Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 187

=RAD'ICLE.= _Syn._ RADICAL. According to the binary theory of the const.i.tution of saline compounds, every salt is composed, like chloride of sodium (NaCl), of two sides or parts, which are termed its radicals. That part of a salt which consists of a metal, or of a body exercising the chemical functions of one, is called the metallic, basic, or basylous radical; while the other part, which, like chlorine, by combining with hydrogen would produce an acid, is designated the chlorous or acidulous radical. Every salt, therefore, consists of a basic and of an acid radical. Sometimes radicals are elementary in their nature, when they are called _simple_; and sometimes they are made up of a group of elements, when they are termed _compound_. Some radicals, both simple and compound, have been isolated, while many have but a hypothetical existence. In the following formulae the vertical line separates the basic from the acid radicals, the former being on the left, the latter on the right:--

H F Hydrofluoric acid (_Fluoride of hydrogen_).

Na Cl Chloride of sodium.

K CN Cyanide of pota.s.sium.

Ca CO_{3} Carbonate of calcium.

NH_{4} Cl Chloride of ammonium.

C_{2}H_{5} NO_{2} Nitrite of ethyl.

=RAD'ISH.= The common garden radish (RAPHa.n.u.s, L.) is the root of _Rapha.n.u.s sativus_ (Linn.), one of the _Cruciferae_. There are several varieties. They are all slightly diuretic and laxative, and possess considerable power in exciting the appet.i.te. The seed is pressed for oil.

The horseradish (ARMORACIA, L.) belongs to a distinct genus.

=RAIN-GAUGE.= _Syn._ OMBOMETER, PLUVIAMETER, UDOMETER. An instrument for determining the quant.i.ty of water, which falls as rain, at any given place. A simple and convenient rain-gauge for agricultural purposes is formed of a wide mouthed funnel, or open receiver, connected with a gla.s.s tube furnished with a stop-c.o.c.k. The diameter of the tube may be exactly 1-100th that of the receiver, and if the tube be graduated into inches and tenths, the quant.i.ty of rain that falls may be easily read off to the 1-1000th of an inch. The instrument should be set in some perfectly open situation; and, for agricultural purposes, with its edge as nearly level with the ground as possible. Another form of gauge is furnished with a float, the height of which marks the amount of liquid. The diameter of the gauge should range between 4 and 8 inches. The quant.i.ty of water should be duly measured and registered at 9 a.m. daily.

Mr Symonds, F.R.B.S., has drawn the following code of instructions for the guidance of those registering the amount of rainfall at any locality:--

1. _Site._ A rain-gauge should not be set on a slope or terrace, but on a level piece of ground, at a distance from shrubs, trees, walls, and buildings--at the very least as many feet from their base as they are in height.

Tall growing flowers, vegetables, and bushes must be kept away from the gauges. If a thoroughly clear site cannot be obtained, shelter is most endurable from north-west, north, and east; less so from south, south-east, and west; and not at all from south-west or north-east.

2. _Old Gauges._ Old-established gauges should not be moved, nor their registration discontinued, until at least two years after a new one has been in operation, otherwise the continuity of the register will be irreparably destroyed. Both the old and the new ones must be registered at the same time, and the results recorded for comparison.

3. _Level._ The funnel of a rain-gauge must be set quite level, and so firmly fixed that it will remain so, in spite of any gale of wind or ordinary circ.u.mstances. Its correctness in this respect should be tested from time to time.

4. _Height._ The funnel of gauges newly placed should be one foot above gra.s.s. Information respecting height above sea level may be obtained from G. J. Symons, Esq., 64, Camden Square, N.W., London.

5. _Rust._ If the funnel of a j.a.panned gauge become so oxidised as to retain the rain in its pores, or threatens to become rusty, it should have a coat of gas tar or j.a.pan black, or a fresh funnel of zinc or copper should be provided.

6. _Float Gauges._ If the measuring rod is detached from the float it should never be left in the gauge; if it is attached to the float it should be pegged or tied down, and only allowed to rise to its proper position at the time of reading. To allow for the weight of the float and rod these gauges are generally so constructed as to show 0 only when a small amount of water is left in them. Care must always be taken to set the rod to the zero or 0.

7. _Can and Bottle Gauges._ The measuring gla.s.s should always be held upright. The reading is to be taken midway between the two apparent surfaces of the water.

8. _Date of Entry._ The amount measured at 9 a.m. on any day is to be set against the previous one, because the amount measured at 9 a.m. of, say, the 17th, contains the fall during fifteen hours of the 16th, and only nine hours of the 17th. (The rule has been approved by the meteorological societies of England and Scotland, cannot be altered, and is particularly commended to the notice of observers.)

