Jane 10, 1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
9S9 
warm, place, was found, after about two weeks standing, 
to consist of a soft extractive mass, covered all over the 
surface with small white crystals, very difficult to re¬ 
move, on account of the large amount of black, gummy 
extractive adhering to it. The crystals contained in 
this mass could only be obtained after long and repeated 
treatment with animal charcoal; to remove colouring 
matter and other impurities, it might be purified by 
precipitating the colouring matter by a solution of alum; 
but this mode of proceeding can only be recommended 
when arbutin is the only object in view, otherwise it is 
objectionable, as it complicates the process. A quicker 
way, however, to obtain the crystals, I found to be by 
treating the extractive mixture with a mixture of alco¬ 
hol and ether, in which they readily dissolve, leaving 
behind nearly all the impurities ; as thus obtained, the 
crystals have, in their moist condition, a yellowish 
colour, becoming nearly white when dried; they pos¬ 
sessed the same properties as those obtained previously. 
All the crystals obtained by these different processes 
proved to be arbutin , the discovery of which was first 
announced by Kawalier in 1852. 
A second quantity of leaves was reduced to a coarse 
powder, decocted with water, the decoction strained and 
precipitated with neutral acetate of lead, the precipitated 
lead salt was filtered off and the filtrate was treated with 
basic acetate of lead, until a precipitate was no longer 
produced, this being filtered out. Sulphuretted hydro¬ 
gen gas was passed in the filtrate until all the lead was 
precipitated; the sulphuret of lead was then removed by 
a filter, and the excess of hydrosulphuric acid by heating 
the filtrate; this was evaporated to a soft extract, redis¬ 
solved in water, treated with animal charcoal, then again 
filtered and evaporated, and, while hot, set aside. After 
about twenty-four hours’ standing, the bottom of the vessel 
was covered with bunches of small crystalline needles of 
arbutin ; these were pressed and dried between filtering- 
paper,! and purified by redissolving them in a small 
quantity of boiling water and again allowing the crystals 
to separate; these, when pressed and dried, consisted of 
small prismatic needles having a silvery lustre. This 
second process for obtaining the arbutin is, in the main 
points, the original one of Kawalier, except that lie docs 
not precipitate with basic acetate of lead, which, how¬ 
ever, removes nearly all the gum and colouring matter, 
and thereby facilitates the crystallization to some ex¬ 
tent. 
Arbutin generally crystallizes from ether in prismatic 
needles of considerable size and perfectly colourless, from 
an alcoholic solution in small acicular crystals of a 
white colour, and in small bunches of needles from 
water; it is neutral in its behaviour, very soluble in 
warm or hot water, less in cold water or alcohol, more in 
hot alcohol, very sparingly in ether; a concentrated 
solution of arbutin is precipitated by strong alcohol or 
ether added to it, but the precipitate rapidly disappears 
on shaking. Concentrated sulphuric acid or hydro¬ 
chloric acid, added to the crystals on a small plate, gra¬ 
dually dissolves them without change of colour. With 
nitric acid the crystals first turned black and then slowly 
dissolved, the acid assuming a yellow colour and giving 
off’ fumes of nitrous acid. Arbutin in aqueous solution 
does not affect an alkaline solution of sulphate of copper, 
the salts of lead, acetate and subacetate do not precipi¬ 
tate it, salts of iron have no effect upon it; other re¬ 
agents for organic bodies as tannic and gallic acid, bi¬ 
chloride of mercury, nitrate of silver, iodide of potassium 
and bichloride of platinum were tried without any re¬ 
sults. 
