192 
Bitter  Aloes. 
Ajco.  Jour.  Pharm. 
April,  1887. 
ever,  on  converting  this  lsevorotatory  mixture  into  the  cadmio-iodide, 
it  was  found  that  after  crystallization,  the  crystallized  salt  yielded  a 
base  which  was  less  lsevorotatory  than  before,  whilst  from  the  mother- 
liquor  a  base  was  obtained,  which  in  a  50  per  cent,  alcoholic  solution 
gave  a  rotation  of  — 3°  30'  in  a  decimetre  tube,  compared  with  3°  10' 
for  conine  under  the  same  conditions. — Jour.  Chem.  Soc,  Feb.  1887, 
160;  Berichte  D.  Ch.  Ges.,  1886,  2578. 
BITTER  ALOES:    A  CONFESSION  OF  BEWILDER- 
MENT.* 
By  J.  F.  Brown. 
Almost  the  first  step  in  an  alphabetical  progress  through  materia 
medica  brings  the  student  face  to  face  with  the  numerous  contradic- 
tions which  cluster  round  the  subject  of  this  paper,  making  it  appear 
almost  an  insoluble  conundrum. 
You  will  be  relieved  to  hear  that  I  shall  pass  by  all  questions  of 
botanical  origin  or  of  chemical  formulae,  and  consider  only  those  others 
which  have  been  suggested  by  a  collation  of  the  statements  ad  rem 
published  in  the  Pharmaceutical  Journal  at  different  times,  and  con- 
tained in  a  few  standard  authorities.  All  these  agree  that  the  drug  is 
the  inspissated  juice  which  has  exuded  or  been  pressed  from  superfi- 
cial vessels  in  the  leaf,  and  that  the  different  varieties  fall  naturally 
into  two  classes,  of  which  Socotrine  and  Barbadoes  are  convenient 
types. 
With  the  single  but  weighty  exception  of  the  late  Peter  Squire,  all 
represent  the  first  class  as  usually  prepared  by  solar  heat,  the  second 
by  artificial  evaporation.  There  is  a  consensus  of  opinion  on  the  soli- 
tary point  that  the  latter  process  is  injurious  to  the  quality  of  the  drug, 
which  is,  however,  unsupported  by  facts.  On  almost  every  other  point 
there  is  an  amusing  see-saw  of  learned  evidence,  worthy  of  the  famous 
trial  at  law  of  the  simple  question — what  is  coal  ? 
Thompson  ascribes  the  superiority  of  Socotrine  aloes  to  the  greater 
proportion  of  extractive  contained  therein.  Squire  gives  the  propor- 
tions of  extract  as  75  percent,  and  50  percent,  for  Barbadoes  and 
Socotrine  respectively. 
Squibb  ascribes  the  more  drastic  nature  of  Barbadoes  to  its  having 
*Read  before  the  Dover  Chemists'  Association.  Reprinted  from  Phar.  Jour, 
and  Tram.,  Feb.  19,  1887, p.  678. 
