AmAp£i;  iP^7arm' }  BiUer  Aloes.  1 95 
This  is  rebutted  by  Dobson  and  Tilden's  published  record  of  fifty 
cases,  principally  adult  males,  in  which  all  three  kinds  were  given  in 
doses  not  exceeding  2  grains,  with  effect  described  as  "  slight  and  very 
uncertain." 
Barbaloin,  especially  with  soap,  appeared  slightly  the  strongest  of 
the  three,  but  nataloin  in  6-grain  doses  failed  to  act  in  some,  in  other 
cases  acted  freely  in  smaller  dose.  The  authors  conclude  that  aloin 
acts  as  well  as  an  equal  dose  of  aloes  and  gripes  less.  By  A.  P.  Brown 
aloin  is  considered  not  more  active  than  an  equal  dose  of  aloes,  and 
the  resin  inert,  while  Proctor's  personal  experience  is  that  aloes,  aloin, 
uncrystallizable  extract  and  insoluble  portion  all  acted  equally 
well. 
That  the  solubility  of  aloin  in  water  should  be  variously  stated  as 
1  in  60,  1  in  90,  and  1  in  500,  and  as  insoluble — freely  soluble — solu- 
ble 1  in  30  of  alcohol — is  only  part  of  the  puzzle. 
It  is  agreed  that  the  resin  is  very  uncertain  when  used  hypoder- 
mically,  but  Tilden  and  Craig  take  diametrically  opposite  views  as  to 
whether  it  is  " changed"  (possibly  dehydrated)  aloin,  or  something 
essentially  different.  The  latter  gave  8  grains  with  good  effect,  but 
12  grains  of  a  sample  specially  prepared  free  from  aloin  by  Messrs. 
Smith  failed  to  operate.  Craig's  own  process  consisted  in  dissolving 
well-washed  resin  in  spirit,  and  precipitating  by  the  addition  of  boil- 
ing water.  Fifteen  per  cent,  of  the  product  was  insoluble  in  spirit, 
and  gave  23  per  cent.,  of  ash.  It  is  known  that  the  insoluble  part  of 
aloes  is  to  some  extent  rendered  soluble  by  prolonged  contact  with  hot 
water,  but  this  experiment  points  to  such  treatment  rendering  that 
insoluble  in  alcohol  which  had  previously  dissolved. 
The  successful  hypodermic  administration  of  aloin  seems  to  render 
needless  the  elaborate  building  up  of  those  composite  pill  structures, 
with  casings  of  various  degrees  of  solubility,  which  were  recently  rec- 
ommended. 
Would  it  be  too  much  to  ask  some  competent  student  of  therapeu- 
tics, if  the  ever-rising  flood  of  novelties  will  permit,  to  try  and  throw 
some  light  upon  the  action  of  this  old  and  familiar  drug.  My  own 
diffident  guess  is  that  when  submitted  to  the  process  of  digestion,  and 
especially  to  the  eminently  solvent  properties  of  the  bile,  the  whole 
of  the  drug,  save  only  the  desert  sand  and  comminuted  monkey  skin 
casually  and  occasionally  accompanying  it,  is  capable  of  producing  its 
well-known  benign  effect. 
