Cooley's Cyclopaedia of Practical Receipts Volume I Part 255

Gallium resembles lead in appearance, but is less blue in colour. Exposed to moist air it tarnishes slightly. It is a little harder than lead, is flexible, malleable, and may be easily cut with a knife. If melted and poured upon gla.s.s, it adheres to it, and forms a mirror which is whiter than that caused by mercury. A red heat fails to volatilise it to any appreciable extent, and it is only slightly oxidised at that temperature; therefore it is not tarnished when exposed to the air. Hot nitric acid dissolves it, but the cold acid has scarcely any action on it. It melts at 3015 C. When once fused, it preserves the liquid condition even for several months at 0 C.,[324] until it is touched by some solid body, or by a piece of solid gallium, when it congeals to a crystalline solid, having a specific gravity of 593; when fused it has a specific gravity of 608. It crystallises in square octohedra. In properties gallium is more or less intermediate between the metals aluminium and indium.

[Footnote 324: In consequence of this curious property gallium was first described as a liquid metal.]

Chemical reactions of gallium:--The following are the chief reactions of the salts of gallium when in solution. With ammonia they give a white gelatinous precipitate, soluble, but not readily in excess of the precipitant; potash gives a similar precipitate, soluble in excess; acetate of ammonia, on boiling in a solution free from excess of acid, precipitates a basic compound; barium carbonate readily precipitates gallium salts in the cold. A sulphate and a chloride of gallium have already been obtained. These salts are both very soluble; the sulphate is a non-deliquescent substance, the chloride, on the contrary, is excessively so, and decomposed by a large excess of water. Gallium also forms an alum consisting of the double sulphate with ammonium. Gallium alum is a beautifully crystalline body, more soluble in cold than in hot water.

At a meeting of the 'Academie des Sciences' in March, 1878, M. de Baubradon stated that he had determined the atomic weight of gallium. The mean of two experiments showed it to be 699.

The 'Comptes Rendus' for February, 1878 (No. 7), contains a communication from MM. Lecoq de Boisbaudran and E. Jungfleisch, on the extraction of gallium from the ores in which it is found a.s.sociated with indium.

The following is the process given by the authors:--The blende of Bendsberg is pulverised and then roasted in a Perret furnace, by which treatment the greater part of the indium is volatilised. The residue is treated with sulphuric acid in quant.i.ty sufficient to dissolve almost all the zinc, and there is thus obtained a residue which is treated with excess of sulphuric acid.

The persalts of iron present are then reduced by means of metallic zinc, and the filtrate fractionally precipitated with carbonate of sodium; the precipitates are redissolved in sulphuric acid, and the reduction with zinc and the fractional precipitation repeated, the latter operation being in both cases watched by the spectroscope.

The precipitate containing the gallium concentrated in a small bulk, is redissolved in acid, and the excess of the latter reagent removed by evaporation, after which it is boiled with much water. The filtrate separated from the sediment containing t.i.tanic acid, which form is treated with sulphuretted hydrogen, then mixed with acetate of ammonium and again treated with sulphuretted hydrogen, which throws down the galliferous sulphide of zinc free from alumina. Again the precipitate is dissolved in sulphuric acid, and the solution fractionally precipitated with carbonate of sodium, which operation, guided as it is by spectral examination, entirely removes the zinc. By once more dissolving in the exactly necessary amount of sulphuric acid, and treating with sulphuretted hydrogen, cadmium, lead, indium and zinc are removed, and the filtrate is then largely diluted with water and boiled. The bulky sub-salt of gallium which separates at this temperature is treated with potash, which leaves iron, indium, &c., undissolved, and the alkaline liquor when treated with sulphuretted hydrogen, and subsequently with sulphuric acid to slight acidity, yields a deposit consisting mainly of sulphide of indium.

The slightly acid liquid is then boiled with much water, and the deposit of sub-salt of gallium thus obtained is dissolved in potash, and the solution subjected to electrolysis, by which means a metallic deposit of gallium is obtained.

