 
in  its  entirety. 
Proximate  Analysis  of  the  Fruit. — A  quantity  of  the  fruit  was 
desiccated  until  sufficiently  dry  to  admit  being  reduced  to  a  No. 
60  powder,  into  which  state  the  fruit  was  brought  before  it  was 
employed  in  this  analysis.  To  estimate  the  moisture*  that  yet 
remained  in  the  powdered  fruit,  a  weighed  quantity  was  dried  in  an 
air  bath  to  a  constant  weight  at  a  temperature  of  1  io°  C.  The  loss 
was  considered  to  be  moisture ;  it  amounted  to  1008  per  cent,  of 
the  original  weight  taken.  The  dry  residue  from  the  above  esti- 
mation of  moisture  was  incinerated  until  all  free  carbon  was  con- 
sumed. The  non-volatile  residue  of  the  inorganic  constituents — or 
ash  of  the  fruit — was  found  to  equal  9  26  per  cent.  A  qualitative 
analysis  of  this  ash  revealed  the  presence  of  potassium,  calcium 
and  magnesium  in  the  forms  of  chlorides,  sulphates,  carbonates  and 
phosphates. 
Another  weighed  portion  of  the  powdered  fruit  was  treated  with 
