NAILS, MANUFACTURE OF. (_Clou_, Fr.; _Nagel_, Germ.)

The forging of nails was till of late years a handicraft operation, and

therefore belonged to a book of trades, rather than to a dictionary of

arts. But several combinations of machinery have been recently employed,

under the protection of patents, for making these useful implements,

with little or no aid of the human hand; and these deserve to be

noticed, on account both of their ingenuity and importance.

As nails are objects of prodigious consumption in building their

block-houses, the citizens of the United States very early turned their

mechanical genius to good account in the construction of various

machines for making them. So long since as the year 1810, it appears,

from the report of the secretary of their treasury, that they possessed

a machine which performed the cutting and heading at one operation, with

such rapidity that it could turn out upwards of 100 nails per minute.

“Twenty years ago,” says the secretary of the state of Massachusetts, in

that report, “some men, then unknown, and then in obscurity, began by

cutting slices out of old hoops, and, by a common vice griping these

pieces, headed them with several strokes of the hammer. By progressive

improvements, slitting-mills were built, and the shears and the heading

tools were perfected; yet much labour and expense were requisite to make

nails. In a little time Jacob Perkins, Jonathan Ellis, and a few others,

put into execution the thought of cutting and of heading nails by water

power; but, being more intent upon their machinery than upon their

pecuniary affairs, they were unable to prosecute the business. At

different times other men have spent fortunes in improvements, and it

may be said with truth that more than one million of dollars has been

expended; but at length these joint efforts are crowned with complete

success, and we are now able to manufacture, at about one-third of the

expense that wrought nails can be manufactured for, nails which are

superior to them for at least three-fourths of the purposes to which

nails are applied, and for most of those purposes they are full as good.

The machines made use of by Odiorne, those invented by Jonathan Ellis,

and a few others, present very fine specimens of American genius.

“To northern carpenters, it is well known that in almost all instances

it is unnecessary to bore a hole before driving a cut nail; all that is

requisite is, to place the cutting edge of the nail across the grain of

the wood; it is also true, that cut nails will hold better in the wood.

These qualities are, in some rough building works, worth twenty _per

cent._ of the value of the article, which is equal to the whole expense

of manufacturing. For sheathing and drawing, cut nails are full as good

as wrought nails; only in one respect are the best wrought nails a

little superior to cut nails, and that is where it is necessary they

should be clenched. The manufacture of cut nails was born in our

country, and has advanced, within its bosom, through all the various

stages of infancy to manhood; and no doubt we shall soon be able, by

receiving proper encouragement, to render them superior to wrought nails

in every particular.

“The principal business of rolling and slitting-mills, is rolling nail

plates; they also serve to make nail rods, hoops, tires, sheet iron, and

sheet copper. In this State we have not less than twelve.

“These mills could roll and slit 7000 tons of iron a year; they now, it

is presumed, roll and slit each year about 3500 tons, 2400 tons of

which, probably, are cut up into nails and brads, of such a quality that

they are good substitutes for hammered nails, and, in fact, have the

preference with most people, for the following reasons; viz., on account

of the sharp corner and true taper with which cut nails are formed; they

may be driven into harder wood without bending or breaking, or hazard of

splitting the wood, by which the labour of boring is saved, the nail one

way being of the same breadth or thickness from head to point.”

Since the year 1820, the following patents have been obtained in England

for making nails; many of them of American origin:--

_Alexander Law_, September, 1821, for nails and bolts for ships’

fastenings, made in a twisted form, by hand labour.

_Glascott and Mitchell_, December, 1823, for ship nails with rounded

heads, by hand labour.

_Wilks and Ecroyd_, November, 1825, for an engine for cutting wedge-form

pieces from plates.

_Ledsom and Jones_, December 11, 1827, for machinery for cutting brads

and sprigs from plates; it does not form heads.

The first nail apparatus to which I shall particularly advert, is due to

Dr. Church; it was patented in his absence by his correspondent, Mr.

Thomas Tyndall, of Birmingham, in December, 1827. It consists of two

parts; the first is a mode of forming nails, and the shafts of screws,

by pinching or pressing ignited rods of iron between indented rollers;

the second produces the threads on the shafts of the screws previously

pressed. The metallic rods, by being passed between a pair of rollers,

are rudely shaped, and then cut asunder between a pair of shears; after

which they are pointed and headed, or otherwise brought to their

finished forms, by the agency of dies placed in a revolving cylinder.

The several parts of the mechanism are worked by toothed wheels, cams,

and levers. The second part of Dr. Church’s invention consists of a

mechanism for cutting the threads of screws to any degree of obliquity

or form.[35]

[35] For further details, see Newton’s Journal, 2nd series, vol. iii.

p. 184.

Mr. L. W. Wright’s (American) apparatus should have been mentioned

before the preceding, as the patent for it was sealed in March of the

same year; though an amended patent was obtained in September, 1828. Its

object was to form metal screws for wood. I have seen the machinery, but

consider it much too complex to be described in the present work.

Mr. Edward Hancorne, of Skinner street, London, nail manufacturer,

obtained a patent in October, 1828 for a nail-making machine, of which a

brief description may give my readers a conception of this kind of

manufacture. Its principles are similar to those of Dr. Church’s more

elaborate apparatus.

[Illustration: 749]

The rods or bars having been prepared in the usual way, either by

rolling or hammering, or by cutting from sheets or plates of iron,

called slitting, are then to be made redhot, and in that state passed

through the following machine, whereby they are at once cut into

suitable lengths, pressed into wedge forms for pointing at the one end,

and stamped at the other end to produce the head. A longitudinal view of

the machine is shown in _fig._ 749. A strong iron frame-work, of which

one side is shown at _a a_, supports the whole of the mechanism. _b_ is

a table capable of sliding to and fro horizontally. Upon this table are

the clamps, which lay hold of the sides of the rod as it advances; as

also the shears which cut the rod into nail lengths.

These clamps or holders consist of a fixed piece and a movable piece;

the latter being brought into action by a lever. The rod or bar of iron

shown at _c_, having been made redhot, is introduced into the machine by

sliding it forward upon the table _b_, when the table is in its most

advanced position; rotatory motion is then given to the crank shaft _d_,

by means of a band passing round the rigger pulley _e_, which causes the

table _b_ to be drawn back by the crank rod _f_: and as the table

recedes, the horizontal lever is acted upon, which closes the clamps. By

these means the clamps take fast hold of the sides of the heated rod,

and draw it forward, when the movable chap of the shears, also acted

upon by a lever, slides laterally, and cuts off the end of the rod held

by the clamps: the piece thus separated is destined to form one nail.

Suppose that the nail placed at _g_, having been thus brought into the

machine and cut off, is held between clamps, which press it sideways

(these clamps are not visible in this view); in this state it is ready

to be headed and pointed.

The _header_ is a steel die _h_, which is to be pressed up against the

end of the nail by a cam _i_, upon the crank-shaft; which cam, at this

period of the operation, acts against the end of a rod _k_, forming a

continuation of the die _h_, and forces up the die, thus compressing the

metal into the shape of a nail-head.

The _pointing_ is performed by two rolling snail pieces or spirals _l_,

_l_. These pieces are somewhat broader than the breadth of the nail;

they turn upon axles in the side frames. As the table _b_ advances, the

racks _m_, on the edge of this table, take into the toothed segments

_n_, _n_, upon the axles of the spirals, and cause them to turn round.

These spirals pinch the nail at first close under its head with very

little force; but as they turn round, the longer radius of the spiral

comes into operation upon the nail, so as to press its substance very

strongly, and squeeze it into a wedge form. Thus the nail is completed,

and is immediately discharged from the clamps or holders. The carriage

is then again by the rotation of the crank-shaft, which brings another

portion of the rod _c_ forward, cuts it off, and then forms it into a

nail.

_Richard Prosser_, July, 1831, for making tacks for ornamental

furniture, by soldering or wedging the spike into the head. This also is

the invention of Dr. Church.

_Dr. William Church_, February, 1832, for improvements in machinery for

making nails. These consist, first, in apparatus for forming rods, bars,

or plates of iron, or other metals; secondly, in apparatus for

converting the rods, &c., into nails; thirdly, in improvements upon

Prosser’s patent. The machinery consists in laminating rollers, and

compressing dies.

The method of forming the rods from which the nails are to be made, is

very advantageous. It consists in passing the bar or plate iron through

pressing rollers, which have indentations upon the peripheries of one or

both of them, so as to form the bar or plate into the required shape for

the rods, which may be afterwards separated into rods of any desired

breadth, by common slitting rollers.

The principal object of rolling the rods into these wedge forms, is to

measure out a quantity of metal duly proportioned to the required

thickness or strength of the nail in its several parts; which quantity

corresponds to the indentations of the rollers.

_Thomas John Fuller_, February 27, 1834, for an improved apparatus for

making square-pointed, and also flat-pointed nails. He claims as his

invention, the application of vertical and horizontal hammers (mounted

in his machine) combined for the purpose of tapering and forming the

points of the nails; which, being made to act alternately, resemble hand

work, and are therefore not so apt to injure the fibrous texture of the

iron, he imagines, as the rolling machinery is. He finishes the points

by rollers.

_Miles Berry_, February 19, 1834, for machinery for forming metal into

bolts, rivets, nails and other articles; being a communication from a

foreigner residing abroad. He employs in his machine holding chaps,

heading dies, toggle joints, cams, &c., mechanisms apparently skilfully

contrived, but too complex for admission under the article _nail_ in

this volume.

