A neutral principle obtained from several varieties of aloes, chiefly
from Barbadoes and Socotrine Aloes.
DERIVATION.--Obtained by pulverizing and macerating aloes in cold water,
and evaporating the resulting solution in vacuo. Aloin crystallizes out
and is dried between folds of bibulous paper. It is purified by repeated
solution in hot water, filtration, recrystallization, and finally by
solution in hot alcohol and crystallization.
PROPERTIES.--A micro-crystalline powder or minute acicular crystals,
lemon yellow or dark yellow in color, possessing a slight odor of aloes
and intensely bitter taste. Soluble in water and alcohol.
DOSE.--Horses and cattle, 2 to 3 dr.; sheep, 20 to 60 gr.; pigs, 10 to
40 gr.; dogs, 11 to 20 gr.; combined with other purgatives.