AmjJuTj?i8£arra-}  Some  Commercial  A  loins.  37 1 
Sol.  in  Water.  Alcohol.  Ether.  Remarks. 
Fehling's  Handworterbuch  i  —  6cc  i  —  2  (86^  ale)      1  —  8 
1  —  60  cold 
Storer's  Dictionary  1  —  5  boiling       very  soluble  insoluble 
Wohler's  Organic  Chem.  difficultly  cold    difficultly  cold 
Phillips  Mat.  Med.  and  Therap.    sparingly  cold    msol.  cold 
readily,  warm     readily,  warm 
1  —  £00  cold 
Sohns'  Diet.  Act.  Prin.  Plants       1  —  10  boiling     soluble  diff.  soluble 
Ladenburg's  Handworterbuch      difficultly  cold 
easily  hot 
In  the  experiments  upon  commercial  samples  the  solubility  was 
taken  at  25 °  C.  instead  of  150  C,  as  the  latter  temperature  is  seldom 
attainable  for  working  purposes  in  an  ordinary  laboratory. 
The  solubility  in  water  was  ascertained  by  placing  1  gramme  of 
aloin  in  a  stoppered  and  graduated  cylinder  and  adding  the  solvent 
in  small  portions,  agitating  thoroughly  after  each  addition  until  solu- 
tion was  completed.  It  was  observed  that  at  a  low  temperature 
(150  C)  the  aloin  was  only  sparingly  soluble,  but  at  250  C.  it  was 
dissolved  with  a  perceptible  deepening  in  coior  of  the  solution. 
The  solubility  in  ether  was  ascertained  by  placing  1  gramme  of 
aloin  in  a  cylinder  as  before,  adding  30  c.c.  of  ether  and  agitating 
occasionally  for  two  hours,  20  c.c.  of  the  filtered  ether  were  then 
evaporated  to  dryness  in  a  tared  watch  glass,  and  the  solubility  cal- 
culated from  the  weight  of  the  residue. 
The  solubility  in  alcohol  was  taken  in  the  same  manner  as  the 
solubility  in  water.  The  melting  point  was  taken  by  placing  a 
small  quantity  in  a  capillary  tube  and  immersing  the  tube  in  melted 
paraffin  along  with  a  thermometer.  The  lowest  temperature  at 
which  it  became  transparent  in  the  thinnest  part  of  the  tube  was 
observed  as  the  melting  point. 
The  ash  was  calculated  after  incinerating  a  weighed  portion  in  a 
platinum  crucible.  Notes  were  also  made  of  the  general  appearance 
and  microscopical  characteristics  of  the  different  samples  under 
consideration,  and  following  is  the  report  of  their  examination : 
Soluble  in 
Water. 
Solnble  in 
Alcohol. 
Soluble  in 
Ether. 
Degree 
Centigrade. 
Melting 
Point. 
Per  Cent. 
Ash. 
Color. 
Microscopic 
Appearance. 
I 
I-IOO 
1-40 
i-Sco 
900 
0-50 
Dark 
brownish 
yellow. 
Distinct  crystals, 
and  crystal 
masses. 
2 
1-70 
1-30 
1-2500 
1180 
o*34 
Light 
yellow. 
CrystalTine 
p'owder. 
3 
1-80 
1-35 
1-2000 
ii5° 
0-04 
Light 
yellow. 
Same  as 
No.  2. 
4 
i-95 
1-20 
1-1170 
IOO° 
0.60 
Brownish 
yellow. 
Same  as 
No.  1 