_William Southwood Stocker_, July, 1836. This is a machine apparently of

American parentage, as it has the same set of features as the old

American mechanisms of Perkins and Dyer, at the Britannia Nailworks,

Birmingham, and all the other American machines since described, for

pressing metal into the forms of nails, pins, screw-shafts, rivets, &c.;

for example, it possesses pressers or hammers for squeezing the rods of

metal, and forming the shanks, which are all worked by a rotatory

action; cutters for separating the appropriate lengths, and dies for

forming the heads by compression, also actuated by revolving cams or

cranks.

Mr. Stocker intends, in fact, to effect the same sorts of operations by

automatic mechanisms as are usually performed by the hands of a

nail-maker with his hammer and anvil; viz., the shaping of a nail from a

heated rod of iron, cutting it off at the proper length, and then

compressing the end of the metal into the form of the head. His machine

may be said to consist of two parts, connected in the same frame; the

one for shaping the shank of the nail, the other for cutting it off and

heading it. The frame consists of a strong table to bear the machinery.

Two pairs of hammers, formed as levers, the one pair made to approach

each other by horizontal movements, the other pair by vertical

movements, are the implements by which a portion at the end of a redhot

rod of iron is beaten or pressed into the wedge-like shape of the shaft

of a nail. This having been done, and the rod being still hot, is

withdrawn from the beaters, and placed in the other part of the machine,

consisting of a pair of jaws like those of a vice, which pinch the shank

of the nail and hold it fast. A cutter upon the side of a wheel now

comes round, and, by acting as the moving chap of a pair of shears, cuts

the nail off from the rod. The nail shank being still firmly held in the

jaws of the vice, with a portion of its end projecting outwardly, the

heading die is slidden laterally until it comes opposite to the end of

the nail; the dye is then projected forward with great force, for the

purpose of what is termed upsetting the metal at the projecting end of

the nail, and thereby blocking out the head.

A main shaft, driven by a band and rigger as usual, brings, as it

revolves, a cam into operation upon a lever which carries a double

inclined plane or wedge in its front or acting part. This wedge being by

the rotatory cam projected forwards between the tails of one of the

pairs of hammers, causes the faces of these hammers to approach each

other, and to beat or press the redhot iron introduced between them, so

as to flatten it upon two opposite sides. The rotatory cam passing

round, the wedge lever is relieved, when springs instantly throw back

the hammers; another cam and wedge-lever now brings the second pair of

hammers to act upon the other two sides of the nail in a similar way.

This is repeated several times, until the end of the redhot iron rod,

gradually advanced by the hands of the workman, has assumed the desired

form, that is, has received the bevel and point of the intended nail.

The rod is then withdrawn from between the hammers, and in its heated

state is introduced between the jaws of the holders, for cutting off and

finishing the nail. A bevel pinion upon the end of the main shaft, takes

into and drives a wheel upon a transverse shaft, which carries a cam

that works the lever of the holding jaws. The end of the rod being so

held in the jaws or vice, a cutter at the side of a wheel upon the

transverse shaft separates, as it revolves, the nail from the end of the

rod, leaving the nail firmly held by the jaws. By means of a cam, the

heading die is now slidden laterally opposite to the end of the nail in

the holding jaws, and by another cam, upon the main shaft, the die is

forced forward, which compresses the end of the nail, and spreads out

the nail into the form of a head. As the main shaft continues to

revolve, the cams pass away, and allow the spring to throw the jaws of

the vice open, when the nails fall out; but to guard against the chance

of a nail sticking in the jaws, a picker is provided, which pushes the

nail out as soon as it is finished.

In order to produce round shafts, as for screw blanks, bolts, or rivets,

the faces of the hammers, and the dies for heading, must be made with

suitable concavities.

In 1835, 5,180, and in 1836, 5,580 tons of iron nails were exported from

the United Kingdom.

NANKIN, is a peculiarly coloured cotton cloth, originally manufactured

in the above named antient capital of China, from a native cotton of a

brown yellow hue. Nankin cloth has been long imitated in perfection by

our own manufacturers; and is now exported in considerable quantities

from England to Canton. The following is the process for dyeing calico a

nankin colour.

1. Take 300 pounds of cotton yarn in hanks, being the quantity which

four workmen can dye in a day. The yarn for the warp may be about No.

27’s, and that for the weft 23’s or 24’s.

2. For _aluming_ that quantity, take 10 pounds of saturated alum, free

from iron (see MORDANT); divide this into two portions; dissolve the

first by itself in hot water, so as to form a solution, of spec. grav.

1° Baumé. The second portion is to be reserved for the galling bath.

3. _Galling_, is given with about 80 pounds of oak bark finely ground.

This bark may serve for two quantities, if it be applied a little longer

the second time.

4. Take 30 pounds of fresh slaked quicklime, and form with it a large

bath of lime-water.

5. _Nitro-muriate of tin._ For the last bath, 10 or 12 pounds of

solution of tin are used, which is prepared as follows:

Take 10 pounds of strong nitric acid, and dilute with pure water till

its specific gravity be 26° B. Dissolve in it 4633 grains (10-1/2 oz.

avoird.) of sal ammoniac, and 3 oz. of nitre. Into this solvent,

contained in a bottle set in cold water, introduce successively, in very

small portions, 28 ounces of grain-tin granulated. This solution, when

made, must be kept in a well stoppered bottle.

Three coppers are required, one round, about five feet in diameter, and

32 inches deep, for scouring the cotton; 2. two rectangular coppers

tinned inside, each 5 feet long and 20 inches deep. Two boxes or

cisterns of white wood are to be provided, the one for the lime-water

bath, and the other for the solution of tin, each about 7 feet long, 32

inches wide, and 14 inches deep; they are set upon a platform 28 inches

high. In the middle between these two chests, a plank is fixed, mounted

with twenty-two pegs for wringing the hanks upon, as they are taken out

of the bath.

6. _Aluming._ After the cotton yarn has been scoured with water, in the

round copper, by being boiled in successive portions of 100 pounds, it

must be winced in one of the square tinned coppers, containing two

pounds of alum dissolved in 96 gallons of water, at a temperature of

165° F. It is to be then drained over the copper, exposed for some time

upon the grass, rinsed in clear water, and wrung.

7. The _galling_. Having filled four-fifths of the second square copper

with water, 40 pounds of ground oak bark are to be introduced, tied up

in a bag of open canvas, and boiled for two hours. The bag being

withdrawn, the cotton yarn is to be winced through the boiling tan bath

for a quarter of an hour. While the yarn is set to drain above the bath,

28 ounces of alum are to be dissolved in it, and the yarn being once

more winced through it for a quarter of an hour, is then taken out,

drained, wrung, and exposed to the air. It has now acquired a deep but

rather dull yellowish colour, and is ready without washing for the next

process. Bablah may be substituted for oak bark with advantage.

8. The _liming_. Into the cistern filled with fresh made lime-water, the

hanks of cotton yarn suspended upon a series of wooden rods, are to be

dipped freely three times in rapid succession; then each hank is to be

separately moved by hand through the lime bath, till the desired

carmelite shade appear. A weak soda lye may be used instead of lime

water.

9. The _brightening_, is given by passing the above hanks, after

squeezing, rinsing, and airing them, through a dilute bath of solution

of tin. The colour thus produced is said to resemble perfectly the

nankin of China.

Another kind of nankeen colour is given by oxide of iron, precipitated

upon the fibre of the cloth, from a solution of the sulphate, by a

solution of soda. See CALICO-PRINTING.

NAPLES YELLOW (_Jaune minéral_, Fr.; _Neapelgelb_, Germ.); is a fine

yellow pigment, called _giallolino_, in Italy, where it has been long

prepared by a secret process; for few of the recipes which have been

published produce a good colour. It is employed not only in oil

painting, but also for porcelain and enamel. It has a fresh, brilliant,

rich hue, but is apt to be very unequal in different samples.

The following prescription has been confidently recommended. Twelve

parts of metallic antimony are to be calcined in a reverberatory

furnace, along with eight parts of red lead, and four parts of oxide of

zinc. These mixed oxides being well rubbed together, are to be fused;

and the fused mass is to be triturated and elutriated into a fine

powder. Chromate of lead has in a great measure superseded Naples

yellow.

NAPHTHA, or ROCK-OIL (_Huile pétrole_, Fr.; _Steinöl_, Germ.); the

Seneca oil of North America, is an ethereous or volatile oil, which is

generated within the crust of the earth, and issues in many different

localities. The colourless kind, called naphtha, occurs at Baku, near

the Caspian Sea, where the vapours which it exhales are kindled, and the

flame is applied to domestic and other economical purposes. Wells are

also dug in that neighbourhood, in which the naphtha is collected.

Similar petroleum wells exist in the territory of the Birmans, at

Yananghoung, upon the river Erawaddy, 80 hours’ journey north-east of

Pegu, where no less than 520 such springs issue from a pale blue clay,

soaked with oil, which rests upon roofing slate. Under the slate is

coal containing much pyrites. Each spring yields annually 173 casks of

950 pounds each. Petroleum is also found at Amiano in the duchy of

Parma, at Saint Zibio in the grand duchy of Modena, at Neufchatel in

Switzerland, at Clermont in France, upon some points of the banks of the

Iser, at Gabian, a village near Bezières, at Tegernsee in Bavaria, at

Val di Noto in Sicily, in Zante, Gallicia, Wallachia, Trinidad,

Barbadoes, the United States, Rangoon, near Ava, &c. What is found in

the market comes mostly from Trinidad. The city of Parma is lighted with

naphtha.