9. _Mode of Entry._ If less than one tenth (10) has fallen, the cipher must always be prefixed; thus, if the measure is full up to the seventh line, it must be entered as 07--that is, no inches, no tenths, and seven hundredths. For the sake of clearness it has been found necessary to lay down an invariable rule that there shall always be two figures to the right of the decimal point. If there be only one figure, as in the case of one tenth of an inch (usually written 1), a cipher must be added, making it 10. Neglect of this rule causes much inconvenience. All columns should be cast _twice_--once up and once down--so as to avoid the same error being made twice. When there is no rain a line should be drawn rather than a cipher inserted.

10. _Caution._ The amount should always be written down before the water is thrown away.

11. _Small Quant.i.ties._ The unit of measurement being 01, observers whose gauges are sufficiently delicate to show less than that are, if the amount is under 005, to throw it away; if it is 005 to 010 inclusive, they are not to enter it as 01.

12. _Absence._ Every observer should train some one as an a.s.sistant; but where this is not possible, instructions should be given that the gauge should be emptied at 9 a.m. on the 1st of the month, and the water bottled, labelled, and tightly corked, to await the observer's return.

13. _Heavy Rains._ When very heavy rains occur it is desirable to measure immediately on their termination; and it will be found a safe plan, after measuring, to return the water to the gauge, so that the morning registration will not be interfered with. Of course, if there is the slightest doubt as to the gauge holding all the falls it must be emptied, the amount being previously written down.

14. _Snow._ In snow three methods may be adopted; it is well to try them all:--(1) Melt what is caught in the funnel by adding to the snow a previously ascertained quant.i.ty of warm water, and then deducting this quant.i.ty from the total measurement, enter the residue as rain. (2) Select a place where the snow has not drifted, invert the funnel, and, turning it round, lift and melt what is enclosed. (3) Measure with a rule the average depth of snow, and take one twelfth as the equivalent of water. Some observers use in snowy weather a cylinder of the same diameter as the rain-gauge, and of considerable depth. If the wind is at all rough all the snow is blown out of a flat-funnelled rain-gauge.

15. _Overflow._ It would seem needless to caution observers on this head, but as a recent foreign table contains _six instances in one day_, in which gauges were allowed to run over, it is evidently necessary that British observers should be on the alert. It is not desirable to purchase any new gauge of which the capacity is less than four inches.

16. _Second Gauges._ It is often desirable that observers should have two gauges, and that one of them should be capable of holding eight inches of rain. One of the gauges should be registered daily, the other weekly or monthly, as preferred, but always on the 1st of each month. By this means a thorough check is kept on accidental errors in the entries, which is not the case if _both_ are read daily.

17. _Dew and Fog._ Small amounts of water are at times deposited in rain-gauges by fog and dew. They should be added to the amount of rainfall, because (1) "they tend to water the earth and nourish the streams," and not for that reason only, but (2) because in many cases the rain-gauges can only be visited monthly, and it would then obviously be impossible to separate the yield of snow, rain, &c.; therefore, for the sake of uniformity, all must be taken together.

18. _Doubtful Entries._ Whenever there is the least doubt respecting the accuracy of any observation, the entry should be marked with a ?, and the reason stated for its being placed there.

_Obs._ The height at which the rain-gauge is elevated from the ground is a matter of considerable moment. Thus, one observer found the fall of rain at York for twelve months (1833-1834) to be--at a height of 213 feet from the ground, 1496 inches; at 44 feet, 1985 inches; and on the ground, 2571 inches.

Later experimentalists have confirmed this curious fact. Thus, Colonel Warde found the following to be the relative rainfall at different periods for the four years extending from 1864 to 1867:

Inches.

On a level with the ground 107 At a height of 2 inches 105 " 6 " 101 " 1 foot 100 " 2 feet 099 " 3 " 098 " 5 " 096 " 10 " 095 " 20 " 094

One of the causes that have been a.s.signed for this singular phenomenon has been--the greater exposure in elevated situations of the rain to dispersive action of the wind, a surmise which derives some support from the circ.u.mstance, that when a rain-gauge is placed on a building, the roof of which is flat, of large area, and with few, if any, chimneys to disturb the air currents, an amount of rain is collected equalling that obtained on the surface of the ground.

=RAI'SINS.= _Syn._ DRIED GRAPES; UVae (B. P.). UVae SICCATae, UVA (Ph. L.), UVae Pa.s.sae (Ph. E. & D.), L. "The prepared fruit of _Vitis vinifera_"

(Linn.)--Ph. L. The grapes are allowed to ripen and dry on the vine. After being plucked and cleaned, they are dipped, for a few seconds, into a boiling lye of wood ashes and quicklime at 12 or 15 Baume, to every 4 galls. of which a handful of culinary salt and a pint of salad oil has been added; they are then exposed for 12 or 14 days in the sun to dry; they are, lastly, carefully garbled, and packed for exportation. The sweet, fleshy kinds of grapes are those selected for the above treatment; and, in general, their stalks are cut about one half through, or a ring of bark is removed, to hasten their maturation.

