=Enamel, Ol'ive.= _Prep._ Blue enamel, 2 parts; black and yellow enamel,
of each, 1 part. See ENAMEL BROWN.
=Enamel, Or'ange.= _Prep._ 1. Red lead, 12 parts; red sulphate of iron and
oxide of antimony, of each, 1 part; flint powder, 3 parts; calcine
together, powder, and melt with 'flux,' 50 parts.
2. (Wynn.) Red lead, 12 parts; oxide of antimony, 4 parts; flint powder, 3
parts; red sulphate of iron, 1 part; calcine, then add 'flux,' 5 parts, to
every 2 parts of this mixture.
=Enamel, Pur'ple.= _Prep._ 1. 'Flux' or 'frit,' coloured with oxide of
gold, purple precipitate of cassius, or peroxide of manganese.
2. Sulphur, nitre, green vitriol, antimony, and oxide of tin, of each, 1
lb.; red lead, 60 lb.; mix, fuse, cool, powder, and add rose copper (red
oxide), 19 oz.; zaffre, 1 oz.; crocus martis, 1-1/2 oz.; borax, 3 oz.; and
of a compound formed of gold, silver, and mercury, 1 lb.; fuse, stirring
the melted mass with a copper rod all the time, then place it in
crucibles, and submit them to the action of a reverberatory furnace for 24
hours. This is said to be the purple enamel used in the mosaic pictures in
St. Peter's at Rome.
=Enamel, Red.= _Prep._ 1. 'Paste' or 'flux,' coloured with the red oxide
or protoxide of copper. Should the colour pass into the green or brown,
from the partial peroxidation of the copper, from the heat being raised
too high, the red colour may be restored by the addition of any
carbonaceous matter, as tallow, or charcoal.
2. By tinging the glass or 'flux' with the oxide or salts of gold, or with
the purple precipitate of cassius. These substances produce shades of red,
inclining to crimson or purple of the most exquisite hue. The enamel often
comes from the fire quite colourless, and afterwards receives its rich hue
at the lamp.
3. (Wynn.) Sulphate of iron (calcined dark), 1 part; a mixture of 6 parts
of 'flux' (No. 5), and 1 of colcothar, 3 parts. Dark red.
4. (Wynn.) Red sulphate of iron, 2 parts; 'flux' (No. 1), 6 parts; white
lead, 3 parts. Light red.
=Enamel, Rose-col'oured.= _Prep._ Purple enamel (or its elements), 3
parts; 'flux,' 90 parts; mix, and add silver leaf or oxide of silver, 1
part, or less.
=Enamel, Transpa''rent.= The 'frit' or 'flux' described _above_.
=Enamel, Vi'olet.= _Prop._ 1. Purple enamel, 2 parts; red enamel (No. 2),
3 parts; 'frit,' 6 parts.
2. Saline or alkaline 'frit' or 'flux,' any quantity; peroxide of
manganese, q. s. to colour. As the tint depends on the metal being at the
maximum of oxidation, contact with oily or carbonaceous substances should
be particularly avoided.
=Enamel, White.= _Prep._ 1. 'Calcine' (from 2 parts of tin and 1 part of
lead), 1 part; fine crystal glass or 'frit,' 2 parts; manganese, a few
grains; powder, mix, melt, and pour the fused mass into clean water; again
powder, and fuse, and repeat the whole process 3 or 4 times, avoiding
contamination with smoke, dirt, or oxide of iron. A fine dead white.
2. Washed diaphoretic antimony, 1 part; fine glass (free from lead), 3
parts; mix, and proceed as before. Very fine.
3. Lead, 30 parts; tin, 33 parts; calcine as before, then fuse 50 parts of
this 'calcine' with an equal weight of flints, in powder, and 100 parts of
salt of tartar. A fine dead white enamel.
_Obs._ For white enamel, the articles must be perfectly free from foreign
admixture, as this would impart a colour. When well managed, either of the
above forms will produce a paste that will rival the OPAL.