The Persian rock-oil is colourless, limpid, very fluid, of a penetrating

odour, a hot taste, and a specific gravity of 0·753; it is said to boil

at 160° F. The common petroleum has a reddish-yellow colour, which

appears blue by reflected light, is transparent, has a spec. grav. of

0·836, and contains, according to Unverdorben, several oils of different

degrees of volatility, a little oleine and stearine, resin, with a brown

indifferent substance held in solution. By repeated rectifications its

density may be reduced to 0·758 at 60° F. Native naphtha, of specific

gravity 0·749, is said by some to boil at 201° F. The condensed vapour

consists of 85·05 carbon, and 14·30 hydrogen.

The naphtha procured by distilling the coal oil of the gas works, is of

specific gravity 0·857, boils at 316° F., and consists of, carbon 83·04,

hydrogen 12·31, and oxygen 4·65, by my experiments.

Rock-oil is very inflammable; its vapour forms with oxygen gas a mixture

which violently detonates, and produces water and carbonic acid gas. It

does not unite with water, but it imparts a peculiar smell and taste to

it; it combines in all proportions with strong alcohol, with ether and

oils, both essential and unctuous; it dissolves sulphur, phosphorus,

iodine, camphor, most of the resins, wax, fats, and softens caoutchouc

into a glairy varnish. When adulterated with oil of turpentine, it

becomes thick and reddish brown, on being agitated in contact with

strong sulphuric acid. A very fine black pigment may be prepared from

the soot of petroleum lamps.

NAPHTHALINE, is a peculiar white crystallizable substance, which may be

extracted by distillation from coal tar. It has a pungent aromatic smell

and taste, and a specific gravity of 1·048. It is a solid bicarburet of

hydrogen, consisting, by my experiments, of 92·9 of carbon, and 7·1 of

hydrogen. It has not been applied to any use.

NATRON, is the name of the native sesquicarbonate of soda, which occurs

in Egypt, in the west of the Delta; also in the neighbourhood of Fessan,

in the province of Sukena in Northern Africa, where it exists under the

name of _Trona_, crystallized along with sulphate of soda; near Smyrna,

in Tartary, Siberia, Hungary, Hindostan, and Mexico. In the last

country, there are several natron lakes, a little to the north of

Zucatecas, as well as in many other provinces. In Columbia, 48 miles

from Merida, native mineral natron is dug up from the bottom of lakes in

large quantities, under the name of _Urao_.

According to Laugier, the Egyptian natron consists of carbonate of soda

22·44, sulphate of soda 18·35, muriate of soda 38·64, water 14·0,

insoluble matter 6·0. Trona is composed of carbonate of soda 65·75,

sulphate of soda 7·65, muriate of soda 2·63, water 24, insoluble matter

1. The sesquicarbonate may be artificially prepared by boiling for a

short time a solution of the bicarbonate.

NEALING. See ANNEALING.

NEB-NEB, is the East Indian name of Bablah.

NEEDLE MANUFACTURE. When we consider the simplicity, smallness, and

moderate price of a needle, we would be naturally led to suppose that

this little instrument requires neither much labour nor complicated

manipulations in its construction; but when we learn that every sewing

needle, however inconsiderable its size, passes through the hands of 120

different operatives, before it is ready for sale, we cannot fail to be

surprised.

The best steel, reduced by a wire-drawing machine to the suitable

diameter, is the material of which needles are formed. It is brought in

bundles to the needle factory, and carefully examined. For this purpose,

the ends of a few wires in each bundle are cut off, ignited, and

hardened by plunging them into cold water. They are now snapped between

the fingers, in order to judge of their quality; the bundles belonging

to the most brittle wires are set aside, to be employed in making a

peculiar kind of needles.

After the quality of the steel wire has been properly ascertained, it is

calibred by means of a gauge, to see if it be equally thick and round

throughout, for which purpose merely some of the coils of the bundle of

wires are tried. Those that are too thick are returned to the

wire-drawer, or set apart for another size of needles.

[Illustration: 750 751]

The first operation, properly speaking, of the needle factory, is

unwinding the bundles of wires. With this view the operative places the

coil upon a somewhat conical reel, _fig._ 750., whereon he may fix it at

a height proportioned to its diameter. The wire is wound off upon a

wheel B, formed of eight equal arms, placed at equal distances round a

nave, which is supported by a polished round axle of iron, made fast to

a strong upright C, fixed to the floor of the workshop. Each of the arms

is 54 inches long; and one of them D, consists of two parts; of an

upper part, which bears the cross bar E, to which the wire is applied;

and of an under part, connected with the nave. The part E slides in a

slot in the fixed part F, and is made fast to it by a peg at a proper

height for placing the ends of all the spokes in the circumference of a

circle. This arrangement is necessary, to permit the wire to be readily

taken off the reel, after being wound tight round its eight branches.

The peg is then removed, the branch pushed down, and the coil of wire

released. _Fig._ 751. shows the wheel in profile. It is driven by the

winch-handle G.

[Illustration: 752 753]

The new made coil is cut in two points diametrically opposite, either by

hand shears, of which one of the branches is fixed in a block by a bolt

and a nut, as shown in _fig._ 752., or by means of the mechanical

shears, represented in _fig._ 753. The crank A is moved by a hydraulic

wheel, or steam power, and rises and falls alternately. The extremity of

this crank enters into a mortise cut in the arm B of a bent lever B G C,

and is made fast to it by a bolt. An iron rod D F, hinged at one of its

extremities to the end of the arm C, and at the other to the tail of the

shears or chisel E, forces it to open and shut alternately. The

operative placed upon the floor under F presents the coil to the action

of the shears, which cut it into two bundles, composed each of 90 or 100

wires, upwards of 8 feet long. The chisel strikes 21 blows in the

minute.

These bundles are afterwards cut with the same shears into the desired

needle lengths, these being regulated by the diameter. For this purpose

the wires are put into a semi-cylinder of the proper length, with their

ends at the bottom of it, and are all cut across by this gauge. The

wires, thus cut, are deposited into a box placed alongside of the

workman.

[Illustration: 754 755 756 757]

Two successive incisions are required to cut 100 wires, the third is

lost; hence the shears, striking 21 blows in a minute, cut in 10 hours

fully 400,000 ends of steel wire, which produce more than 800,000

needles. The wires thus cut are more or less bent, and require to be

straightened. This operation is executed with great promptitude, by

means of an appropriate instrument. In two strong iron rings A B, _fig._

754., of which one is shown in front view at C, 5000 or 6000 wires,

closely packed together, are put; and the bundle is placed upon a flat

smooth bench L M, _fig._ 757., covered with a cast-iron plate D E, in

which there are two grooves of sufficient depth for receiving the two

ring bundles of wire, or two openings like the rule F, _fig._ 757., upon

which is placed the open iron rule F, shown in front in _fig._ 756. upon

a greater scale. The two rings must be carefully set in the intervals of

the rule. By making this rule come and go five or six times with such

pressure upon the bundles of wires as causes it to turn upon its axis,

all the wires are straightened almost instantaneously.

The construction of the machine, represented in _fig._ 757., may require

explanation. It consists of a frame in the form of a table, of which L M

is the top; the cast-iron plate D E is inserted solidly into it. Above

the table, seen in _fig._ 755. in plan, there are two uprights C H, to

support the cross bar A A, which is held in forks cut out in the top of

each of the two uprights. This cross bar A A, enters tightly into a

mortise cut in the swing piece N, at the point N, where it is fixed by a

strong pin, so that the horizontal traverse communicated to the cross

bar A A affects at the same time the swing piece N. At the bottom of

this piece is fixed, as shown in the figure, the open rule F, seen upon

a greater scale in _fig._ 756.

When the workman wishes to introduce the bundle B, he raises, by means

of two chains I K, _fig._ 757., and the lever G O, the swing piece and

the cross bar. For this purpose he draws down the chain I; and when he

has placed the bundle properly, so that the two rings enter into the

groove E D, _fig._ 755., he allows the swing piece to fall back, so that

the same rings enter the open clefts of the rule F; he then seizes one

of the projecting arms of the cross bar A, alternately pulling and

pushing it in the horizontal direction, whereby he effects, as already

stated, the straightening of the wires.

[Illustration: 758]

The wires are now taken to the pointing-tools, which usually consist of

about 30 grindstones arranged in two rows, driven by a water-wheel. Each

stone is about 18 inches in diameter, and 4 inches thick. As they

revolve with great velocity, and are liable to fly in pieces, they are

partially encased by iron plates, having a proper slit in them to admit

of the application of the wires. The workman seated in front of the

grindstone, seizes 50 or 60 wires between the thumb and forefinger of

his right hand, and directs one end of the bundle to the stone. By means

of a bit of stout leather called a thumb-piece, of which A, _fig._ 758.,

represents the profile, and B the plan, the workman presses the wires,

and turns them about with his forefinger, giving them such a rotatory

motion as to make their points conical. This operation, which is called

_roughing down_, is dry grinding; because, if water were made use of,

the points of the needles would be rapidly rusted. It has been observed

long ago, that the siliceous and steel dust thrown off by the stones,

was injurious to the eyes and lungs of the grinders; and many methods

have been proposed for preventing its bad effects. The machine invented

for this purpose by Mr. Prior, for which the Society of Arts voted a

premium, deserves to be generally known.