It is interesting to note how accurately many of the chemical physical properties to gallium had, previously to its discovery, been predicted by the Russian chemist, Mendelejeff, by reasoning on the so-called "periodic law," which he thus defines:--"The properties of the simple bodies, as also the properties and const.i.tution of their combinations, are periodic functions of the atomic weights of the elements."

In 1864 an English chemist named Mr Newlands, observing certain relations existing between the atomic weights of many of the elements, was the first to arrange them in such a manner or serial form as to suggest that when certain gaps were observed in the atomic weights of a series, new elements might be a.s.sumed to exist. Guided by this theory, Mendelejeff affirmed that the "periodic law" not only indicates vacancies in the cla.s.sificatory scheme of the known elements, but enables us to predict the properties of elements as yet undiscovered, and of their compounds. Thus, of one of the vacancies observable in the table of the elements arranged according to his cla.s.sification, Mendeljeff a.s.serted, that should the element (which he named _Eka aluminium_) with the corresponding atomic number be discovered, it would possess the following characteristics:--It would most probably, like indium and thallium, be discovered by the aid of spectrum a.n.a.lysis.

Gallium, as we have seen, was found by this means. The formula of its oxide would be El_{2}O_{3}; the oxide of gallium is best represented by Ga_{2}O_{3}.

The salts would have the general formula ElX_{3}; the salts of gallium have most probably the general formula GaX_{3}. It will form an alum isomorphous with common alum, this we have seen gallium does. Its salts would be precipitable by barium carbonate; the gallium salts are thrown down by this reagent. It would not oxidise in the air; gallium does not tarnish upon exposure to the air. It would decompose water at a red heat; gallium readily does this at high temperatures. Its specific gravity (and this is very remarkable) would be about 59; gallium has a specific gravity of 593. Its atomic weight would be about 68; that of gallium is 699.

The hypothetical _Eka aluminium_ of Mendelejeff appears therefore to correspond with the gallium of Boisbaudran.

=GALLS.= _Syn._ GALL-NUTS, NUT-GALLS; GALLA (B. P.); GALLae (Ph. E.).

"Excrescences on _Quercus infectoria_ caused by the puncture and deposited ova of _Diplolepis Gallae tinctoriae_." The best galls are blueish-black, heavy, and not yet perforated; intensely astringent. They are imported from Aleppo, and are known in commerce as black or blue galls (GALLae NIGRae, G. CRULae). The next quality is termed, from their colour, green galls (GALLae VIRIDES). Both are gathered before the insect has escaped, and are styptic and powerfully astringent. White galls (GALLae ALBae) are lighter, less astringent, and inferior.

_Uses, &c._ Galls are extensively employed in the art of dyeing, and const.i.tute one of the princ.i.p.al ingredients in all the shades of black, and are also employed to fix or improve several other colours. A decoction of galls, to which a little green copperas and gum Arabic has been added, forms common writing ink. In _medicine_ they are used as an astringent, in haemorrhages and fluxes, in doses of 10 to 20 gr.; and topically, under the form of infusion or decoction, as a gargle in relaxation of the uvula; as an injection in gleet and leucorrha; as a lotion or fomentation in flabby ulcers, prolapsus ani, &c.; and as an ointment in piles, watery ulcers, &c. The infusion or decoction is also used as an antidote to poisoning by the alkaloids, and was formerly given as a tonic in intermittents. See GALLIC ACID, INK, &c.

=GALL'STONE.= _Syn._ CALCULUS BILIOSUS, C. CYSTICUS BOVINUS, L. Formed in the gall-bladder of neat cattle in winter, when they are fed upon dry food. Used as a yellow pigment, and in medicine--_Dose_, 1 gr.; in dyspepsia and flatulency. Man is also subject to gall-stone, the presence or pa.s.sage of which is attended with the most acute pain, frequently accompanied with nausea and sickness. In no case should a patient suffering from a paroxysm such as above described delay to seek immediate medical aid. The following treatment is recommended for the benefit of those only who, like emigrants and others, may be unable to obtain professional a.s.sistance.

The pain and spasm should be endeavoured to be alleviated by full doses of laudanum, given in soda water. If there be much sickness, the laudanum should be given in the form of an enema. If the paroxysm be excessive, the cautious inhalation of ether or chloroform should be tried. When the pain is of long duration, leeching should be had recourse to. Ice applied freely to the pit of the stomach has sometimes been found to give relief.