While experimenting with these reagents, I acciden¬ 
tally found a very characteristic and remarkable test for 
arbutin. When a solution of arbutin in water is rendered 
alkaline by ammonia, or any other caustic or carbonated 
alkali, and then phosphomolybdic acid is added, a blue 
colour is produced; in strong solutions the coloration 
is of a deep azure blue, but the bluish hue can be ob¬ 
served even in very dilute solutions. One grain of 
arbutin was distinctly indicated in twenty pints of water 
(1 in 140,000) ; this reaction does not occur with molyb¬ 
date of ammonia, nor does it take place when phosphoric 
or phosphomolybdic acid is acted upon by an alkali 
alone. 
A solution of arbutin may be perfectly colourless but 
still impure; when to an impure solution of arbutin 
ammonia or any caustic or carbonated alkali is added, a 
deeper, sometimes orange, colour is produced, while a 
solution of pure arbutin is not affected in this way. 
[The author next describes the composition and glu- 
coside nature of arbutin and the mode of obtaining hv- 
drokin one, the literature on the subject being reviewed 
and compared with his experiments.] 
E. C. Hughes, in an essay on Uva ursi, published in 
the American Journal of Pharmacy, 1817, describes a 
crystalline principle which he obtained from the leaves 
and to which he gave the name “ Ursin.” This ursin, 
although it has not been noticed in European literature, 
has received some attention, and has generally been re¬ 
garded as a distinct principle in American works. As 
this was obtained before the known existence of arbutin, 
and as its mode of preparation is similar to that of ar¬ 
butin, I was led to suppose that the two might, perhaps, 
be identical; to satisfy myself, I prepared some ursin 
according to Hughes’ method, which consists in macera¬ 
tion and percolation of the leaves with cold water, pre¬ 
cipitating the tannin by a solution of gelatine, filtering and 
evaporating to dryness, treating the remaining extract by 
strong alcohol, the alcoholic solution with animal char¬ 
coal, filtering and evaporating spontaneously. By this 
process an acicular crystalline mass, to which a small 
quantity of resin adhered, was obtained, having nearly 
all the properties of arbutin ; the solution, rendered al¬ 
kaline, produced a blue colour with phosphomolybdic 
acid, and it yielded, when boiled with dilute sulphuric 
acid, the same product of decomposition, hydrokinone, 
besides separating ericolin. 
Hughes states, however, that his ursin was precipi¬ 
tated by carbonate of potash and by the solution of 
subacetate of lead, while it was not affected by the tinc¬ 
ture of chloride of iron ; but as he uses a solution of 
gelatine to precipitate the infusion of the leaves, he only 
gets rid of the tannic acid while the gallic acid remains 
in solution, and is afterwards obtained together with 
the arbutin (his ursin). A solution of this mixture, 
then, of course, precipitates with basic acetate of lead, 
but then it ought to be affected by the salts of iron ; but 
the tincture which he used is a very uncertain test, 
owing to the free acid it contains, which does not indi¬ 
cate small quantities, as in this case, while the solution 
of subacetate of lead precipitates even the smallest trace 
of gallic acid. Carbonate of potash would produce a 
slight change in the colour, but an actual precipitation 
did not take place. The ursin of Hughes must, there¬ 
fore, be considered as an impure arbutin. 
[The author then minutely describes the action of 
nitric acid on arbutin and the production of binitro- 
arbutin, discovered by Strecker; also, the decomposition 
of this compound into sugar and binitro-hydrokinone, 
after which the effect of chlorine upon arbutin is con¬ 
sidered.] 
Arbutin has also been found abundantly in Chimaphila 
umbellata , and it probably exists in a number of erica- 
ceous plants. Its medical properties have never been 
practically applied; it was at one time believed to re¬ 
present the diuretic properties of Uva ursi, and Hughes 
states that one grain of his ursin proved a powerful 
diuretic. The celebrated pharmacologist, Dr. Schroff of 
Vienna, who experimented with pure arbutin, states, 
however, that it possesses no diuretic properties at all: 
he gave it in doses as high as 8 grains, and could not 
detect it in the urine. 
When the mother-liquor from arbutin is heated with 
a dilute acid (sulphuric or muriatic) a resinous body 