[Illustration: 759]

A A, _fig._ 759., is the fly-wheel of an ordinary lathe, round which the

endless cord B B passes, and embraces the pulley C, mounted upon the

axle of the grindstone D. The flywheel is supported by a strong frame E

E, and may be turned by a winch-handle, as usual, or by mechanical

power. In the needle factories, the pointing-shops are in general very

large, and contain several grindstones running on the same long

horizontal shaft, placed near the floor of the apartment, and driven by

water or steam power. One of the extremities of the shaft of the wheel A

has a kneed or bent winch F, which by means of an intermediate crank G

G, sets in action a double bellows H I, with a continuous blast,

consisting of the air feeder H below, and the air regulator I above. The

first is composed of two flaps, one of them _a a_, being fast and

attached to the floor, and the other _e e_, moving with a hinge-joint;

both being joined by strong leather nailed to their edges. This flap has

a tail _g_, of which the end is forked to receive the end of the crank

G. Both flaps are perforated with openings furnished with valves for the

admission of the air, which is thence driven into a horizontal pipe K,

placed beneath the floor of the workshop, and may be afterwards directed

in an uninterrupted blast upon the grindstone, by means of the tin tubes

N O O, which embrace it, and have longitudinal slits in them. A brass

socket is supposed to be fixed upon the ground; it communicates with the

pipe K, by means of a small copper tube, into which one of the

extremities of the pipe N is fitted; the other is supported by the point

of a screw Q, and moves round it as a pivot, so as to allow the two

upright branches O O, to be placed at the same distance from the

grindstone. These branches are soldered to the horizontal pipe N, and

connected at their top by the tube P.

The wind which escapes through the slits of these pipes, blows upon the

grindstone, and carries off its dust into a conduit R, _fig._ 759.,

which may be extended to S, beyond the wall of the building, or bent at

right angles, as at T, to receive the conduits of the other grindstones

of the factory.

A safety valve J, placed in an orifice formed in the regulator flap I,

is kept shut by a spiral spring of strong iron wire. It opens to allow

the superfluous air to escape, when, by the rising of the bellows, the

tail L presses upon a small piece of wood, and thereby prevents their

being injured.

[Illustration: 760]

The wires thus pointed at both ends are transferred to the first

workshop, and cut in two, to form two needles, so that all of one

quality may be of equal length. For each sort a small instrument, _fig._

760., is employed, being a copper plate nearly square, having a turned

up edge only upon two of its sides; the one of which is intended to

receive all the points, and the other to resist the pressure of the

shears. In this small tool a certain number of wires are put with their

points in contact with the border, and they are cut together flush with

the plate by means of the shears, _fig._ 752., which are moved by the

knee of the workman. The remainder of the wires are then laid upon the

same copper or brass tool, and are cut also even; there being a trifling

waste in this operation. The pieces of wire out of which two needles are

formed, are always left a little too long, as the pointer can never hit

exact uniformity in his work.

These pointed wires are laid parallel to each other in little wooden

boxes, and transferred to the head-flattener. This workman, seated at a

table with a block of steel before him, about 3 inches cube, seizes in

his left hand 20 or 25 needles, between his finger and thumb, spreading

them out like a fan, with the points under the thumb, and the heads

projecting; he lays these heads upon the steel block, and with a small

flat-faced hammer strikes successive blows upon all the heads, so as to

flatten each in an instant. He then arranges them in a box with the

points turned the same way.

The flatted heads have become hardened by the blow of the hammer; when

annealed by heating and slow cooling, they are handed to the _piercer_.

This is commonly a child, who laying the head upon a block of steel, and

applying the point of a small punch to it, pierces the eye with a smart

tap of a hammer, applied first upon the one side, and then exactly

opposite upon the other.

Another child trims the eyes, which he does by laying the needle upon a

lump of lead, and driving a proper punch through its eye; then laying it

sidewise upon a flat piece of steel, with the punch sticking in it, he

gives it a tap on each side with his hammer, and causes the eye to take

the shape of the punch. The operation of piercing and trimming the eyes,

is performed by clever children with astonishing rapidity; who become so

dexterous as to pierce with their punch a human hair, and thread it with

another, for the amusement of visitors.

[Illustration: 761]

The next operative makes the groove at the eye, and rounds the head. He

fixes the needle in pincers, _fig._ 761., so that the eye corresponds to

their flat side; he then rests the head of the needle in an angular

groove, cut in a piece of hard wood fixed in a vice, with the eye in an

upright position. He now forms the groove with a single stroke of a

small file, dexterously applied, first to the one side of the needle,

and then to the other. He next rounds and smooths the head with a small

flat file. Having finished, he opens the pincers, throws the needle upon

the bench, and puts another in its place. A still more expeditious

method of making the grooves and finishing the heads has been long used

in most English factories. A small ram is so mounted as to be made to

rise and fall by a pedal lever, so that the child works the tool with

his foot; in the same way as the heads of pins are fixed. A small die of

tempered steel bears the form of the one channel or groove, another

similar die, that of the other, both being in relief; these being worked

by the lever pedal, finish the grooving of the eye at a single blow, by

striking against each other, with the head of the needle between them.

The whole of the needles thus prepared are thrown pell-mell into a sort

of drawer or box, in which they are by a few dexterous jerks of the

workman’s hand made to arrange themselves parallel to each other.

The needles are now ready for the tempering; for which purpose they are

weighed out in quantities of about 30 pounds, which contain from 250,000

to 500,000 needles, and are carried in boxes to the _temperer_. He

arranges these upon sheet-iron plates, about 10 inches long, and 5

inches broad, having borders only upon the two longer sides. These

plates are heated in a proper furnace to bright redness for the larger

needles, and to a less intense degree for the smaller; they are taken

out, and inverted smartly over a cistern of water, so that all the

needles may be immersed at the same moment, yet distinct from one

another. The water being run off from the cistern, the needles are

removed, and arranged by agitation in a box, as above described. Instead

of heating the needles in a furnace, some manufacturers heat them by

means of a bath of melted lead in a state of ignition.

After being suddenly plunged in the cold water, they are very hard and

excessively brittle. The following mode of tempering them is practised

at Neustadt. The needles are thrown into a sort of frying-pan along with

a quantity of grease. The pan being placed on the fire, the fatty matter

soon inflames, and is allowed to burn out; the needles are now found to

be sufficiently well tempered. They must, however, be re-adjusted upon

the steel anvil, because many of them get twisted in the hardening and

tempering.

[Illustration: 762 763]

_Polishing_ is the longest, and not the least expensive process in the

needle manufacture. This is done upon bundles containing 500,000

needles; and the same machine under the guidance of one man, polishes

from 20 to 30 bundles at a time; either by water or steam power. The

needles are rolled up in canvas along with some quartzose sand

interstratified between their layers, and the mixture is besmeared with

rape-seed oil. _Fig._ 762. represents one of the rolls or packets of

needles 12 inches long, strongly bound with cords. These packets are

exposed to the to-and-fro pressure of wooden tables, by which they are

rolled about, with the effect of causing every needle in the bundle to

rub against its fellow, and against the siliceous matter, or emery,

enclosed in the bag. _Fig._ 763. represents an improved table for

polishing the needles by attrition-bags. The lower table M M is movable,

whereas in the old constructions it was fixed; the table C has merely a

vertical motion, of pressure upon the bundles, whereas formerly it had

both a vertical and horizontal motion. Several bundles may obviously be

polished at once in the present machine. The table M M may be of any

length that is required, and from 24 to 27 inches broad; resting upon

the wooden rollers B, B, B, placed at suitable distances, it receives a

horizontal motion, either by hand or other convenient power; the packets

of needles A, A, A, are laid upon it, and over them the tables C, C, C,

which are lifted by means of the chains K, K, K, and the levers L, L, L,

in order to allow the needles to be introduced or removed. The see-saw

motion forces the _rouleaux_ to turn upon their own axes, and thereby

creates such attrition among their contents as to polish them. The

workman has merely to distribute these rolls upon the table M, in a

direction perpendicular to that in which the table moves; and whenever

one of them gets displaced, he sets it right, lifting by the help of the

chain the loaded table. The table makes about 20 horizontal double

vibrations in the minute; whereby each bundle, running over 24 inches

each time, passes through 40 feet per minute, or 800 yards in the hour.

[Illustration: 764]

_Scouring by the cask._ After being worked during 18 or 20 hours under

the tables, the needles are taken out of the packets, and put into

wooden bowls, where they are mixed with sawdust to absorb the black

grease upon their surfaces. They are next introduced into a cask, _fig._

764., and a workman seizing the winch P, turns it round a little; he now

puts in some more sawdust at the door, A, B, which is then shut by the

clasps G G, and continues the rotation till the needles be quite clean

and clear in their eyes; which he ascertains by taking out a sample of

them from time to time.

_Winnowing_ is the next process, by means of a mechanical ventilator

similar to that by which corn is winnowed. The sawdust is blown away,

and the grinding powder is separated from the needles, which remain

apart clean and bright.

The needles are in the next place arranged in order, by being shaken, as

above described, in a small somewhat concave iron tray. After being thus

laid parallel to each other, they are shaken up against the end of the

tray, and accumulated in a nearly upright position, so that they can be

seized in a heap and removed in a body upon a pallet knife, with the

help of the forefinger.