=Enamel, Yellow.= Superior yellow enamels are less easily produced than
those of most other colours; they require very little flux, and that
mostly of a metallic nature. The following come highly recommended by
experienced artists:--
_Prep._ 1. From 'frit' or 'flux,' fused with oxide of lead, and a little
red oxide of iron.
2. Lead, tin, ashes, litharge, antimony, and sand, of each 1 oz.; nitre, 4
oz.; mix, fuse, and powder; and add the product to 'flux' or 'frit,' q. s.
3. White oxide of antimony, alum, and sal-ammoniac, of each 1 part; pure
carbonate of lead, 1 to 3 parts, or q. s. (all in powder); mix, and expose
them to a heat sufficiently high to decompose the sal-ammoniac. Used as
the last. Very bright coloured.
4. (Wynn.) Red lead, 8 oz.; oxide of antimony, and tin, calcined together,
of each 1 oz; mix, and add of 'flux' (No. 5), 15 oz.; mix well and fuse.
5. Pure oxide of silver added to the metallic 'fluxes.' The salts of
silver are also used, but are more difficult to manage. If a thin film of
oxide of silver be spread over the surface of the enamel to be coloured,
exposed to a moderate heat, then withdrawn, and the film of reduced silver
on the surface removed, the part under will be found tinged of a fine
yellow. (Clouet.)
=Enamelling of Cast-Iron.= Wagner in his 'Chemical Technology' gives the
following account of this process:--The surface of the cast-iron to be
enamelled is first carefully cleaned by scouring with sand and dilute
sulphuric acid, next a somewhat thickish magma, made of pulverised quartz,
borax, feldspar, kaolin and water is brushed over the clean metallic
surface as evenly as possible, and immediately after a finely powdered
mixture of feldspar, soda, borax, and oxide of tin, is dusted over, after
which the enamel is burnt in by the heat of a muffle. In France an enamel
is applied which consists of 130 parts of flint glass, 20-1/2 parts of
carbonate of soda, and 12 parts of boric acid fused together, and
afterwards ground to a fine powder.
It would appear, however, from the statements contained in a paper read by
Mr Tatlock, F.R.S.E., F.C.S., that the enamel used for iron vessels is
frequently of a less harmless kind than that described by Wagner. Mr
Tatlock states that in some instances the milk-white porcelainous enamel,
with which cast-iron cooking vessels are now so commonly prepared, has a
composition such as to render it highly objectionable, on account of the
facility with which it is acted upon by acid, fruits, common salt, and
other ordinary dietetic substances, by which means lead, and even arsenic,
are dissolved out in large quantity during cooking processes.
Mr Tatlock gives the analysis of three samples of enamel from the interior
of three cast-iron pots obtained from different manufacturers. These iron
vessels were all employed for cooking:--
No. 1. No. 2. No 3.
per cent. per cent. per cent.
Silica 61·00 42·40 42·00
Alumina 8·00 2·88 6·06
Oxide of iron 1·10 2·04 4·04
Lime 3·02 0·16 0·78
Magnesia 0·28 0·10 0·21
Oxide of lead absent 25·89 18·48
Potash 5·61 7·99 6·46
Soda 20·67 14·67 19·25
Phosphoric acid trace trace trace
Arsenious acid 0·02 0·42 1·02
Carbonic acid 0·30 absent absent
Borax absent 3·45 1·70
------- ------- -------
100·00 100·00 100·00
------- ------- -------
Total bases 38·58 53·73 55·28
The author showed that it was not so much on account of the presence of
large proportions of lead and arsenic that the enamels are so dangerous,
but because they are so highly basic in character, that they are acted
upon with facility by feebly acid solutions, the lead and arsenic being
thereby easily dissolved out.
