BLUE. Indigo dissolved in oil of vitriol, and the acid partly neutralised
with salt of tartar or whiting.
GREEN. A solution of distilled verdigris.
LILAC. Liquid archil.
RED. Carmine dissolved in a solution of salt of tartar, or in spirits of
hartshorn.
VIOLET. Liquid archil, mixed with a little salt of tartar.
YELLOW. Tincture of turmeric.
The above colours are usually applied to the petals with the fingers.
=Flowers.= _Syn._ FLORES, L. Among chemists, this term is applied to
various pulverulent substances obtained by sublimation, as flowers of
antimony, benzoin, zinc, sulphur, &c. The term has been discarded from
modern chemical nomenclature, but is still commonly employed in familiar
language and trade.
=FLUID CAM'PHOR.= _Prep._ (Sir J. Murray.) From camphor (in powder), 1
dr.; freshly precipitated carbonate of magnesia, 2 dr.; cold distilled
water, 1 pint; the solution is effected by forcing in carbonic acid gas
under pressure. Each fl. oz. contains 3 gr. of camphor, and 6 gr. of
carbonate of magnesia. See ESSENCE OF CAMPHOR.
=FLUID MAGNE'SIA.= _Syn._ LIQUOR MAGNESIÆ CARBONATIS, L. M. BICARBONATIS,
L. The preparations sold under this name are mere solutions of freshly
precipitated carbonate of magnesia in water, formed by means of carbonic
acid gas, under powerful pressure, and long agitation. Those best known
are Sir J. Murray's and Mr Dinneford's, each fl. oz. of which is said to
contain about 17-1/2 gr. of the carbonate, but their actual richness in
the latter seldom exceeds 10 or 12 gr., and by the time they reach the
consumer is often as low as 5 or 6 gr. Recently precipitated carbonate of
magnesia placed in a bottle or other suitable vessel, which is then filled
by means of a soda-water apparatus with water fully charged with carbonic
acid gas, readily dissolves on slight and cautious agitation, and the
aërated water becomes saturated with magnesia. A scruple of carbonate of
magnesia put into a soda-water bottle, and thus treated, is all taken up
in from 20 minutes to half an hour, and the beverage continues beautifully
clear.
=FLUID-OZON= (J. Krohn, Munich, with a certificate from Justus von
Liebig). A mouth wash and toilet water. An aqueous solution of
permanganate of soda, 1 in 9, contaminated with traces of sodium sulphate
and chloride. (Wittstein.)
=FLUM'MERY.= A species of thick hasty-pudding made with oatmeal or rice,
flavoured with milk, cream, almonds, orange flowers, lemons, &c.,
according to fancy.
_Prep._ 1. (DUTCH FLUMMERY.) From blancmange and eggs, flavoured with
lemon peel and sweetened with sugar.
2. (FRENCH FLUMMERY.) From equal parts of blancmange and cream, sweetened,
and flavoured. The above are poured into forms, and served cold, to eat
with wine, spirit, cider, &c.
3. (A. T. Thomson.) Take oatmeal or groats, 1 quart; rub it for a
considerable time with hot water, 2 quarts; and let the mixture stand
until it becomes sour; then add another quart of hot water, and strain
through a hair sieve. Let stand till a white sediment is deposited,
decant the fluid portion, and wash the sediment with cold water. This is
now to be boiled with fresh water, until it forms a mucilage, stirring the
whole time. A light and nutritious food, during early convalescence.
=FLUOBORIC ACID.= _Syn._ BOROFLUORIC ACID. This may be easily prepared by
saturating hydrofluoric acid with boracic acid, keeping the mixture cool,
and then concentrating it in platinum vessels till dense fumes arise.
=FLUOHYDRIC ACID.= See FLUORIDE OF HYDROGEN.
=FLU'ORIDE OF HYDROGEN.= HF. _Syn._ FLUOHYDRIC ACID; HYDROFLUORIC ACID; A.
HYDROFLUORICUM, L. An acid composed of hydrogen and fluorine. It was
discovered by Scheele, but was first obtained in a pure state by
Gay-Lussac and Thénard, in 1810.
_Prep._ Pour concentrated sulphuric acid on half its weight of fluor spar,
carefully separated from siliceous earth, and reduced to fine powder. The
mixture must be made in a capacious leaden retort, and a gentle heat only
applied, and the evolved gas must be collected in a leaden receiver,
surrounded by ice.
_Prop., &c._ A colourless fluid below 59° Fahr., which speedily evaporates
in dense white fumes when exposed to the air. Its affinity for water
exceeds that of sulphuric acid, and its combination with that fluid is
accompanied with a hissing noise, and a considerable increase of its sp.
gr. up to a certain point. It attacks glass and silica, for which reason
it cannot be preserved in glass vessels. Bottles of lead, silver,
platinum, or pure gutta percha, are used to keep it in. It is highly
corrosive, instantaneously destroying the skin on contact, and producing
deep and serious ulcerations; its vapour is pungent, irritating,
irrespirable, and poisonous. With the bases it unites to form FLUORIDES.
In the arts, hydrofluoric acid is used for etching on glass.
=FLU'ORIDES.= Compounds of fluorine with metals and other basic radicals.
The fluorides of the metals are, with the exception of those of the
alkaline metals, insoluble in water, while the fluorides of hydrogen,
boron, and silicon, are gaseous, condensing at a low temperature to
volatile liquids.
=FLU'ORINE.= F. _Syn._ FLUORINIUM, L. An element that has not yet been
isolated, owing to its attacking and combining with every element or
compound that at present has been exposed to it, except oxygen. It is
presumably gaseous, and of a pale greenish-yellow colour.
=FLU'OSILICIC ACID.= _Syn._ FLUORIDE OF SILICON AND HYDROGEN;
HYDROFLUOSILIC ACID. _Prep._ From powdered fluor spar, and siliceous sand
or powdered glass, of each 1 part; concentrated sulphuric acid, 2 parts:
mix in a glass retort, apply a gentle heat, and pass the evolved gas into
water through a layer of mercury. Decomposition ensues, silica being
deposited in a gelatinous state, and hydrofluosilicic acid or fluosilic
acid remains in solution. The acid liquor is used as a test for potassium
and barium, with whose salts it yields nearly insoluble precipitates.
=FLUX.= _Syn._ FLUXUS, FLUOR, L. In _medicine_, a term formerly applied to
several diseases attended with a copious discharge, as diarrh[oe]a (FLUX),
dysentery (BLOODY FLUX), English cholera (BILIOUS FLUX), fluor albus
(WHITE FLUX), &c. These terms are still current among the vulgar.
=Flux.= In metallurgy, &c., a term applied to various substances of easy
fusibility, which are added to others which are more refractory, to
promote their fusion.
_Prep._ 1. (BLACK FLUX.) Nitre, 1 part; crude tartar or cream of tartar, 2
parts; mix, and deflagrate, by small quantities at a time, in a crucible,
heated to dull redness. The product consists of carbonate of potassa,
mixed with charcoal in a finely divided state. Used for smelting metallic
ores. It exercises a reducing action, as well as promotes the fusion. It
must be kept in a dry corked bottle.
2. (CHRISTISON'S FLUX.) Carbonate of soda (cryst.), 8 parts; charcoal (in
fine powder), 1 part; heat the mixture gradually to redness. For reducing
arsenic.
3. (CORNISH REDUCING FLUX.) Crude tartar, 10 parts; nitre, 4 parts; borax,
3 parts; triturate together.
4. (CORNISH REFINING FLUX, WHITE FLUX.) Crude tartar and nitre, equal
parts, deflagrated together. See BLACK FLUX.