[Illustration: 765 766]

The preceding five operations, of making up the _rouleaux_, rolling them

under the tables, scouring the needles in the cask, winnowing, and

arranging them, are repeated ten times in succession, in manufacturing

the best articles; the only variation being in the first process.

Originally the bundles of needles are formed with alternate layers of

siliceous schistus and needles; but after the seventh time, bran freed

from flour by sifting is substituted for the schistus. The subsequent

four processes are, however, repeated as described. It has been found in

England, that emery powder mixed with quartz and mica or pounded

granite, is preferable to every thing else for polishing needles at

first by attrition in the bags; at the second and following operations,

emery mixed with olive oil is used, up to the eighth and ninth, for

which putty or oxide of tin with oil is substituted for the emery; at

the tenth the putty is used with very little oil; and lastly bran is

employed to give a finish. In this mode of operating, the needles are

_scoured_ in the copper cask shown in elevation _fig._ 765., and in

section _fig._ 766. The inner surface of this cask is studded with

points to increase the friction among the needles; and a quantity of hot

soap suds is repeatedly introduced to wash them clean. The cask must be

slowly turned upon its axis, for fear of injuring the mass of needles

which it contains. They are finally dried in the wooden cask by

attrition with sawdust; then wiped individually with a linen rag or soft

leather; when the damaged ones are thrown aside.

[Illustration: 767 768]

_Sorting of the needles._ This operation is performed in a dry upper

chamber, kept free from damp by proper stoves. Here all the points are

first laid the same way; and the needles are then picked out from each

other in the order of their polish. The sorting is effected with

surprising facility. The workman places 2000 or 3000 needles in an iron

ring, _fig._ 767., two inches in diameter, and sets all their heads in

one plane; then on looking carefully at their points, he easily

recognises the broken ones; and by means of a small hook fixed in a

wooden handle, _fig._ 768., he lays hold of the broken needle, and turns

it out. These defective needles pass into the hands of another workman,

who points them anew upon a grindstone, and they form articles of

inferior value. The needles which have got bent in the polishing must

now be straightened. The whole are finally arranged exactly according to

their lengths by the tact of the finger and thumb of the sorter.

The needles are divided into quantities for packing in blue papers, by

putting into a small balance the equivalent weight of 100 needles, and

so measuring them out without the trouble of counting them individually.

[Illustration: 769]

The _bluer_ receives these packets, and taking 25 of their needles at a

time between the forefinger and thumb, he presses their points against a

very small hone-stone of compact micaceous schist, mounted in a little

lathe, as shown in _fig._ 769., he turns them briskly round, giving the

points a bluish cast, while he polishes and improves them. This partial

polish is in the direction of the axis; that of the rest of the needle

is transverse, which distinguishes the boundaries of the two. The little

hone-stone is not cylindrical, but quadrangular, so that it strikes

successive blows with its corners upon the needles as it revolves,

producing the effect of filing lengthwise. Whenever these angles seem to

be blunted, they are set again by the _bluer_.

It is easy to distinguish good English needles from spurious imitations;

because the former have their axis coincident with their points, which

is readily observed by turning them round between the finger and thumb.

The construction of a needle requires, as already stated, about 120

operations; but they are rapidly and uninterruptedly successive. A child

can _trim_ the eyes of 4000 needles per hour.

When we survey a manufacture of this kind, we cannot fail to observe,

that the diversity of operations which the needles undergo bears the

impress of great mechanical refinement. In the arts, to divide labour,

is to abridge it; to multiply operations, is to simplify them; and to

attach an operative exclusively to one process, is to render him much

more economical and productive.

NEROLI, is the name given by perfumers to the essential oil of orange

flowers. It is procured by distillation with water, in the same way as

the other volatile oils. Since in distilling water from neroli, an aroma

is obtained different from that of the orange-flower, it has been

concluded that the distilled water of orange-flowers owes its scent to

some principle different from an essential oil.

NET (_Filet_, _reseau_, Fr.; _Netz_, Germ.); is a textile fabric of

knotted meshes, for catching fish, and other purposes. Each mesh should

be so secured as to be incapable of enlargement or diminution. The

French government offered in 1802 a prize of 10,000 francs to the person

who should invent a machine for making nets upon automatic principles,

and adjudged it to M. Buron, who presented his mechanical invention to

the _Conservatoire des Arts et Métiers_. It does not appear, however,

that this machine has accomplished the object in view; for no

establishment was ever mounted to carry it into execution. Nets are

usually made by the fishermen and their families during periods of

leisure. The formation of a mesh is too simple a matter to require

description in this Dictionary.

NEUTRALIZATION, is the state produced when acid and alkaline matters are

combined in such proportions that neither predominates, as evinced by

the colour of tincture of litmus and cabbage remaining unaffected by the

combination.

NICARAGUA WOOD, is the wood of the _Cæsalpinia echinata_, a tree which

grows in Nicaraca. It is used with solution of tin as a mordant to dye a

bright but fugitive red. It is an inferior sort of Brazil wood.

NICKEL, is a metal rather sparingly found, and in few localities; being

usually associated with cobalt. Native nickel occurs at Westerwald in

the Erzgebirge, in Bohemia, combined with arsenic, under the significant

name of _Kupfernickel_; with cobalt, iron, and copper, as

_Arsenic-nickel_, in the Harz; at Riechelsdorf in Hessia; as an oxide,

in _Nickelschwärtze_; as a sulphuret of nickel in _Haarkies_; as a

sulphuret and arseniate of nickel in _Nickelglanz_; and with sulphur and

antimony in _Nickelspiess glanzerz_ at Siegen. Nickel is always present

in meteoric stones. Kupfernickel occurs in numerous external shapes; as

reniform, globular, botroidal, arborescent, massive, and disseminated;

fracture, coarse or fine grained, with metallic lustre; colour, copper

red, occasionally brown and gray; in silver and cobalt veins, in gneiss,

sienite, mica-slate, kupfer-schiefer, accompanied by speisse cobalt,

native silver, quartz, &c. It is found in Westphalia near Olpe, in

Hessia at Riechelsdorf, and Biber, in Baden; in the Saxon Erzgebirge

near Schneeberg, and Freiberg; in Bohemia, at Joachimsthal; in

Thuringia, at Saalfeld; in Steyermark near Schladming; in Hungary,

France, and England.

Since the manufacture of German silver, or _Argentane_, became an object

of commercial importance, the extraction of nickel has been undertaken

upon a considerable scale. The cobalt ores are its most fruitful

sources, and they are now treated by the method of Wöhler, to effect the

separation of the two metals. The arsenic is expelled by roasting the

powdered _speise_ first by itself, next with the addition of charcoal

powder, till the garlic smell be no longer perceived. The residuum is to

be mixed with three parts of sulphur and one of potash, melted in a

crucible with a gentle heat, and the product being edulcorated with

water, leaves a powder of metallic lustre, which is a sulphuret of

nickel free from arsenic; while the arsenic associated with the sulphur,

and combined with the resulting sulphuret of potassium, remains

dissolved. Should any arsenic still be found in the sulphuret, as may

happen if the first roasting heat was too great, the above process must

be repeated. The sulphuret must be finally washed, dissolved in

concentrated sulphuric acid, with the addition of a little nitric, the

metal must be precipitated by a carbonated alkali, and the carbonate

reduced with charcoal.

In operating upon kupfernickel, or speise, in which nickel predominates,

after the arsenic, iron, and copper have been separated, ammonia is to

be digested upon the mixed oxides of cobalt and nickel, which will

dissolve them into a blue liquor. This being diluted with distilled

water deprived of its air by boiling, is to be decomposed by caustic

potash, till the blue colour disappears, when the whole is to be put

into a bottle tightly stoppered, and set aside to settle. The green

precipitate of oxide of nickel, which slowly forms, being freed by

decantation from the supernatant red solution of oxide of cobalt, is to

be edulcorated and reduced to the metallic state in a crucible

containing crown glass. Pure nickel in the form of a metallic powder is

readily obtained by exposing its oxalate to moderate ignition.

The reduction of the oxide of nickel with charcoal requires the heat of

a powerful air furnace or smith’s forge.

Nickel possesses a fine silver white colour and lustre; it is hard, but

malleable, both hot and cold; may be drawn into wire 1/50 of an inch,

and rolled into plates 1/500 of an inch thick. A small quantity of

arsenic destroys its ductility. When fused it has a specific gravity of

8·279, and when hammered, of 8·66 or 8·82; it is susceptible of

magnetism, in a somewhat inferior degree to iron, but superior to

cobalt. Mariner’s compasses may be made of it. Its melting point is

nearly as high as that of manganese. It is not oxidized by contact of

air, but may be burned in oxygen gas.

There is one oxide and two suroxides of nickel. The oxide is of an

ash-gray colour, and is obtained by precipitation with an alkali from

the solution of the muriate or nitrate. The niccolous suroxide of

Berzelius is black, and may be procured by exposing the nitrate to a

heat under redness. The niccolic suroxide has a dirty pale green colour;

but its identity is doubtful.

NICOTIANINE, is the name of an oil recently extracted from the leaves of

tobacco, which possesses the smell of tobacco smoke.