He demonstrated that the ratio of the bases to the silica in No. 1 was 1
to 1·58; in the No. 2, as 1 to 0·79; and in the No. 3, as 1 to 0·76. A one
per cent. solution of citric acid boiled in the No. 1 did not affect it in
the slightest, while in the case of the No. 3, the glassy surface of the
enamel was at once roughened and destroyed, and lead dissolved out to such
an extent as to give immediately a dense black precipitate with
sulphuretted hydrogen. He thought that no enamel was fit to be used unless
it were totally unaffected by boiling with a one per cent. solution of
citric acid, which was a very moderate test, and gave it as his opinion
that either the use of such poisonous ingredients as lead and arsenic in
large quantity should be entirely abandoned, or that the composition
otherwise of the enamel should be of such a character as to ensure that
none of the poisonous substances could be dissolved out, in the
circumstances under which the enamelled vessels are used.
=ENCAU'STIC.= See PAINTING (Encaustic).
=ENDEMIC.= Indigenous. Peculiar to a district. Those are called endemic
diseases, which are produced by causes more or less local. The word is
often confounded with epidemic.
=ENE'MA.= _Syn._ CLYSTER; EN'EMA (pl. ENEM'ATA), L. A medicine, usually
liquid (sometimes gaseous), thrown into the rectum or lower bowels.
Clysters usually consist of some weak glutinous or mucilaginous fluid, to
which the active ingredients are added; or a decoction or infusion is made
of the medicaments, which is then used, either alone, or after the
addition of a little gum, starch, or sugar. The proper vehicle for
astringent vegetable matter, metallic salts, and the mineral acids, is
pure water. Oleaginous and resinous substances are made into emulsions
before being employed for enemas. In all cases the fluid is administered
warm. The quantity of fluid forming a clyster, for an adult, may vary from
1/2 to 3/4 pint; that for an infant within a month old, should be about 1
fl. oz.; for a child of one year, about 2-1/2 fl. oz.; from one to seven
years, from 3 or 4 fl. oz.; and from seven to twelve or fourteen, 6 or 7
fl. oz.; after that age to puberty, 1/2 pint may be employed.
The quantity or dose of the active ingredients in a clyster should be 4 or
5 times as great as that of the same medicines when taken by the mouth; as
it is generally regarded that the susceptibility of the rectum is only
1/5th that of the stomach, and that to exert a like absorbent action it
occupies 5 times as long as the latter viscus. The dose, and the interval
between its repetition, should, therefore, be proportionately increased.
Narcotics, as opium, tobacco, &c., should, however, be given in only twice
or thrice the quantity that would be exhibited in the usual manner.
Enemata are usually administered by means of a syringe, bladder, or
elastic bag, furnished with a rectum tube; but many ingenious and elegant
pieces of mechanism, adapted for self-administration, are made by the
instrument makers. Great care should be taken to avoid injuring the coats
of the rectum by the use of a rough or improperly shaped pipe, or one that
is too long. The extremity of the pipe or tube should also be perfectly
smooth and well rounded (rather spherical than pointed), and in using it
no force should be employed. A neglect of this point often produces very
serious consequences, especially in young children.
Tobacco smoke may be administered by means of a double pair of bellows,
supplied with air from a small funnel under which the herb is
burning,--and gaseous matter, by connecting the rectum tube with a small
gasometer, exerting a trifling pressure on the confined gas.
The number of substances employed in the preparation of enemata is very
great. The following are some of them, arranged according to their
effects:--
1. (Anodyne and Narcotic.) Opium, henbane, &c., are employed to allay
spasms of the bowels, stomach, uterus, bladder, &c.
2. (Aperient or Cathartic.) Aloes, colocynth, senna, various purging
salts, gruel, decoction of marshmallows, decoction of linseed, warm water,
&c., are commonly employed to promote the peristaltic action of the
bowels, or to destroy worms.
3. (Demulcent and Emollient.) Decoction of starch, gum, isinglass, glue,
&c., either alone or combined with opium, are used to protect the coats of
the intestines, and to allay irritation; and also to restrain diarrh[oe]a,
especially when combined with astringents, as logwood, catechu, or oak
bark.
