19d 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [September 2,1871. 
•spirit of wine, of which 70 parts dissolve at about 60° F., 
one part of nataloin, or of the above-named mixture of 
ether and spirit, 60 parts; while of methylic alcohol 35 
parts, of acetic ether 50 parts, of ether 1236 parts and of 
absolute alcohol 230 parts, are respectively required for 
dissolving one part of nataloin.* 
NataloYn in small crystals is rather more intensely 
yellow than flowers of sulphur; larger crystals display 
• a somewhat orange tint. Its taste is pure bitter, neither 
-a sweetish nor an acrid after-taste being observable. 
In warm or hot spirit of wine nataloin is scarcely 
more soluble than in cold. By heating the liquid even 
gently, it quickly turns darker, assuming a red colour, 
:so that some decomposition is evident, nor can it be 
wholly avoided by evaporation in vacuo. The best me¬ 
thod of recrystaliizing seems to be that of heating the 
•nataloin with 60 or 70 parts of spirit of wine to 100- 
120° F., and allowing the solution thus obtained to evapo¬ 
rate spontaneously during several weeks; in this way 
may be got crystals of £ to £ a millimetre long. 
The crystallographic features of nataloin are very 
-characteristic. The small, first-deposited crystals as well 
as the larger ones, always consist of extremely thin and 
brittle scales, not resembling the crystals originally 
found in the drug. The most perfectly developed crystals 
of nataloin are square, or at least rectangular scales (A), 
Nataloin. 
9 
A crystallised from absolute alcohol. 
B> C, D, E, F, J trom spirit of wine, slowly grown. 
G, H quickly separated from spirit of wine. 
K from acetic ether. 
Fdward Histed of London who has been occupying 
himself also in the examination of Natal Aloes considers" me- 
ihylic alcohol to be by far the best solvent for nataloin. 
but two of their angles are usually more or less trun¬ 
cated (B). The amount of truncation of the angles is 
usually not the same on both sides (C), and is even some¬ 
times restricted to one only (D). Crystals having all 
their four angles truncated are rarely met with (E), and 
pointed scales like F are still more exceptional. 
Nataloin which has been quickly deposited from a 
warm alcoholic solution shows a predominance of the 
form indicated in fig. G, and sometimes also in fig. H 
! which is striated lengthwise. The latter seems therefore 
to be rather a combined figure than an individual 
1 crystal. 
If the scales II are examined in polarized light, the two 
parts namely a b c and a cl c are sometimes manifestly 
different in the dii'cction of their refracting power,* which 
in nataloin is always very brilliant. Finally there are 
also found irregularly developed crystals (J). 
The crystals of pure nataloin being usually so small, 
their angles can only be measured approximatively by 
means of the micro-goniometer. Some estimations not 
quite satisfactorily ascertained, furnished me 82° for the 
angle a and 139° for angle b. The crystals are easily 
broken according to their longitudinal direction, a c for 
instance in fig. H, yet still mox-e so in a direction parallel 
to their surface. If an alcoholic solution evaporates very 
slowly, tabular crystals of appreciable thickness can be 
obtained, yet in a less pure state. If they happen to be 
a little injured, their longitudinal edges exhibit a distinct 
lamellar structure as shown in fig. K. Crystals of this 
kind are chiefly formed from a solution in acetic ether. 
An alcoholic solution yields mostly regular square 
scales. 
NataloYn gives off no water when exposed over con¬ 
centrated sulphuric acid or when heated to 212° F., in 
cither case even for some days; and this behaviour shows 
: at once that it is not identical with the aloin discovered 
by Messrs. Smith of Edinburgh and examined by Dr. 
Stenhouso. According to this chemist, crystallized aloYn 
parts with 2 - 69 per cent, of water when dried over sul¬ 
phuric acid, and entirely loses its crystalline aspect when 
kept for some days over a waterbath. NataloYn is not 
even altered or its weight diminished if it is heated to 
! 284:° F. Decomposition begins to take place only towards 
j 320° F. when the nataloin turns greyish; the temperature 
named having been maintained for many hours, the loss of 
weight amounted only to 3-8 per cent. At 356° to 37U 
F., nataloin fuses becoming previously of a dark, brown 
red, but it is still partially crystallizable as may bo ascor- 
j tained by treating it with solvents. 
NataloYn is soluble in concentrated sulphuric acid; 
the orange liquid yields a precipitate by addition of a 
small quantity of water, but the dingy colour of the 
nataloin so obtained probably shows that partial altera¬ 
tion has taken place. If the vapour of fuming nitric acid 
is cautiously directed on to a solution of nataloin in sul¬ 
phuric acid, the latter acquires a fine green colour, quickly 
changing to red and blue. This very intense and dis¬ 
tinctive reaction which was first pointed out by Mr. 
Histed, may be illustrated as well by rolling a crystal of 
saltpetre in the sulphuric solution. A small grain of 
chlorate of potassium produces a brilliant green zone, 
almost instantaneously disappearing. Nitrate of bismuth 
gives nearly, the same effect. Bichromate of potassium 
acts in a similar manner as with strychnine only that the 
colour is less pure. Natal aloes being so rich in nataloin, 
itself displays these reactions by which in fact, it may be 
easily distinguished from the aloes of the Cape, Zanzibar 
or Barbados. 
By heating nataloin with nitric acid of about sp. gr. 
1*3, to 140°-160° F., a red solution is obtained which at 
length turns yellowish as the nataloin slowly disappears. 
But I have not been able to discover in this liquid either 
picric or chrysamminic acid, yet the latter according to 
* Ibis however may quite as well be due to the occasional 
superposition of extremely thin scales. 
