ON ALOINE. 
288 
so soluble in either cold water or cold spirits of wine as aloine, 
but dissolves very readily in hot spirits of wine. 
I. 0.421 grm. substance dried in vacuo gave 0.547 carbonic 
acid and 0.103 water. 
0.856 grm. gave 0.848 bromide of silver=42.16 Br. 
II. 0.300 grm. substance gave 0.391 carbonic acid and 
0.078 water. 
0.661 grm. substance gave 0.649 bromide of silver = 
0.2762 Br.= 41.78 per cent. 
Calculated numbers. I. IL 
34 C . 2550.00 35.73 85.43 35.53 
15 H. 187.50 2.62 2.71 2.86 
14 0. 1400.00 19.63 19.70 19.83 
3 Br. 2998.89 42.02 42.16 41.78 
7136.39 100.00 100.00 100.00 
The brom-aloine employed in these analyses was prepared at 
two different times. It is plain, therefore from these results, that 
this bromine compound is aloine, C 34 H 18 0 14) in which 3 equivs. 
of hydrogen are replaced by 3 equivs. of bromine. The for¬ 
mula of brom-aloine, therefore, is C 34 H 1S 0 14 Br 3 . 
When a stream of chlorine gas was sent for a considerable 
time through a cold aqueous solution of aloine, a deep yellow 
precipitate was produced. It contained a great deal of combined 
chlorine ; but., as it could not be made to crystallize, it was not 
subjected to analysis. In the present instance, and in those of 
several other feeble organic principles, such as orcine, chlorine 
appears to act somewhat too strongly, so that the constitution of 
the substance is destroyed, and merely uncrystallizable resins 
are produced. Bromine, on the other hand, is much more gentle 
in its operations, and usually simply replaces a moderate 
amount of the hydrogen in the substance, so that, as in the case 
of orcine and aloine, crystalline compounds are produced. 
It has long been known to medical practitioners, that the 
aqueous extract of aloes is by far the most active preparation 
of that drug. The reason of this is now very plain, as the con¬ 
centrated extract of aloes obtained by exhausting aloes with 
cold water consists chiefly of aloine, by much the larger portion 
of the resin being left undissolved. Mr. Smith informs me, that, 
from a series of pretty extensive trials, from two to four grains of 
aloine have been found more effective than from ten to fifteen 
grains of ordinary aloes, Aloine is, I should think, therefore 
likely ere long to supersede, at least to a considerable extent, 
the administration of crude aloes. 
I endeavoured to obtain aloine by operating considerable 
quantities of Barbadoes, Cape, and Socotrine aloes. These 
were macerated in cold water, and the aqueous solutions ob¬ 
tained were concentrated to the state of thin extracts on the 
