September 21,1872.3 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
235 
for this substance may he looked upon as consisting 
mainly of crystallized aloin and the resinoid matter; 
and these two substances may, I think, he regarded as 
the two primary constituents of all the varieties of 
aloes. 
My own experiments have been conducted chiefly with 
the Barbadoes variety, because I have found that practi¬ 
cally that is the best source from which to prepare in 
quantity the crystalline principle which I venture to 
call for the sake of distinction “ Barbaloin.” The process 
I employ for that purpose has been already described. 
.(Year Book of Pharmacy, 1870). 
The researches of Fliickiger, which were communi¬ 
cated last year to the Conference, have shown that the 
-crystalline substance met with in Natal aloes, and pro¬ 
bably also that of the Zanzibar variety, is totally different 
from “ Barbaloin,” which occurs not only in Barbadoes 
hut in Socotrine and Cape aloes. Though the compo¬ 
sition of these crystalline bodies is not representable by 
the same formula, there can, however, be no doubt that 
they are analogous in constitution. 
All the different varieties of aloes then may be repre¬ 
sented as consisting of mixtures in various proportions 
of the following proximate constituents:— 
1 . Aloin and products of its decomposition or change. 
2. Resinoid matter. 
3. Accidental ingredients, e. g ., gum, albumen and 
salts, to which there will be no necessity to allude 
further. 
body. I have submitted nataloin to combustion, and 
obtained numbers which lead to the formula C 25 H 28 O u . 
Theory. Experiments. 
C 25 300 59-52 (I) 59-59 (II) 59-53 
Hjg 28 5-55 6-07 5-86 
O u 176 34-92 - - 
And this formula is supported by the composition of 
the acetyl derivative C 25 H 22 (C 2 H 3 0) c 0 n which I have 
also succeeded in obtaining. 
Theory. Experiments. 
C,- 444 58-73 58-54 
H' 40 5.29 5-38 
0 17 272 - - 
Nataloin is characterised by its crystalline form,_ rec¬ 
tangular plates, by its comparatively limited solubility, 
and by giving with nitric acid a blood-red coloration 
which doe 3 not fade unless heat be applied; also 
by- giving no definite bromo-derivative, and lastly 
by furnishing, under the influence of nitric acid, no 
chrysammic, but only picric in addition to oxalic acid. 
It was formerly stated that aloes contained a glucoside. 
I can only say that my own experiments contradict this. 
This matter was referred to in my former paper. I 
have only now to add that the experiments there de¬ 
scribed of boiling pure aloin with sulphuric acid and 
water, has heen extended to Barbadoes and Cape aloes 
with the same negative result. Sugar could in no case 
be detected in the liquid by the fermentation test. 
Aloin. —The barbaloin, isolated originally by Messrs. 
T. and H. Smith, and examined hy Dr. Stenhouse, pos¬ 
sesses the formula C 34 II.jQOj 4 .H 2 O, but in the water-bath 
loses the molecule of water. It is characterized by its 
comparatively ready solubility in alcohol, from which 
it crystallizes in tufts of y r ellow prisms ; by giving, 
when moistened with strong nitric acid, a transient red 
.colour; by furnishing, with excess of bromine water, a 
yellow precipitate of brom-aloin; and by giving, by 
prolonged digestion with nitric acid, a large quantity of 
chrysammic acid. I have recently found (Journ. Chem. 
Soc. [ 2 ] x. 204) that by acting upon barbaloin with 
chlorine in the presence of concentrated hydrochloric 
.acid, a chloro-derivative may also he obtained, which crys¬ 
tallizes readily in tufts of beautiful prisms. It has the 
formula C 3 4 H 30 Ce 6 O 14 . 6 H 2 O. 
No attempt has been made so far as I am aware to 
explain the constitution of barbaloin. It seems to me, 
however, to possess all the characters of a complex 
phenol. Thus it gives with ferric chloride a dark olive 
coloration ; it furnishes a sulpho-acid, the barium salt of 
which is soluble, though not crystallizable. It also 
gives the chloro- and bromo- substitution derivatives 
just alluded to, and when acted upon by nitric acid it 
yields two nitrated acids, viz., picric and chrysammic 
acids. The latter is evidently a derivative of anthra- 
quinone, inasmuch as it is the sole product of the nitra¬ 
tion of chrysophane from rhubarb, and from that body 
anthracene has been obtained. Hence barbaloin most 
probably contains two groups each containing C 14 and 
one C 6 . 
The action of acetyl chloride has not yet been tried, 
but so soon as the number of hydroxyl groups in barb¬ 
aloin is known it will be possible to write for it a con¬ 
stitutional formula. 
The products of the alteration of barbaloin existing in 
ordinary crude aloes comprise anhydrous, non-crystalline 
aloin and oxidation products. These have already 
been fully described in my former paper. 
Nataloin is obtained from Natal aloes, and was first 
discovered by Professor Fliickiger, and described in his 
paper last year. I have found that when previously 
purified by crystallization from alcohol, it furnishes large 
and distinct crystals by deposition from water; and I ana 
indebted to Mr. F. J. Hanbury, at present studying in 
dhe Laboratory of the Pharmaceutical Society, for valu¬ 
able assistance in preparing beautiful specimens of this 
PART II.—BY WILLIAM A. TILDEN, D.SC. LOND., AND 
edwar® rammell [Bell Scholar). 
Resin of Aloes —When almost any kind of aloes is ex¬ 
hausted by successive treatments with cold water, a curdy 
yellowish-brown substance remains as a residue, which 
is commonly known as resin of aloes. In preparing 
extract of aioes according to the directions of the Phar¬ 
macopoeia, the same substance is deposited in a fused 
state as the solution is allowed to cool. It then has 
the aspect of a soft, dark-brown, elastic, sticky matter, 
which gradually hardens and becomes bx-ittle in the 
course of time. It is obvious from its solubility in 
water that it is not a resin in the usual sense of the 
word, and it will be found in fact that, by repeating 
the action of hot water once or twice, a considerable 
portion of it may be taken up and rendered per¬ 
manently soluble so as to resemble very closely the 
rest of the extract. We have made some experiments 
upon this substance, the material operated upon being 
the “ resinoid ” from a very fine sample of Barbadoes 
aloes and a second specimen from Socotrine aloes, for 
which we are indebted to Mr. T. B. Groves, whose 
valuable experiments on aloes are well known. 
The resin in both cases consisted of the matter w hich 
had been deposited in the course of preparing extractum 
aloes B. P., and which had further been subjected to a 
washing with warm water. 
This resin was exhausted by repeated boiling with 
distilled water, acidified by a few drops of acetic acid; 
the solution was filtered through paper m a funnel 
surrounded by boiling water, and the filtrate which had 
a clear sherry-colour was then acidified more strongly 
by the addition of hydrochloric acid and set aside in a 
covered vessel. In a few hours the resin which had 
been deposited was collected, drained from the mother- 
liquor and washed with cold water. In this way we 
had effected the analysis of the original resin into two 
portions, one of which, A, was soluble in hot water; 
the other, B, insoluble. The latter was much darker in. 
colour than the former. They were, both further puri¬ 
fied by dissolving in rectified spirit, filtering, and 
evaporating to'dryness, a temperature of about 220 T anr. 
being maintained until the substance ceased to lose 
^We^had conceived the idea that the so-called resin of 
aloes was a product of the condensation of the crystal- 
