RESEARCHES ON ALOETINE. 545 
the property of being coloured red by nitric acid, attributed 
by Messrs. Smith to aloine. 
Without heat, pure aloetine should colour nitric, sulphuric 
and hydrochloric acids, of a citron yellow. When it is boiled 
for about half an hour, with concentrated nitric acid, we 
obtain a solution which, treated with cold water, deposits 
chrysammic acid, in the form of a greenish yellow powder, 
easily recognisable by the magnificent violet tint which it 
communicates to ammonia. These reactions with cold and 
boiling nitric acid are characteristic. 
After having taken so much trouble to isolate the crystal- 
lizable principle of aloes, I thought I at least should find 
recompense in the energetic action of aloetine on the organism. 
I requested my friend, Dr. Vigla, physician to the Maison de 
Saute, to be kind enough to make some experiments in this 
respect, cautioning him that the new substance should act 
with ten times the energy of ordinary aloes. Here, I was 
completely deceived in my expectation ; the first doses were 
carried timidly to 0*05 grammes, and produced no effect; 
then, successively, 0*25, 0*50, and 1 gramme at a time 
were administered. The observations were to the number of 
twenty-three. 
Of these twenty-three observations, sixteen had a completely 
negative result; in two others, the laxative effect was well 
marked, and, in the remaining five, the therapeutical action 
was very slow, and very doubtful. All these observations 
were made with the greatest care by Dr. Vigla, who devoted 
himself with a good grace, for which I cannot thank him 
sufficiently, to the experiments which I desired to make, and 
varied several times the mode of administering the aloetine. 
This substance was given to the same patients, sometimes 
under the form of pills, sometimes in that of powder, or in 
alcoholic solution ; the results were always identical. In 
glancing over the list, we remark the observation No. 4, in 
which a patient, who was easily influenced by 4 grammes of 
calcined magnesia, w T as insensible to the action of aloetine, 
then submitted to the action of magnesia a second time, he 
was again purged. Observations 8 and 16 are analogous; 
only, instead of magnesia, castor oil, or German brandy, was 
used as a comparative test. I was curious to try on myself a 
a still more decisive experiment. I weighed exactly 2 
grammes of aloetine, and divided it into 2 equal parts : I 
took the first part without subjecting it to any manipulation: 
there was no result. The second gramme was heated to 100° 
C. (212° F.), until it was converted into a small amorphous 
and translucid mass, with no appearance of crystallization. 
xxix. 70 
