540 
'When great quantities of quartz are conti- 
nually agitated by the sea or river water, 
thes are sometimes reduced to such ven 
minute parts as to be easily carried away, 
suspended in the water; and there are sands 
of so minute a size as to measure less than 
the two or three hundredth part of an inch. 
These are called quick-sands. Immense 
tracts of land consist only of loose sands, par- 
ticularly along the sea-shore in many parts of 
Europe. When sand is about as big as peas, 
it is called gravel ; and when it is free from 
saline and heterogeneous particles, it is em- 
ployed in making mortar, and for other eco- 
nomical purposes. That which is very pure 
serves for making flint-glass, with red calces 
of lead, and the proper alkaline flux; but 
when mixed with ferruginous-black sand, the 
glass assumes a greenish-black colour. “ This 
(savs M. Magellen) l have seen among the 
various specimens of glass made by Mr. E. 
Delaval, F. R. S. who produced a very line 
transparent and colourless glass out of the 
same sand with which he had made some of 
that black glass, and this only by separating 
from it all the ferruginous mixture.” 
QUASSIA, a genus of the monogynia or- 
der, in the decaudria class of plants, and in 
the 'natural method ranking under the 1 4th 
order, gruinales. The calyx is pentaphvl- 
Jous; there are live petals; the nectarium is 
pentaphyllous; there are from two to live 
seed-cases, standing asunder, and monsper- 
moiis. There are three species, the umara, 
simaruba, and excelsa. 
1 . The quassia amara grows to the height 
of several feet, and sends off many strong 
branches. The wood is of a white colour and 
light ; the bark is thin and grey; the leaves are 
placed alternately on the branches, and con- 
sist of two pair of opposite pinna', with an 
odd one at the end : the flowers are all her- 
maphrodite, of a bright red colour, and ter- 
minate the brandies in long spikes. It is a 
native of South America, particularly of Su- 
rinam, and also of some of the West Indian 
islands. The root, bark, and wood, of this 
tree have all places in the materia medica. 
The' wood is most generally used, and is said 
to be a tonic, stomachic, antiseptic, and fe- 
brifuge. 
2 . The quassia simaruba is common in all 
the woody lands in Jamaica. It grows to a 
great height and considerable thickness. T he 
trunks of the old trees are black and a little 
furrowed. Those of the young trees are 
smooth and grey, with here and there a broad 
•yellow spot. The inside bark of the trunk 
and branches is white, fibrous, and tough. It 
tastes slightly bitter. The wood is hard, and 
useful for buildings. It splits freely, and makes 
excellent staves for. sugar-hogsheads. It has 
no sensible bitter taste. The branches are 
alternate and spreading, The leaves are nu- 
merous and alternate. The flowers are of a 
yellow colour, and placed on spikes beauti- 
fully branched. 
The fruit is of that kind called a drupa, and 
is ripe towards the end of May. It is of an 
oval shape, is black, smooth, and shining. 
Hu* pulp is fleshy and soft ; the taste nau- 
seous and sweet. ‘ The nut is flattened, and 
on one side winged. The kernel is small, flat, 
and tastes sweet. The natural number of 
these drupa' is five on each common recep- 
tacle ; but for the most part there are only 
QUASSIA, 
two or three. The roots are thick, and run 
at a small depth under the surface of the 
ground to a considerable distance. The bark 
is rough, scaly, and waited. The inside 
when fresh is a full yellow, but when dry 
paler. It lias but little smell. The taste is 
bitter, but not very disagreeable. This is 
the true cortex simaruba; of the shops. T lie 
shops are supplied with this bark from Gui- 
ana ; but now we may have it from our own 
islands at a moderate expence. 
Most authors who have written on the 
simaruba agree, that in fluxes it restores the 
lost tone of the intestines, allays their spas- 
modic motion, promotes the secretions by 
urine and perspiration, removes that lowness 
of spirits attending dysenteries, and disposes 
the patient to sleep ; the gripes and tenesmus 
are taken off, and the stools changed to their 
natural colour and consistence. In a mode- 
rate dose it occasions no disturbance or unea- 
siness; but in a large dose it produces sick- 
ness at stomach and vomiting. Negroes are 
less affected by it than white people. Dr. 
Cullen, however, says, “ We can perceive 
nothing in this bark but that of a simple bit- 
ter; the virtues ascribed to it in dysentery 
have not been confirmed by my experience, 
or that of the practitioners in this country; 
and leaving what others are said to have ex- 
perienced to be further examined and consi- 
dered by practitioners, 1 can only at present 
say, that my account of the effect of bitters 
| will perhaps explain the virtues ascribed to 
simaruba. In dysentery I have found an in- 
fusion of camomile-flowers a more useful 
remedy. 
3. The quassia excelsa, or polvgama, was 
named by sir Joseph Banks, Dr. Solander, 
and Dr. Wright. It is very common in the 
woodlands of Jamaica, is beautiful, tall, and 
stately, some being 100 feet long, and 10 feet 
in circumference eight feet above the ground. 