NICOTINE, is a peculiar principle, obtainable from the leaves and seeds

of tobacco (_nicotiana tabacum_), by infusing them in acidulous water,

evaporating the infusion to a certain point, adding lime to it,

distilling and treating the product which comes over with ether. It is

colourless, has an acrimonious taste, a pungent smell, remains liquid at

20° F., mixes in all proportions with water, but is in a great measure

separable from it by ether, which dissolves it abundantly. It combines

with acids, and forms salts acrid and pungent like itself; the

phosphate, oxalate, and tartrate being crystallizable. Nicotine causes

the pupils to contract. A single drop of it is sufficient to kill a dog.

NITRATE OF AMMONIA, is prepared by neutralizing nitric acid with

carbonate of ammonia, and crystallizing the solution.

NITRATE OF LEAD (_Nitrate de plomb_, Fr.; _Salpetersaures bleioxyd_,

Germ.); is made by saturating somewhat dilute nitric acid with oxide of

lead (litharge), evaporating the neutral solution till a pellicle

appears, and then exposing it in a hot chamber till it be converted into

crystals, which are sometimes transparent, but generally opaque white

octahedrons. Their spec. grav. is 4·068; they have a cooling, sweetish,

pungent taste. They dissolve in 7 parts of cold, and in much less

boiling water; they fuse at a moderate elevation of temperature, emit

oxygen gas, and pass into oxide of lead. Their constituents are 67·3

oxide, and 32·7 acid. Nitrate of lead is much employed in the chrome

yellow style of CALICO-PRINTING; which see.

There are three other compounds of nitric acid and lead oxide; viz. the

bi-basic, the tri-basic, and the se-basic; which contain respectively 2,

3, and 6 atoms of base to 1 of acid.

NITRATE OF POTASH, _Nitre_, _Saltpetre_. (_Nitrate de potasse_, Fr.;

_Salpetersaures kali_, Germ.) This salt occurs native as an

efflorescence upon limestones, sandstones, marls, chalk, and calctuff;

it forms a saline crust in caverns, as also upon the surface of the

ground in certain places, especially where animal matters have been

decomposed. Such caverns exist in Germany near Homburg (Burkardush); in

Apulia upon the Adriatic sea (Pulo di Mofetta); in France; in the East

Indies; in Ceylon, where 22 nitriferous caverns are mentioned; in North

America, at Crooked river, Tennessee, Kentucky, and upon the Missouri;

in Brazil, Teneriffe, and Africa. Nitre occurs as an efflorescence upon

the ground in Arragon, Hungary, Podolia, Sicily, Egypt, Persia, Bengal,

China, Arabia, North America, and South America. Several plants contain

saltpetre; particularly borage, dill, tobacco, sunflowers, stalks of

maize, beet-root, bugloss, parietaria, &c. It has not hitherto been

found in animal substances.

The question has been frequently put; how is nitre annually reproduced

upon the surface of limestones, and the ground, after it has been

removed by washing? It has been said, in reply, that as secondary

limestones contain remains of animal matters, the oxygen of the

atmosphere, absorbed in virtue of the porous structure, will combine

with their azote to form nitric acid; whence nitrate of lime will

result. Where potash is present in the ground, a nitrate of that base

will be next formed. The generation of nitre is in all cases limited to

a very small distance from the surface of porous stones; no further,

indeed, than where atmospherical air and moisture can penetrate; and

none is ever produced upon the surface of compact stones, such as marble

and quartz, or of argillaceous minerals. Dr. John Davy and M. Longchamp

have advanced an opinion, that the presence of azotized matter is not

necessary for the generation of nitric acid or nitrous salts, but that

the oxygen and azote of the atmosphere, when condensed by capillarity,

will combine in such proportions as to form nitric acid, through the

agency of moisture and of neutralizing bases, such as lime, magnesia,

potash, or soda. They conceive that as spongy platina serves to combine

oxygen and hydrogen into water, or the vapour of alcohol and oxygen into

acetic acid, and as the peroxide as well as the hydrate of iron, and

argillaceous minerals, serve to generate ammonia from the oxygen of the

air and the hydrogen of water; in like manner, porous limestones,

through the agency of water, operate upon the constituents of the

atmosphere to produce nitric acid, without the presence of animal

matter. This opinion may certainly be maintained: for in India, Spain,

and several other countries, at a distance from all habitations, immense

quantities of saltpetre are reproduced in soils which have been washed

the year before. But, on the other hand, it is known that the production

of this salt may be greatly facilitated and increased by the admixture

of animal offals with calcareous earths.

The spontaneous generation of nitre in Spain, Egypt, and especially in

India, is sufficient to supply the wants of the whole world. There this

salt is observed to form upon the surface of the ground in silky tufts,

or even in slender prismatic crystals, particularly during the

continuance of the hot weather that succeeds copious rains. These saline

efflorescences, after being collected by rude besoms of broom, are

lixiviated, allowed to settle, evaporated, and crystallized. In France,

Germany, Sweden, Hungary, &c., vast quantities of nitrous salts are

obtained by artificial arrangements called _nitriaries_, or nitre-beds.

Very little nitrate of potash, indeed, is obtained in the first place;

but the nitrates of lime and magnesia, which being deliquescent, remain

in the nitrous earths in a semi-liquid state. The operation of

converting these salts into good nitre is often sufficiently complex, in

consequence of the presence of several muriates, which are difficult to

eliminate.

The following instructions have been given by the consulting committee

of _poudres et salpêtres_ in France, for the construction of their

_nitrières artificielles_. The permeability of the materials to the

atmospherical air, being found to be as indispensable as is the presence

of a base to fix the nitric acid at the instant of its formation, the

first measure is to select a light friable earth, containing as much

carbonate of lime or old mortar-rubbish as possible; and to

interstratify it with beds of dung, five or six inches thick, till a

considerable heap be raised in the shape of a truncated pyramid, which

should be placed under an open shed, and kept moist by watering it from

time to time. When the whole appears to be decomposed into a kind of

mould, it is to be spread under sheds in layers of from two to three

feet thick; which are to be watered occasionally with urine and the

drainings of dunghills, taking care not to soak them too much, lest they

should be rendered impermeable to the air, though they should be always

damp enough to favour the absorption and mutual action of the

atmospherical gases. Moist garden mould affords an example of the

physical condition most favourable to nitre-beds. The compost should be

turned over, and well mixed with the spade once at least in every

fortnight, and the sides of the shed should be partially closed, for

although air be essential, wind is injurious, by carrying off the acid

vapours, instead of allowing them to rest incumbent upon, and combine

with, the bases. The chemical reaction is slow and successive, and can

be made effective only by keeping the agents and materials in a state of

quiescence. The whole process lasts two years; but since organic matters

would yield in the lixiviation several soluble substances detrimental to

the extraction of saltpetre, they must not be added during the

operations of the latter six months; nor must any thing except clear

water be used for watering during this period; at the end of which the

whole organic ingredients of the beds will be totally decomposed. Where

dung is not sufficiently abundant for the above stratifications, a

nitre-bed should be formed in a stable with friable earth, covered with

a layer of litter; after four months the litter is to be lifted off, the

earth is to be turned over, then another layer of fresh earth, 8 or 9

inches thick, is to be placed over it, and a layer of the old and fresh

litter over all. At the end of other four months, this operation is to

be repeated; and in the course of a year the whole is ready to be

transferred into the regular nitre-beds under a shed, as above

described. Such are the laborious and disagreeable processes practised

by the peasants of Sweden, each of whom is bound by law to have a

nitre-bed, and to furnish a certain quantity of nitre to the state every

year. His _nitriary_ commonly consists of a small hut built of boards,

with a bottom of rammed clay, covered by a wooden floor, upon which is

spread a mixture of ordinary earth with calcareous sand or marl, and

lixiviated wood-ashes. This mixture is watered with stable urine, and

its surface is turned over once a week in summer, and once a fortnight

in winter. In some countries, walls 2 or 3 feet thick, and 6 or 7 high,

are raised with the nitrifying compost, interspersed with weeds and

branches of trees, in order at once to bind them together, and to favour

the circulation of air. These walls are thatched with straw; they are

placed with one of their faces in the direction of the rains; and must

be moistened with water not rich in animal matter. One side of the walls

is upright and smooth; while the other is sloped or terraced, to favour

the admission of humidity into their interior. The nitre eventually

forms a copious efflorescence upon the smooth side, whence it may be

easily scraped off.

M. Longchamp, convinced that organic matters are a useless expense, and

not in the least essential to nitrification, proposes to establish

nitre-beds where fuel and labour are cheapest, as amidst forests,

choosing as dry and low a piece of ground as possible, laying them out

upon a square space of about 1000 feet in each side, in the middle of

which the graduation-house may be built, and alongside of it sheds for

the evaporation furnaces and pans. Upon each of the four sides the

_nitrifying_ sheds are to be erected, 130 feet long by 30 feet wide,

where the lixiviation would be carried on, and whence the water would be

conducted in gutters to the graduation-house. The sheds are to be closed

at the sides by walls of _pisé_, and covered with thatch. No substance

is so favourable to nitrification as the natural stony concretion known

under the name of lime-tuf. In Touraine, where it is used as a building

stone, the saltpetre makers re-establish the foundations of old houses

at their own expense, provided they are allowed to carry off the old

tuf, which owes its nitrifying properties not only to its chemical

nature, but to its texture, which being of a homogeneous porosity,

permits elastic fluids and vapours to pass through it freely in all

directions. With the rough blocks of such tuf, walls about 20 inches

thick, and moderately high, are to be raised, upon the principles above

prescribed; in the absence of tuf, porous walls may be raised with a

mixture of arable soil, sand, and mortar-rubbish, chalk or rich marl.

