September 2,1871.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
195 
■Stenhouse is formed when aloin and nitric acid are heated 
together. Natalo'in yielded me only oxalic acid. 
I have made five analyses in order to ascertain the 
elementary composition of nataloin. By burning it in a 
-current of oxygen— 
I. 0-2025 gramme yielded 0 43S0 carbonic acid and 
0 1125 water. 
II. 0-2450 gramme yielded 0-5325 carbonic acid and 
0-1372 water. 
III. 0-2288 gramme yielded 0-5135 carbonic acid and 
0"1215 water. 
IV. 0-2605 gramme yielded 0 55 78 carbonic acid and 
0 1395 water. 
V. 0-1598 gramme yielded 0-3525 carbonic acid and 
O’0S98 water. 
These results answer to the following percentages :— 
I. 
ii. 
hi. 
IV. 
V. 
Carbon . 
58-99 
59-14 
61-18 
58-38 
60-15 
Hydrogen 
6-17 
6-24 
5-92 
5 - 9 5 
6-24 
The average numbers of these would be 
Carbon.59-56 
Hydrogen.6-10 
The crystals analysed were taken from different crops 
.and dried at 212° F., except those burnt in analysis V. 
The latter were the purest and largest crystals I have 
-ever obtained; I dried them some days over sulphuric 
.acid, and then exposed them to 212° F. only for a short 
time. The analysis of these crystals appears to me, on 
the whole, to be the most trustworthy; its results would 
dead to the formula C^H^O^, viz :— 
34 C 408 59-47 
38 II 38 5-54 
15 O 240 34-99 
686 100-00 
Both the analysis V., as well as the general average 
agree tolerably well with this formula. Now the same 
.formula is assigned by Stenhouse to his crystallized hy- 
•drated aloi'n. Deprived of the molecule water H 2 0, 
anhydrous amorphous aloin of Stenhouse contains car¬ 
bon 61-07, and hydrogen 5 - 39, with which only my 
analysis III. would agree. There is, however, one fact 
perhaps, which might speak in favour of the higher per¬ 
centage relating to carbon,—that is the composition of 
the drug itself, which I found to be less rich in carbon 
than its crystalline principle. I submitted 0-2645 
gramme of Natal aloes (dried at 212° F.) to elementary 
analysis equally by means of oxygen, and obtained 
0-5365 carbonic acid and 0-1385 water. The drug con¬ 
sequently oontains 54-63 per cent, of carbon and 5-80 of 
.hydrogen. 
Stenhouse in assigning the above formula to crystal¬ 
lized aloin, or rather C 34 H jG 0 14 to the anhydrous aloin, 
was well entitled to do so by the existence of the crystal¬ 
lized bromine compound C 34 H 30 Br f) O 14 , which he dis¬ 
covered. Yet as to the nataloin, I have failed to obtain 
.a well defined bromine compound. If bromine is added 
do nataloin, heat is evolved and bromine evidently ab¬ 
sorbed. The orange mass then proves much more readily 
■soluble in spirit of wine than nataloin, and also in me- 
thylic alcohol; but the solutions yield no crystals, either 
by slow evaporation, or on addition of water. I further 
'enclosed in a sealed tube nataloin with a sufficient 
quantity of bromine and heated the tube for many days 
■ at 212°, but notwithstanding the partial absorption of 
the bromine, this method too proved not more satisfac¬ 
tory. I have, therefore, not further examined the bro¬ 
mine compound. Iodine appears to be incapable of 
.uniting with nataloin. 
Some crystallized compound or well defined product 
of decomposition of nataloin would alone afford the facts 
tor settling its formula. After the unpromising trials 
with bromine and iodine I have attempted to arrive at 
better results by boiling nataloin with dilute sulphuric 
acid. This was done in a tube previously filled with 
common illuminating gas and then sealed in order to 
exclude the influence of air. The liquid nevertheless 
turned dark purplish; it was slowly evaporated after it 
had been saturated with carbonate of barium. A new 
body then made its appearance, consisting of colourless 
very thin feather-like crystals. But this body was al¬ 
ways formed in a very trifling quantity only, so that 
I have not been able as yet to isolate it;* it dissolves 
in methylic alcohol and all the above liquids as well as 
the accompanying products of decomposition. A simi¬ 
larly unpromising result was obtained by gently warm¬ 
ing zinc, dilute acetic acid and nataloin. The latter 
then becomes greenish and is at last dissolved; if the 
zinc is separated by means of sulphuretted hydrogen, 
the liquid, on evaporating, turns likewise purplish, tastes 
no longer bitter, but gives only tx-aces of a crystallized 
body resembling that formed by the action of dilute sul¬ 
phuric acid. 
By a mixture of nitric and sulphuric acids, both con¬ 
centrated, no available compound of nataloin is formed. 
In alkaline liquids natalo'in is also soluble, but very 
quickly darkened; by dry distillation, yellow or bi-own 
oily acid liquids are produced, which are devoid of any 
peculiar aromatic odour. 
The whole of the foregoing facts do not yet allow us 
to foi-rn an idea of the constitution and the true chemical 
nature of nataloin, but they are sufficient to prove that 
it is a new body, certainly differing from the aloin 
hitherto known, although in percentage composition 
there is no considei-able discrepancy between the two 
principles,—probably none at all. 
I have also received from London some aloes which 
I am informed had been imported from Zanzibai-, and 
was offered for sale in 1867. This drug is of a pallid 
reddish-brown hue, and so highly crystalline that it 
might fairly be tei’med crude aloin. Mr. Hanbury is of 
opinion that it is not distinct from the so-called socotrine 
cfloes , but that it is fox-med by the spontaneous drying up 
of the more crystalline portion which settles down when 
fluid socotrine aloes is allowed to repose. He assux-es 
me further that he has noticed that the solid Zanzibar 
aloes which is impoi’ted, though but rai-ely, in skins, is 
pai'tly glossy and transparent, and partly highly crystal¬ 
line. 
Whatever may be the true facts, the crystals of the 
Zanzibar drug are comparatively large prisms such as I 
have never observed in, nor obtained from Natal aloes, 
and the pale, dull liver colour of the latter is extremely 
dissimilar to the reddish hue of the Zanzibar sort. The 
ci-ystals of Zanzibar aloes cannot be so easily isolated as 
nataloin, because their solubility approaches much nearer 
that of the amorphous pai't of the drug. They may, 
however, be obtained by water or dilute alcohol in the 
manner pointed out in the several papers of Stenhouse, 
Smith, and Groves, for the preparation of aloin. Mi-. 
Histed, who has been kind enough to send mo some 
good quantities, obtained his crystals by moistening the 
powdered crude drug with alcohol sp. gr. -960, and 
strongly pressing the pasty mass in sevex-al thicknesses 
of calico;—then dissolving the yellowish ci-ystalline resi¬ 
due in warm, weak alcohol, collecting the crystals which 
form by cooling and repose, and purifying them by re- 
crystalHzation. 
Aloin from Zanzibar aloes is usually less blight in 
tint than nataloin, the crystals being smaller and not 
well developed. The crystallographic chai-acter of 
Zanzibar aloin is different from that of nataloin, the 
former consisting of what I cannot as yet better desig¬ 
nate than as tufted needle-shaped prisms . The best sol¬ 
vent for them appears to be methylic alcohol, fi-om which 
I find that very good crystals, 2 to 3 millimetres long 
* Perhaps one of the products of decomposition of aloes, 
alluded to by liochleder in 1861 and 18o3 ? 