See CALCULUS.

=GALV'ANIZED IRON.= See IRON and ZINCING.

=GAM'BOGE.= _Syn._ (CAMBOGE; CAMBOGIA, L. B. P.) GAMBOGIA, L. "A gum-resin obtained from _Garcinia Morella_." (B. P.) Gamboge is an active hydragogue and drastic purgative, which occasionally proves useful in torpor of the abdominal and pelvic viscera; but which is highly dangerous in an irritable or inflammatory state of the stomach or bowels, and during pregnancy. It is very apt to induce nausea and vomiting. In large quant.i.ties it is a violent poison. "The deaths which have occurred from the use of enormous quant.i.ties of Morrison's pills are mainly ascribable to the gamboge contained in those medicines." (Pereira.)--_Dose_, 1 to 5 gr., made into pills or mixture, every 4 to 6 hours; in obstinate constipation, in dropsies, in apoplexy and like cerebral affections, and in worms (especially tape-worm), either alone or combined with other cathartics. See COMPOUND EXTRACT OF COLOCYNTH.

=GAME.= The flesh of game is believed to possess strengthening qualities superior to that of poultry. It also contains less fat. Game is tender and easy of digestion, and it has a delicate and marked flavour. It forms a valuable diet for the invalid, by reason of its easy digestibility.

Respecting the choice and preservation of game, Eliza Acton writes--"Buck venison, which is in season only from June to Michaelmas, is considered finer than doe venison, which comes into the market in October, and remains in season through November and December; neither should be cooked at any other part of the year.

"The greater the depth of fat upon the haunch the better the quality of the meat will be, provided it be clear and white, and the lean of a dark hue.

"If the cleft of the hoof, which is always left on the joint, be small and smooth, the animal is young; but it is old when the marks are the reverse of these.[325] Although the haunch is the prime and favourite joint of venison, the neck and shoulder are also excellent, dressed in various ways, and make much-approved _pasties_. A free current of air in a larder where venison is kept is always a great advantage.

[Footnote 325: Venison is not in perfection when young.]

"All moisture should be wiped daily, or even more frequently, from the venison with soft cloths, when any appears upon the surface, and every precaution must be taken to keep off the flies when the venison is not hung in a wire safe. Black pepper thickly powdered on it will generally answer the purpose.

"Hares and rabbits are stiff when freshly killed, and if young the ears tear easily, and the claws are smooth and sharp. A hare in cold weather will remain good for ten or fourteen days; care only must be taken to prevent the inside from becoming musty, which it will do if it has been emptied in the field. Pheasants, partridges, and other game, may be chosen by nearly the same tests as poultry--by opening the bill the staleness will be detected easily if they have been kept too long by the hardness of the bill. With few exceptions game depends almost entirely for the fine flavour and the tenderness of its flesh, on the time which it is allowed to hang before it is cooked, and it is never good when very fresh; but it does not follow that it should be sent to table in a really offensive state."

=Game, Hashed.= _Ingredients._--The remains of cold game, one onion stuck with three cloves, a few whole peppers, a strip of lemon peel, salt to taste, thickening of b.u.t.ter and flour, one gla.s.s of port wine, one tablespoonful of lemon juice, one tablespoonful of ketchup, and one pint of water or weak stock.

Proceed as follows:--Cut the remains of cold game into joints, reserve the best pieces, and put the inferior ones and the tr.i.m.m.i.n.gs into a stewpan with the onion, pepper, lemon peel, salt, and water or weak stock; stew these for about an hour, and strain the gravy; thicken it with b.u.t.ter and flour; add the wine, lemon juice, and ketchup; lay in the pieces of game, and place them by the side of the fire until they are warmed through, avoiding boiling, otherwise the game will become too hard. Just on the point of simmering serve, and garnish the dish with sippets of toasted bread. _Time._ Altogether, an hour and a quarter.

? The above recipe applies to any kind of game.

