Am*Fe0bU!'i£6arm'}  Materia  Mediea  of  the  Mexican  Pharmacopoeia.  73 
sions  of  children.  The  tubers  of  Cyperus  rotundus  Lin.,  which  is 
known  as  peonia  del  pais,  are  improperly  used  as  a  substitute  for  the 
preceding. 
Picoso,  Croton  adenaster,  Jimenez;  Euphorbiacese ;  in  Queretaro. 
Stem  cylindrical,  stellately  hairy ;  leaves  ovate-lanceolate,  covered  with 
stellate  hairs  principally  upon  the  lower  surface ;  the  margin  with 
numerous  pedicillate  pyriform  yellow  glands ;  stipules  with  like  glands ; 
inflorescence  in  small  monoecious  racemes,  having  the  pistillate  flowers 
at  the  base ;  fruit  spherical,  hairy,  three-celled,  three-seeded,  of  a  burn- 
ing taste.  Laso  de  la  Vega  (Observ.  Med.  iv,  17)  found  in  the  plant 
black  resin  soluble  in  ether,  acid  oleo-resin,  volatile  balsamic  matter, 
tannin,  various  coloring  matters,  extractive  and  salts.  The  plant  is 
used  as  an  antiperiodic,  an  infusion  being  prepared  from  1  or  2  gm.  of 
the  leaves  to  500  gm.  of  water. 
Pipitzahoac,  Trixis  fruticosa,  C.  H.  Schultz,  Tr.  Pipitzahuac,  6r. 
Schaffner;  Composite;  in  Tenango,  the  eastern  mountains  of  the 
Mexican  valley,  &c.  The  rhizome  with  the  roots  is  employed.  Rhi- 
zome horizontal,  tortuous,  covered  with  a  thick  brown  layer;  with 
stem-scars  on  the  upper  side;  rootlets  numerous,  cylindrical,  about  5 
Mm.  (i  inch)  thick,  dark  gray,  longitudinally  wrinkled,  and  near  the 
meditullium  with  a  reddish-yellow  crystalline  powder  of  the  natural 
resin  having  an  acrid  taste.  The  virtues  of  the  drug  are  due  to  this 
resin.  Drastic  purgative;  dose  4  to  8  gm.  (see  also  Amer.  Jour.  Phar. 
1884,  pp.  185,  193).  The  powdered  drug  or  the  acid,  internally  ad- 
ministered, usually  imparts  a  greenish  color  to  the  urine. 
The  Pharmacopoeia  recognizes  also  acidum  pipitzahoicwm,  which  is 
directed  to  be  prepared  from  the  roots  deprived  of  the  rhizome,  which 
are  washed  with  water,  dried,  powdered,  exhausted  with  82  pr.  ct. 
alcohol,  and  the  strong  tincture  precipitated  by  slowly  pouring  it  into 
water.  Thus  prepared  it  is  an  active  drastic  in  doses  of  0*20  or  0'30 
gm.  and  forms  a  crystalline  powder  varying  in  color  between  bright 
canary  yellow  and  deep  reddish;  soluble  in  alcohol,  ether,  chloroform 
and  carbon  bisulphide,  fusible  to  a  reddish-yellow  liquid,  which  gives 
off  yellow  vapors  condensing  partly  as  an  oily  liquid  and  partly  as 
brilliant  yellow  prisms ;  the  vapors  are  inflammable  and  burn  with  a 
bright  and  sooty  flame.  Its  most  characteristic  reaction  is  the  behavior 
with  alkalies:  on  adding  a  drop  of  its  alcoholic  solution  to  water, 
followed  by  a  little  ammonia,  a  violet  color  is  produced.  P.  Anschiitz 
and  F.  Mylius  have  recently  (Berichte,  1885)  shown  that  the  above 
