GELATINIZATION OF TINCTURE OP KINO. 
259 
ART. XXXVII.— ON THE GEL A.TINIZ ATIO N OF TINCTURE 
OF KINO. By Mr. Redwood. 
The change which takes place in tincture of kino from the 
fluid to the gelatinous form, is a frequent source of inconve- 
nience to the Pharmaceutical Chemist. This change being 
often effected when the tincture has been prepared only a few 
months, and the demand for the preparation being very 
limited, it is found difficult to preserve a supply, at all times 
fit for use. 
No satisfactory explanation appears to have been hitherto 
given, either of the nature or the cause of this change, al- 
though it is alluded to in most Pharmaceutical works. By 
some authors it is said to be peculiar to a particular species of 
kino; and where accounted for at all, it has generally been 
ascribed to the presence of pectin or pectic acid. 
Dr. A. T. Thomson describes four different kinds of kino, 
under the names of African, Botany Bay, Jamaica, and East 
Indian or Amboyna kino. To the second of these, the Bo- 
tany Bay kino, which is the produce of the Eucalyptus re- 
sinifera or iron-bark tree, he ascribes the property of form- 
ing a tincture which gelatinizes on keeping. 
Dr. Pereira also in alluding to this property in tincture of 
kino, says, " where this occurred, probably the Botany Bay 
kino (inspissated juice of the Eucalyptus resinifera) had been 
employed." Pereira further states with regard to this species 
of kino, " that when digested in cold water, it swells, becomes 
soft and gelatinous (like red currant-jelly,) and yields a red 
liquid which reddens litmus, and yields precipitates with 
lime-water, gelatine, acetate of lead, sesqui-chloride of iron, 
and, if caustic potash or ammonia be previously added, with 
the chloride of calcium. Alcohol and emetic tartar occasion 
no precipitate. Digested in rectified spirit, Botany Bay kino 
becomes gelatinous as with water, and yields a similar red so- 
VOL. VIII. — NO. III. 33 