If desirable, the flavour may be varied by adding flavoured vinegars, curry powder, &c.; these, however, cover the gamey taste of the dish, and are, therefore, not to be recommended.

=Grouse, to Roast.= _Ingredients._--Grouse, b.u.t.ter, a thick slice of toasted bread. _Mode._--Let the birds hang as long as possible; pluck and draw them; wipe (but do not wash them) inside and out, and truss them without the head, the same as for a roast fowl. Put them down to a sharp clear fire, keep them well basted the whole of the time they are cooking, and serve them on b.u.t.tered toast, soaked in the dripping-pan, with a little melted b.u.t.ter poured over them, or with bread sauce and gravy.

_Time._ Half an hour; if liked thoroughly done, thirty-five minutes.

Seasonable from the 12th of August to the beginning of December. (Mrs Beeton.)

=Hare, Jugged.= _Ingredients._--One hare, a bunch of sweet herbs, two onions, each stuck with three cloves, six whole allspice, half a teaspoonful of black pepper, a strip of lemon peel, thickening of b.u.t.ter and flour, two table-spoonfuls of mushroom ketchup, quarter of a pint of port wine. _Mode._--Wash the hare nicely, cut it up into joints (not too large), and flour and brown them; then put them into a stewpan with the herbs, onions, cloves, allspice, pepper, and lemon peel; cover them with hot water, and when it boils carefully remove all the sc.u.m, and let it simmer gently till tender, which will be in about 1-3/4 hour, or longer should the hare be very old. Take out the pieces of hare, thicken the gravy with flour and b.u.t.ter, add the ketchup and port wine, let it boil for about ten minutes, strain it through a sieve over the hare, and serve.

A few fried forcemeat b.a.l.l.s should be added at the moment of serving, or, instead of frying them, they may be stewed in the gravy, about ten minutes before the hare is wanted for use. Do not omit to serve red-currant jelly with it. _Time._ Altogether, two hours. Seasonable from September to the end of February. (Mrs Beeton.)

=Hare, to Roast.= _Ingredients._--Hare, forcemeat, a little milk, and b.u.t.ter. To be eaten in perfection, the hare must hang for some time. After it is skinned wash it well, and soak it for an hour in warm water to draw out the blood. Make a forcemeat, wipe the hare dry, fill the belly with it, and sew it up. Bring the hind and fore legs close to the body towards the head, run a skewer through each, fix the head between the shoulders by means of another skewer, and be careful to leave the ears on. Put a string round the body from skewer to skewer and tie it above the back.

_Mode._--The hare should be kept at a distance from the fire when it is first laid down. Baste it well with milk for a short time, and afterwards with b.u.t.ter; and particular attention must be paid to the basting, so as to preserve the meat on the back juicy and nutritive. When it is almost roasted enough, flour the hare, and baste well with b.u.t.ter. When nicely frothed dish it, remove the skewers, and send it to table with a little gravy in the dish, and a tureen of the same. Red-currant jelly must be served with it. If the liver is good it may be parboiled, minced, and mixed with the stuffing; but it should not be used unless quite fresh.

_Time._ A middling-sized hare an hour and a quarter; a large hare one and a half to two hours. (Mrs Beeton.)

=Partridges, to Roast.= Let the birds hang as long as they can possibly be kept without becoming offensive; pick them carefully, draw and singe them, wipe the insides thoroughly with a clean cloth, truss them with the head turned under the wing and the legs drawn close together, not crossed.

Flour them when first laid to the fire, and baste them plentifully with b.u.t.ter. Serve them with bread sauce and good brown gravy; a little of this last should be poured over them. _Time._ 30 or 40 minutes. In preparing them for the spit the crop must be removed through a slit cut in the back of neck, the claws clipped close, and the legs held in boiling water for a minute, that they may be skinned more easily. (Eliza Acton.)