The walls ought to be kept moist.

In France, the greater part of the indigenous saltpetre is obtained by

lixiviating the mortar-rubbish of old buildings, especially of those

upon the ground-floor, and in sunk cellars; which are by law reserved

for this purpose. The first object of the manufacturer is then to

ascertain the richness of his materials in nitrous salts, to see if they

be worth the trouble of working; and this point he commonly determines

merely by their saline, bitter, and pungent taste, though he might

readily have recourse to the far surer criteria of lixiviation and

evaporation. He next pounds them coarsely, and puts them into large

casks open at top, and covered with straw at bottom; which are placed in

three successive levels. Water is poured into the casks till they are

full, and after 12 hours’ digestion it is run off, loaded with the

salts, by a spigot near the bottom. A fresh quantity of water is then

added, and drawn off after an interval of four hours; even a third and

fourth lixiviation are had recourse to; but these weak liquors are

reserved for lixiviating fresh rubbish. The contents of the casks upon

the second and third lower levels are lixiviated with the liquors of the

upper cask, till the lyes indicate from 12 to 14 degrees of Baumé’s

hydrometer. They are now fit for evaporating to a greater density, and

of then receiving the dose of wood-ashes requisite to convert the

materials of lime and magnesia into nitrate of potash, with the

precipitation of the carbonates of magnesia and lime. The solution of

nitre is evaporated in a copper pan, and as it boils, the scum which

rises to the surface must be diligently skimmed off into a cistern

alongside. Muriate of soda being hardly more soluble in boiling than in

cold water, separates during the concentration of the nitre, and is

progressively removed with cullender-shaped ladles. The fire is

withdrawn whenever the liquor has acquired the density of 80° B.; it is

allowed to settle for a little while, and is then drawn off, by a lead

syphon adjusted some way above the bottom, into iron vessels, to cool

and crystallize. The crystals thus obtained are set to drain, then

re-dissolved and re-crystallized. The further purification of nitre, is

fully described under the article GUNPOWDER.

The annual production of saltpetre in France, by the above-described

processes, during the wars of the Revolution, amounted to 2000 tons (2

millions of kilogrammes) of an article fit for the manufacture of

gunpowder; of which seven-twentieths were furnished by the saltpetre

works of Paris alone. Considerably upwards of six times that quantity of

common and cubic nitre were imported into the United Kingdom, for home

consumption, during the year ending January 5, 1838.

Nitrate of potash crystallizes in six-sided prisms, with four narrow and

two broad faces: the last being terminated by a dihedral summit, or

two-sided acumination; they are striated lengthwise, and have fissures

in their long axis, which are apt to contain mother water. The spec.

gravity of nitre, varies from 1·93 to 2·00. It possesses a cooling,

bitterish-pungent taste, is void of smell, permanent in the air when

pure, fuses at a heat of about 662, into an oily-looking liquid, and

concretes upon cooling into a solid mass, with a coarsely radiating

fracture. This has got the unmeaning names of sal-prunelle and mineral

crystal. At a red heat, nitre gives out at first a great deal of pretty

pure oxygen gas; but afterwards nitrous acid fumes, while potash remains

in the retort. It is soluble in 7 parts of water at 32°; in about 3-1/2

at 60° F., in less than half a part at 194°, and in four-tenths at 212°.

It is very slightly soluble in spirit of wine, and not at all in

absolute alcohol. It causes a powerful deflagration when thrown upon

burning coals; and when a mixture of it with sulphur is thrown into a

red-hot crucible, a very vivid light is emitted. Its constituents are,

46·55 potash, and 53·45 nitric acid.

Nitre is applied to many purposes:--1, to the manufacture of gunpowder;

2, to that of sulphuric acid; 3, to that of nitric acid, though nitrate

of soda or cubic nitre has lately superseded this use of it to a

considerable extent; 4, to that of flint-glass; 5, it is used in

medicine; 6, for many chemical and pharmaceutical preparations; 7, for

procuring by deflagration with charcoal or cream of tartar, pure

carbonate of potash, as also black and white fluxes; 8, for mixing with

salt in curing butcher meat; 9, in some countries for sprinkling in

solution upon grain, to preserve it from insects; 10, for making

fire-works. See FIRE-WORKS.

An Account of the quantities of Saltpetre and Cubic Nitre imported into,

exported from, and retained for consumption in the United Kingdom. Duty

6_d._ per cwt:--

Imported in

1835. 1836. 1837.

cwts. 264,338; 279,902; 349,993.

Exported in

1835. 1836. 1837.

cwts. 73,379; 38,414; 93,024.

Retained for Consumption in

1835. 1836. 1837.

cwts. 204,580; 242,131; 256,969.

Duty received in 1837, _£_6,424.

NITRATE OF SILVER (_Nitrate d’argent_, Fr.; _Silbersalpeter_, Germ.); is

prepared by saturating pure nitric acid of specific grav. 1·25 with pure

silver, evaporating the solution, and crystallizing the nitrate. When

the drained crystals are fused in a platina capsule, and cast into

slender cylinders in silver moulds, they constitute the lunar caustic of

the surgeon. This should be white, and unchangeable by light. It is

deliquescent in moist air. The crystals are colourless transparent 4 and

6 sided tables; they possess a bitter, acrid, and most disagreeable

metallic taste; they dissolve in their own weight of cold, and in much

less of hot water; are soluble in four parts of boiling alcohol, but not

in nitric acid; they deflagrate on redhot coals, like all the nitrates;

and detonate with phosphorus when the two are struck together upon an

anvil. They consist of 68·2 of oxide, and 31·8 of acid. Nitrate of

silver, when swallowed, is a very energetic poison: but it may be

readily counteracted, by the administration of a dose of sea-salt, which

converts the corrosive nitrate into the inert chloride of silver. Animal

matter, immersed in a weak solution of neutral nitrate of silver, will

keep unchanged for any length of time; and so will polished iron or

steel. Nitrate of silver is such a delicate reagent of hydrochloric or

muriatic acid, as to show by a sensible cloud, the presence of one 113

millionth part of it, or one 7 millionth part of sea-salt in distilled

water. It is much used under the name of indelible ink, for writing upon

linen with a pen; for which purpose one drachm of the fused salt should

be dissolved in three quarters of an ounce of water, adding to the

solution as much water of ammonia as will re-dissolve the precipitated

oxide, with sap-green to colour it, and gum-water to make the volume

amount to one ounce. Traces written with this liquid should be first

heated before a fire to expel the excess of ammonia, and then exposed to

the sun-beam to blacken. Another mode of using nitrate of silver as an

indelible ink, is to imbue the linen first with solution of carbonate of

soda, to dry the spot, and write upon it with a solution of nitrate of

silver, thickened with gum, and tinted with sap-green.

NITRATE OF SODA, _Cubical Nitre_ (_Nitrate de soude_, Fr.;

_Würfelsalpeter_, Germ.); occurs under the nitre upon the lands in

Spain, India, Chile, and remarkably in Peru, in the districts of Atacama

and Taracapa, where it forms a bed several feet thick. It appears in

several places upon the surface, and extends over a space of more than

40 leagues, approaching near to the frontiers of Chile. It is sometimes

efflorescent, sometimes crystallized, but oftener confusedly mixed with

clay and sand. This immensely valuable deposit is only three days’

journey from the port of Conception in Chile, and from Iquiqui, another

harbour situated in the southern part of Peru.

Nitrate of soda may be artificially prepared by neutralizing nitric acid

with soda, and crystallizing the solution. It crystallizes in rhomboids,

has a cooling, pungent, bitterish taste, less disagreeable than nitre;

it becomes moist in the air; dissolves in 3 parts of water at 60° F., in

less than 1 part of boiling water; deflagrates more slowly than nitre,

and with an orange yellow flame. It consists, in its dry state, of 36·6

soda and 63·4 nitric acid; but its crystals contain one prime

equivalent of water; hence they are composed of, acid 56·84, base 33·68,

water 9·47.

It is susceptible of the same applications as nitre, with the exception

of making gunpowder; for which it is not adapted, on account of its

deliquescent property.

NITRATE OF STRONTIA. (_Nitrate de strontiane_, Fr.; _Salpetersaurer

strontian_, Germ.) This salt is usually prepared from the sulphuret of

strontium, obtained by decomposing sulphate of strontia with charcoal,

by strong ignition of the mixed powders in a crucible. This sulphuret

being treated with water, and the solution being filtered, is to be

neutralized with nitric acid, as indicated by the test of turmeric

paper; care being taken to avoid breathing the noxious sulphuretted

hydrogen gas, which is copiously disengaged. The neutral nitrate being

properly evaporated and set aside, affords colourless, transparent,

slender octahedral crystals. It has a cooling, yet somewhat acrid taste;

is soluble in 5 parts of cold, and in one half part of boiling water, as

also in alcohol; is permanent in the air, deflagrates upon burning

coals, gives off oxygen when calcined, and leaves caustic strontia. The

salt consists of 48·9 strontia and 51·1 nitric acid. That salt is

anhydrous; but there is another variety of it, which contains nearly 40

per cent. of water of crystallization, which occurs in large

octahedrons. This is preferred for fire-works, because by efflorescence

it is easily obtained in a fine powder, which mixes more intimately with

the chlorate of potash and charcoal, for the composition of the

brilliant red fires, now so much admired in theatrical conflagrations.