The trunk is straight, smooth, and tapering, 
sending off its branches towards the top. 
The outside bark is pretty smooth, of a light 
grey or ash-colour, from various lichens. 
The bark of the roots is of a yellow cast, 
somewhat like the cortex simaruba. r l lie 
wool is of a yellow colour, tough, but not 
very hard. It takes a good polish, and is 
used as flooring. The flowers are small, of 
a yellowish- green colour, with a very small 
calyx’. The male or barren tree has flowers 
nearly similar to the hermaphrodite, but in it 
there are only the rudiments of a style. The 
fruit is a smooth black drupa, round-shaped, 
and of the size of a pea. Except the pulp of 
the fruit, every other, part of this tree has an 
intensely bitter taste. In taste ahd virtues it 
is nearly equal to the quassia of Surinam. 
The happiest effects result from the use of this 
medicine in obstinate remitting fevers from 
marsh-miasmata, in agues which had resisted 
the use of Jesuits’ bark, and in dysenteries of 
long standing. It is in daily practice in dropsies 
from debility, either in simple infusions or 
tincture by itself, or joined with aromatics 
and chalybeates. Dr. Drummond, an emi- 
nent physician in Jamaica, prescribes it with 
great success in the above cases, as well as in 
amenorrhoea, chlorosis, dyspepsia, and in that 
species of pica called dirt-eating, so fatal to a 
number of negroes. 
The bark of the quassia polygama, but es- 
pecially the wood, is intensely bitter. They 
may both be used in various forms. In cer- 
tain cases of dropsy, aromatics aird prepara- 
tions are joined to it, also in amenorrhoea ad 
chlorosis; and in worm fevers, the cabbage- 
bark, or other vegetable anthelmintics. 
Quassia, in chemistry. Many vegetable 
substances have an intensely bitter taste, anci 
on that account are employed in medicine, 
by brewers, &c. This is the case with the 
wood of the quassia amara and excelsa, the 
common quassia of the shops; with the roots 
of the,gentiana lutea, common gentian; the 
leaves of the humulus lupulus or hop ; the 
bark and wood of the spartium scoparium, or 
common broom; the flowers and leaves of* 
the anthemis nobilis or chamomile ; and many 
other substances. These bodies owe their 
bitter taste to the presence of a peculiar ve- 
getable substance differing from every other, 
which may be distinguished by the name of 
the bitter principle. 
No chemical examination of this substance 
has been hitherto published ; nor indeed are 
we in possession of any method of separating 
it from other bodies, or of ascertaining its 
presence. At the same time it cannot be 
doubted that it possesses peculiar characters ; 
and its action on the animal economy renders 
it an object of importance. 
1 . When water is digested over quassia for 
some time, it acquires an intensely bitter 
taste and a yellow colour, but no smell. 
When water thus impregnated is evaporated 
to dryness in a low heat, it leaves a brownish- 
yellow substance, which retains a certain de- 
gree of transparency. It continues ductile 
for some time, but at last becomes brittle. 
This substance we might consider as the bit- 
ter principle in a state of purity. If it con- 
tains any foreign body it must be in a very 
minute proportion. This substance is found 
to possess the following properties: l.Its 
taste is intensely bitter. Colour brownish- 
yellow. 2. When heated, softens, and swells, 
and blackens ; then burns away without flam- 
ing much, and leaves a small quantity of 
ashes. 3. Very soluble in water and in al- 
cohol. 4. Does not alter the colour of in- 
fusion of litmus. 5. Lime water, barytes 
water, and strontian water, occasion no pre- 
cipitate. Neither is any precipitate thrown 
down by silicated potass, aluminated potass, 
or sulphat of magnesia. 6. The alkalies oc- 
casion no change in the diluted solution of 
the bitter principle. 7. Oxalat of ammonia 
occasions no precipitate. 8. Nitrat of silver 
renders the solution muddy, and a very soft 
flaky yellow precipitate falls slowly to the 
bottom. 9. Neither corrosive sublimate nor 
nitrat of mercury occasions any precipitate. 
10. Nitrat of copper, and the ammoniacal 
solution of copper, produce no change; but 
muriat of copper gives the white precipitate, 
which falls when this liquid salt is dropt into 
water. 11. Sulphat and oxymtiriat of iron 
occasion no change. 12. Muriat of tin ren- 
ders the solution muddy, but occasions no 
precipitate, unless the solution is concen- 
trated; in that case a copious precipitate 
falls. 13. Acetat of lead occasions a very 
copious white precipitate. But the nitrat of 
lead produces no change. 14. Muriat of 
zinc occasions no change. 15. Nitrat of bis- 
muth produces no change, though when the 
salt is dropt into pure water a copious white 
precipitate appears. 16. Tartar emetic pro- 
duces no change; but when the muriat of 
.antimony is used, the white precipitate up- 