Raisins are nutritious, cooling, antiseptic, and, in general, laxative; the latter to a greater extent than the fresh fruit. There are many varieties found in commerce. Their uses as a dessert and culinary fruit, and in the manufacture of wine, &c., are well known, and are referred to elsewhere. See GRAPES, WINES, &c.

=RANCID'ITY.= The strong, sour flavour and odour which oleaginous bodies acquire by age and exposure to the air. For its prevention, see FATS, OILS (Fixed), &c.

=RAPE OIL.= See OILS (Fixed).

=RASH.= Erasmus Wilson notices four different affections, as included under this head:--

1. ST ANTHONY'S FIRE, or ERYSIPELAS, the severest of them all, already referred to.

2. NETTLE-RASH, or URTICARIA, characterised by its tingling and p.r.i.c.king pain, and its little white elevations on a reddish ground, like the wheals caused by the sting of a nettle. This efflorescence seldom stays many hours, and, sometimes, not even many minutes, in the same place, and is multiplied or reproduced whenever any part of the skin is scratched or even touched. No part of the body is exempt from it, and when many of them occur together, and continue for an hour or two, the parts are often considerably swelled, and the features temporarily disfigured. In many cases these eruptions continue to infest the skin, sometimes in one place, and sometimes in another, for one or two hours together, two or three times a day, or perhaps, for the greatest part of the twenty-four hours.

In some const.i.tutions this lasts only a few days; in others several months.

There are several varieties of nettle-rash or urticaria noticed by medical writers, among which URTICARIA FEBRILIS, PERSISTANS, and EVANIDA, are the princ.i.p.al.

The common cause of nettle-rash is some derangement of the digestive functions, arising either from the use of improper food or a disordered state of the nervous or other systems of the body. Lobsters, crabs, mussels, shrimps, dried fish, pork, cuc.u.mbers, mushrooms, and adulterated beer or porter, bear the character of frequently causing this affection.

In childhood it commonly arises from teething. Occasionally, in persons of peculiar idiosyncrasy, the most simple article of food, as almonds, nuts, and even milk, rice, and eggs, will produce this affection.

The treatment may consist of the administration of gentle saline aperients, and in severer cases a gentle emetic, followed by the copious use of acidulated diluent drinks, as weak lemon-juice-and-water, effervescing pota.s.sa-draughts, &c., and, when required, diaph.o.r.etics. The clothing should be light, but warm, and the itching, when severe, may be allayed by the application of a lotion of water to which a little vinegar or camphorated spirit has been added; the latter must, however, be employed with caution. A hot knee-bath is useful in drawing the affection from the face and upper part of the body. A 'compress,' wrung out of cold water until it ceases to drip, and kept in contact with the stomach by means of a dry bandage, has been recommended to relieve excessive irritation of the stomach and bowels. It has been stated that decoction of Virginian snake-root is particularly useful in relieving chronic urticaria.

3. RED-RASH, RED-BLOTCH, or FIERY SPOT, is commonly the consequence of disordered general health, of dyspepsia, and particularly, of females, of tight lacing. Sometimes it is slight and evanescent; at others it approaches in severity to the milder forms of erysipelas, there being much swelling and inflammation. Chaps, galls, excoriations, and chilblains are varieties of this disease produced by cold, excessive moisture, or friction. The treatment is similar to that of nettle-rash.

4. ROSE-RASH, FALSE MEASLES, or ROSEOLA, is an efflorescence, or rather a discoloration of a rose-red tint, in small irregular patches, without wheals or papulae, which spread over the surface of the body, and are ushered in by slight febrile symptoms. There are several varieties. The causes are the same as those which produce the preceding affections, and the treatment may be similar. In all of them strict attention to the diet, and a careful avoidance of cold applications, or exposure to cold, so as to cause a retrocession, are matters of the first moment.

=RASP'BERRY.= _Syn._ HINDBERRY. The fruit of _Rubus Idaeus_ (Linn.), a small shrub of the natural order _Rosaceae_. It is cooling, antis...o...b..tic, and mildly aperitive. It is frequently used to communicate a fine flavour to liqueurs, confectionery, wine, &c. See FRUITS and VEGETABLES.

Fresenius gives the following as the composition of raspberries:

CULTIVATED.

Wild Red. Red. White.

_Soluble Matter_-- Sugar 3597 4708 3703 Free acid (reduced to equivalent in malic acid) 1980 1356 1115 Alb.u.minous substances 0546 0544 0665 Pectous substances, &c. 1107 1746 1397 Ash 0270 0481 0318

_Insoluble Matter_-- Seeds } Skins, &c. } 8460 4106 4520 Pectose 0180 0502 0040