Cooley's Cyclopaedia of Practical Receipts Volume I Part 205

=Enamel, Brown.= _Prep._ 1. Manganese, 5 parts; red lead, 16 parts; flint powder, 8 parts; as before.

2. (Wynn.) Manganese, 9 parts; red lead, 34 parts; flint powder, 16 parts.

3. Red lead and calcined iron, of each, 1 part; antimony, litharge, and sand, of each, 2 parts. To be added in any required proportion to white 'frit,' according to the colour desired. A little oxide of cobalt or zaffre is frequently added to alter the shade.

=Enamel, Green.= _Prep._ 1. 'Flux' or 'frit,' 2 lbs.; black oxide of copper, 1 oz.; as before.

2. As the last, but adding red oxide of iron, 1/2 dr. Less decisive.

3. Copper dust and litharge, of each 2 oz.; nitre, 1 oz.; sand, 4 oz.; 'flux' or 'frit,' q. s.

4. From transparent 'frit,' any quant.i.ty; oxide of chromium, q. s. to colour. Colour superb; it will stand a great heat; in common hands, however, it frequently turns on the dead-leaf tinge.

5. Transparent 'flux,' 5 oz.; black oxide of copper, 20 to 40 gr.; oxide of chromium, 2 gr. Resembles the emerald.

6. From blue and yellow enamel mixed in the required proportions.

=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 ca.s.sius, 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 ma.s.s 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 pa.s.s 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 gla.s.s or 'flux' with the oxide or salts of gold, or with the purple precipitate of ca.s.sius. 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 quant.i.ty; 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 gla.s.s or 'frit,' 2 parts; manganese, a few grains; powder, mix, melt, and pour the fused ma.s.s 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 diaph.o.r.etic antimony, 1 part; fine gla.s.s (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 m.u.f.fle. In France an enamel is applied which consists of 130 parts of flint gla.s.s, 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 a.r.s.enic, are dissolved out in large quant.i.ty during cooking processes.

Mr Tatlock gives the a.n.a.lysis 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 6100 4240 4200 Alumina 800 288 606 Oxide of iron 110 204 404 Lime 302 016 078 Magnesia 028 010 021 Oxide of lead absent 2589 1848 Potash 561 799 646 Soda 2067 1467 1925 Phosphoric acid trace trace trace a.r.s.enious acid 002 042 102 Carbonic acid 030 absent absent Borax absent 345 170 ------- ------- ------- 10000 10000 10000 ------- ------- ------- Total bases 3858 5373 5528

The author showed that it was not so much on account of the presence of large proportions of lead and a.r.s.enic 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 a.r.s.enic being thereby easily dissolved out.

He demonstrated that the ratio of the bases to the silica in No. 1 was 1 to 158; in the No. 2, as 1 to 079; and in the No. 3, as 1 to 076. 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 gla.s.sy 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 a.r.s.enic in large quant.i.ty 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 circ.u.mstances 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 r.e.c.t.u.m 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 quant.i.ty 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 p.u.b.erty, 1/2 pint may be employed.

The quant.i.ty 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 r.e.c.t.u.m 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 repet.i.tion, should, therefore, be proportionately increased.

Narcotics, as opium, tobacco, &c., should, however, be given in only twice or thrice the quant.i.ty that would be exhibited in the usual manner.

Enemata are usually administered by means of a syringe, bladder, or elastic bag, furnished with a r.e.c.t.u.m 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 r.e.c.t.u.m 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 r.e.c.t.u.m 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.