EDITORIAL. — PEREIRA's  MATERIA  MEDICA. 
191 
buteven  ihisisby  no  means  probable,"  page  396,  vol.  1.  Again:  <£A  comparison 
of  the  analysis  of  pure  gelatin  with  those  of  the  tissues  yielding  it,  will  show 
us  that  there  is  no  chemical  difference  between  the  two,  or  that  at  most,  they 
only  differ  by  a  few  atoms  of  water.  Hence  it  appears  that  in  the  formation 
of  gelatin,  the  material  of  the  tissues  only  undergoes  a  re-arrangement  of  its 
atoms,  or  a  metamerism,  or  at  most  that  it  only  assimilates  water,  just  as 
occurs  when  starch,  inulin,  and  lichenin,  are  converted  by  prolonged  boiling 
into  dextrin  or  glucose." 
The  extensive  additions  to  the  article  on  cod  liver  oil  are  in  the  main 
transcribed  from  the  author's  paper  in  the  Pharmaceutical  Journal,  detail- 
ing the  analysis  of  De  Jongh,  in  which  gaduin  is  described,  and  glycerin 
given  as  a  constituent.  Dr.  Winckler's  experiments  are  merely  alluded  to 
as  attributing  the  efficacy  of  this  oH  to  the  oxide  of  propyl.  Now  if  Winckler 
is  correct,  no  glycerin  exists  in  cod  liver  oil,  it  being  replaced  by  the  oxide  of 
propyl,  which  distinguishes  this  oil  from  all  other  fixed  oils,  and  we  think 
this  statement  deserved  more  comment  than  it  has  received  from  the  Editors. 
In  the  article  on  Castoreum  the  curious  observation  by  Pereira,  that  water 
distilled  from  castor  contained  hyduret  of  salicyle,  is  noticed.  Its  presence 
is  attributed  to  the  salicin  in  the  poplar  and  willow  barks,  used  by  the 
beaver  as  its  food. 
The  text  concludes  with  a  notice  oiHyrax  capensis,  and  the  excrementi- 
tious  product  which  has  been  called  hyraceum. 
The  inordinate  length  to  which  this  review  has  extended  admonishes  us 
of  the  necessity  of  drawing  it  to  a  close,  yet  we  cannot  injustice  do  so  be- 
fore noticing  the  labors  of  the  American  Editor.  When  the  first  American 
edition  of  Pereira's  Elements  was  to  be  published,  Dr.  Carson  found  the 
English  edition  deficient,  in  the  omission  of  many  important  medical  plants 
peculiar  to  the  United  States,  and  he  introduced  distinct  articles  to  meet  the 
deficiency.  The  principal  of  these  were,  Quercus  tinctoria  and  Alba,  Cheno- 
podiura,  Asclepias  tuberosa,  Apocynum  cannabinum  and  androsaemifolium, 
Cerasus  serotina,  Gillenia  trifoliata,  Sanguinaria  Canadensis,  Magnolia 
glauca,  Liriodendron  tulipifera,  Cimicifuga  racemosa,  Coptis  trifoliata, 
Podophyllum  peltatum,  Juglandis  cinerea,  Geranium  maculatum  and  Cornus 
Florida,  which  are  in  the  present  American  edition.  In  most  instances 
they  are  a  reprint  from  the  previous  edition  except  in  some  of  the  pharma- 
ceutical preparations.  In  the  chemistry  of  Sanguinaria,  Dr.  Carson  makes 
no  allusion  to  the  researches  of  Sheil  and  Reigel  on  aanguinarina, 
(Chem.  Gaz.  vols.  i.  and  iv.)  and  the  analysis  of  Podophyllum  by  J.  R.Lewis, 
(Am.  Jour.  Pharm.  vol.  xix.  p.  165,)  clearly  proving  the  presence  of  an  active 
resin  like  jalapin,  has  been  overlooked.  In  a  few  instances  articles  pre- 
viously noticed  have  been  omitted,  as  Asarum  canadense,  and  the  Aralias. 
We  think  in  a  work  professing  to  be  "  an  encyclopaedia  of  materia  medica" 
that  every  indigenous  drug  at  all  in  esteem  should  have  found  a  place,  how- 
ever short  the  notice.  Among  the  items  either  overlooked  or  intentionally 
excluded,  are  Medulla  Sassafras,  Monarda  punctata  and  its  volatile  oil, 
Aristolochia  reticulata  as  the  source  of  much  of  the  commercial  snake  root, 
Cassia  marilandica,  Rhus  glabrum,  Hydrastis  Canadensis,  etc. 