4. (Nutrient.) Animal jelly, soups, broths, milks, &c., are frequently
used as injections to convey nourishment to the body.
5. (Sedative.) Tobacco infusion or smoke, and tartar emetic (in solution),
are employed to relax the powers of the body, to remove spasms, depress
the circulation, and to produce syncope.
Enemata or clysters are now very frequently employed in our large towns,
especially among the higher classes; but a great prejudice exists among
many persons against their use, arising from a fastidious and mistaken
delicacy. The introduction of improved apparatus of late years, by which
the administration of these remedies is attended with less difficulty and
exposure than formerly, has removed much of the repugnance which
previously existed.
Clysters are invaluable when it is necessary to evacuate the bowels as
speedily as possible, and when the stomach will not bear the
administration of a purgative by the mouth, as well as in cases requiring
a direct medication of the lower bowels, as in dysentery, colic, &c. As a
mere laxative, an injection of tepid water, milk-and-water, or water
gruel, will generally be found sufficient. By the addition of 1 or 2
table-spoonfuls of common salt, Epsom salts, salad oil, or molasses, to
this laxative enema, it will form an excellent purgative one, which will,
in most cases, induce a full discharge. In all cases, the patient should
be directed to retain the injection for as long a time as possible, and
not to attempt to empty his bowels immediately after the reception of the
medicine. "In irritation of the bladder, rectum, or uterus, an anodyne
injection or enema often affords much relief. In diseases of the lower
bowels, clysters are also of almost indispensable utility, as also in the
dislodgment of ascarides seated in the rectum; nor are they less
beneficial in those cases of sudden sinking of the powers of life where
deglutition is impossible, and yet a prompt stimulating impression is
requisite to save the patient; under such circumstances, clysters of some
of the diffusible stimuli have proved of the greatest benefit."
The injection of large quantities of liquid matter into the bowels, as
well as the constant use of clysters (even of warm water only), is deemed
by the highest medical authorities to be injurious, and occasionally
dangerous. The practice should not, therefore, be allowed to grow into a
habit. The bowels continually accustomed to a stimulant cease to act
without one. The same remarks apply to aperients taken by the mouth.
The following formulæ embrace the whole of the enemas (ENEMATA) of the
'British Pharmacop[oe]ia,' as well as a few others in common use:--
=Enema of Albu'men.= _Syn._ ENEMA ALBUMINIS, L. _Prep._ (Ricord) Infusion
of linseed, 12 oz.; whites of 2 or 3 eggs; mix. In chronic diarrh[oe]a,
and as a nutritient clyster in debility from stomach diseases. The reason
for rejecting the yolks of the eggs is not very obvious, as the
preparation is much more effective with them.
=Enema of Al'oes.= _Syn._ ENEMA ALOËS (B. P.), L. _Prep._ From aloes, 2
scrup.; carbonate of potassa, 15 gr.; mucilage of starch, 1/2 pint. In
ascarides, atonic amenorrh[oe]a, &c. It should not be employed when
irritability of the rectum, bladder, or genitals, exists; nor in piles, or
when there is a tendency to prolapsus ani or prolapsus uteri.
=Enema, An'odyne.= See ENEMA OF OPIUM.
=Enema, Antispasmod'ic.= _Syn._ ENEMA ANTISPASMODICUM, L. _Prep._ From
tincture of assaf[oe]tida, 3 fl. dr.; laudanum, 30 to 60 drops; water
gruel or barley water, 1/2 pint. In spasmodic affections of the bowels.
(See _below_.)
=Enema of Assaf[oe]t'ida.= _Syn._ FETID CLYSTER, ANTISPASMODIC C.; ENEMA
ASSAF[OE]TIDA (B. P.), E. F[OE]TIDUM (Ph. E. & D.), L. _Prep._ 1. (B. P.)
Assaf[oe]tida, 30 gr.; water, 4 oz.; rub together until mixed.
2. (Ph. E.) To cathartic enema (Ph. E.), add of tincture of assaf[oe]tida,
2 fl. dr.