=Pheasant, to Roast.= Let it hang as many days as possible without becoming tainted. Pluck off the feathers carefully, cut a slit in the back of the neck to remove crop, then draw the bird in the usual way, and either wipe the inside very clean with a damp cloth, or pour water through it; wipe the outside also, but with a dry cloth; cut off the toes, turn the head of the bird _under_ the wing, with the bill laid straight along the breast; skewer the legs, which must not be crossed; flour the pheasant well, lay it to a brisk fire, and baste it constantly and plentifully with well-flavoured b.u.t.ter. Send bread sauce and good brown gravy to table with it. _Time._ Three quarters of an hour, a few minutes less if liked very much underdone, five or ten more for thorough roasting, with a _good_ fire in both instances. In season from October to the end of January. (Eliza Acton.)

=Rabbit, to Boil.= Rabbits that are three parts grown, or, at all events, which are still quite young, should be chosen for boiling. Wash them well, truss them firmly, with the heads turned and skewered to the sides, drop them into sufficient boiling water to keep them quite covered until they are cooked, and simmer them gently from thirty to forty-five minutes; when _very_ young they will require even less time than this. Cover them with rich white sauce mixed with livers parboiled, finely pounded, and well seasoned with cayenne and lemon juice; or with white onion sauce, or with parsley and b.u.t.ter, made with milk or cream instead of water (the livers, minced, are often added to the last of these), or with good mushroom sauce. _Time._ 30 to 45 minutes. (Eliza Acton.)

=Rabbit, to Roast.= This is much improved by having the backbone taken out. When this is done line the inside with thin slices of bacon, fill it with forcemeat, sew it up, truss, and roast it at a clear, brisk fire, and baste it constantly with b.u.t.ter. Flour it well soon after it is laid down.

Serve it with good brown gravy, and with currant jelly, when this last is liked. _Time._ 3/4 hour to 1 hour; less if small. (Eliza Acton.)

=Venison, Haunch of, to Roast.= To prepare the venison for the spit wash it slightly with tepid water, or merely wipe it thoroughly with damp cloths, and dry it afterwards with clean ones; then lay over the fat side a large sheet of thickly-b.u.t.tered paper, and next a paste of flour and water about three quarters of an inch thick; cover this again with two or three sheets of stout paper, secure the whole well with twine, and lay the haunch to a sound, clear fire; baste the paper immediately with b.u.t.ter or clarified dripping, and roast the joint from three hours and a half to four and a half, according to its weight and quality. Doe venison will require half an hour less time than buck. Twenty minutes before the joint is done remove the paste and paper, baste the meat in every part with b.u.t.ter, and dredge it very lightly with flour; let it take a pale-brown colour, and send it to table as hot as possible, with gravy in a tureen and good currant jelly. _Time._ 3-1/2 to 4-1/2 hours. The kind of gravy appropriate to venison is a matter on which individual taste must decide.

(Eliza Acton.)

=Venison, Hashed.= _Ingredients._--The remains of roast venison, its own or mutton gravy, thickening of b.u.t.ter and flour. _Mode._--Cut the meat from the bones in neat slices, and, if there is sufficient of its own gravy left, put the meat into this, as it is preferable to any other.

Should there not be enough put the bones and tr.i.m.m.i.n.gs into a stewpan with about a pint of mutton gravy; let them stew gently for an hour, and strain the gravy. Put a little flour and b.u.t.ter into the stewpan, keep stirring until brown, then add the strained gravy, and give it a boil up; skim and strain again, and when a little cool put in the slices of venison. Place the stewpan by the side of the fire, and when on the point of simmering serve. Do not allow it to boil. Send red-currant jelly to table with it.

_Time._ Altogether, an hour and a half. A small quant.i.ty of Harvey sauce, ketchup, or port wine, may be added to enrich the gravy.

=GAN'GRENE.= See MORTIFICATION.

=GAN'TEINE.= A composition used to clean kid and other leather gloves.

_Prep._ 1. (M. Buhan.) Curd soap (in small shavings), 1 part; water, 3 parts; mix with heat, and stir in of essence of citron, 1 part.

2. (SAPONINE,--Duvignau.) Soap (in powder), 250 parts; water, 155 parts; dissolve with heat, cool, and add, of _eau de javelle_, 165 parts, solution of ammonia, 10 parts, and rub the whole to a smooth paste.

Patent. A small portion of either of the above is rubbed over the glove with a piece of flannel (always in one direction), until it is sufficiently clean. See GLOVES.