NITRIC ACID, _Aquafortis_ (_Acide nitrique_, Fr.; _Salpetersaüre_,

Germ.); exists, in combination with the bases, potash, soda, lime,

magnesia, in both the mineral and vegetable kingdoms. This acid is never

found insulated. It was distilled from saltpetre so long ago as the 13th

century, by igniting that salt, mixed with copperas or clay, in a

retort. Nitric acid is generated when a mixture of oxygen and nitrogen

gases, confined over water or an alkaline solution, has a series of

electrical explosions passed through it. In this way the salubrious

atmosphere may be converted into corrosive aquafortis. When a little

hydrogen is introduced into the mixed gases, standing over water, the

chemical agency of the electricity becomes more intense, and the acid is

more rapidly formed from its elements, with the production of some

nitrate of ammonia.

Nitric acid is usually made on the small scale by distilling, with the

heat of a sand-bath, a mixture of 3 parts of pure nitre, and 2 parts of

strong sulphuric acid, in a large glass retort, connected by a long

glass tube with a globular receiver surrounded by cold water. By a well

regulated distillation, a pure acid, of specific gravity 1·500, may be

thus obtained, amounting in weight to about two-thirds of the nitre

employed. To obtain easily the whole nitric acid, equal weights of nitre

and concentrated sulphuric acid may be taken; in which case but a

moderate heat need be applied to the retort. The residuum will be

bisulphate of potash. When only the single equivalent proportion of

sulphuric acid is used, namely 48 parts for 100 of nitre, a much higher

heat is required to complete the distillation, whereby more or less of

the nitric acid is decomposed, while a compact neutral sulphate of

potash is left in the retort, very difficult to remove by solution in

water, and therefore apt to destroy the vessel.

Aquafortis is manufactured upon the great scale in iron pots or

cylinders of the same construction as I have described under muriatic

acid. The more concentrated the sulphuric acid is, the less corrosively

will it act upon the metal; and it is commonly used in the proportion of

one part by weight to two of nitre. The salt being introduced into the

cool retort, and the lid being luted tight, the acid is to be slowly

poured in through the aperture _f_, _fig._ 748.; while the aperture _g_

is connected by a long glass tube with a range of balloons inserted into

each other, and laid upon a sloping bed of sand. The bottle _i_, with 3

tubulures partly filled with water, which is required for condensing

muriatic acid gas, must, for the present purpose, be replaced by a

series of empty receivers, either of glass or salt-glazed stoneware. The

cylinders should be only half filled, and be worked off by a gradually

raised heat.

Commercial aquafortis is very generally contaminated with sulphuric and

muriatic acids, as also with alkaline sulphates and muriates. The

quantity of these salts may be readily ascertained by evaporating in a

glass capsule a given weight of the aquafortis; while that of the

muriatic acid may be determined by nitrate of silver; and of sulphuric

acid, by nitrate of baryta. Aquafortis may be purified in a great

measure, by re-distillation at a gentle heat; rejecting the first liquid

which comes over, as it contains the chlorine impregnation; receiving

the middle portion as genuine nitric acid; and leaving a residuum in the

retort, as being contaminated with sulphuric acid.

Since nitrate of soda has been so abundantly imported into Europe from

Peru, it has been employed by many manufacturers in preference to nitre

for the extraction of nitric acid, because it is cheaper, and because

the residuum of the distillation, being sulphate of soda, is more

readily removed by solution from glass retorts, when a range of these

set in a gallery furnace is the apparatus employed. Nitric acid of

specific gravity 1·47 may be obtained colourless; but by further

concentration a portion of it is decomposed, whereby some nitrous acid

is produced, which gives it a straw-yellow tinge. At this strength it

exhales white or orange fumes, which have a peculiar, though not very

disagreeable smell; and even when largely diluted with water, it tastes

extremely sour. The greatest density at which it can be obtained is 1·51

or perhaps 1·52, at 60° F., in which state, or even when much weaker, it

powerfully corrodes all animal, vegetable, and most metallic bodies.

When slightly diluted it is applied, with many precautions, to silk and

woollen stuffs, to stain them of a bright yellow hue. See

CALICO-PRINTING; page 240.

In the dry state, as it exists in nitre, this acid consists of 26·15

parts by weight of azote, and 73·85 of oxygen; or of 2 volumes of the

first gas, and 5 volumes of the second.

When of specific gravity 1·5, it boils at about 210° Fahr.; of 1·45, it

boils at about 240°; of 1·42, it boils at 253°; and of 1·40, at 246° F.

If an acid stronger than 1·420 be distilled in a retort, it gradually

becomes weaker; and if weaker than 1·42, it gradually becomes stronger,

till it assumes that standard density. Acid of specific gravity 1·485

has no more action upon tin than water has, though when either stronger

or weaker it oxidizes it rapidly, and evolves fumes of nitrous gas with

explosive violence. In my two papers upon nitric acid published in the

fourth and sixth volumes of the Journal of Science (1818 and 1819), I

investigated the chemical relations of these phenomena. Acid of 1·420

consists of 1 atom of dry acid, and 4 of water; acid of 1·485, of 1 atom

of dry acid, and 2 of water; the latter compound possesses a stable

equilibrium as to chemical agency; the former as to calorific. Acid of

specific gravity 1·334, consisting of 7 atoms of water, and 1 of dry

acid, resists the decomposing agency of light. Nitric acid acts with

great energy upon most combustible substances, simple or compound,

giving up oxygen to them, and resolving itself into nitrous gas, or even

azote. Such is the result of its action upon hydrogen, phosphorus,

sulphur, charcoal, sugar, gum, starch, silver, mercury, copper, iron,

tin, and most other metals.

A Table of Nitric Acid, by Dr. Ure.

+--------+-------+--------+

|Specific| Liq. |Dry acid|

|gravity.| Acid |in 100. |

| |in 100.| |

+--------+-------+--------+

| 1·5000 | 100 | 79·700 |

| 1·4980 | 99 | 78·903 |

| 1·4960 | 98 | 78·106 |

| 1·4940 | 97 | 77·309 |

| 1·4910 | 96 | 76·512 |

| 1·4880 | 95 | 75·715 |

| 1·4850 | 94 | 74·918 |

| 1·4820 | 93 | 74·121 |

| 1·4790 | 92 | 73·324 |

| 1·4760 | 91 | 72·527 |

| 1·4730 | 90 | 71·730 |

| 1·4700 | 89 | 70·933 |

| 1·4670 | 88 | 70·136 |

| 1·4640 | 87 | 69·339 |

| 1·4600 | 86 | 68·542 |

| 1·4570 | 85 | 67·745 |

| 1·4530 | 84 | 66·948 |

| 1·4500 | 83 | 66·155 |

| 1·4460 | 82 | 65·354 |

| 1·4424 | 81 | 64·557 |

| 1·4385 | 80 | 63·760 |

| 1·4346 | 79 | 62·963 |

| 1·4306 | 78 | 62·166 |

| 1·4269 | 77 | 61·369 |

| 1·4228 | 76 | 60·572 |

| 1·4189 | 75 | 59·775 |

| 1·4147 | 74 | 58·978 |

| 1·4107 | 73 | 58·181 |

| 1·4065 | 72 | 57·384 |

| 1·4023 | 71 | 56·587 |

| 1·3978 | 70 | 55·790 |

| 1·3945 | 69 | 54·993 |

| 1·3882 | 68 | 54·196 |

| 1·3833 | 67 | 53·399 |

| 1·3783 | 66 | 52·602 |

| 1·3732 | 65 | 51·805 |

| 1·3681 | 64 | 51·068 |

| 1·3630 | 63 | 50·211 |

| 1·3579 | 62 | 49·414 |

| 1·3529 | 61 | 48·617 |

| 1·3477 | 60 | 47·820 |

| 1·3427 | 59 | 47·023 |

| 1·3376 | 58 | 46·226 |

| 1·3323 | 57 | 45·429 |

| 1·3270 | 56 | 44·632 |

| 1·3216 | 55 | 43·835 |

| 1·3163 | 54 | 43·038 |

| 1·3110 | 53 | 42·241 |

| 1·3056 | 52 | 41·444 |

| 1·3001 | 51 | 40·647 |

| 1·2947 | 50 | 39·850 |

| 1·2887 | 49 | 39·053 |

| 1·2826 | 48 | 38·256 |

| 1·2765 | 47 | 37·459 |

| 1·2705 | 46 | 36·662 |

| 1·2644 | 45 | 35·865 |

| 1·2583 | 44 | 35·068 |

| 1·2523 | 43 | 34·271 |

| 1·2462 | 42 | 33·474 |

| 1·2402 | 41 | 32·677 |

| 1·2341 | 40 | 31·880 |

| 1·2277 | 39 | 31·083 |

| 1·2212 | 38 | 30·286 |

| 1·2148 | 37 | 29·489 |

| 1·2084 | 36 | 28·692 |

| 1·2019 | 35 | 27·895 |

| 1·1958 | 34 | 27·098 |

| 1·1895 | 33 | 26·301 |

| 1·1833 | 32 | 25·504 |

| 1·1770 | 31 | 24·707 |

| 1·1709 | 30 | 23·900 |

| 1·1648 | 29 | 23·113 |

| 1·1587 | 28 | 22·316 |

| 1·1526 | 27 | 21·519 |

| 1·1465 | 26 | 20·722 |

| 1·1403 | 25 | 19·925 |

| 1·1345 | 24 | 19·128 |

| 1·1286 | 23 | 18·331 |

| 1·1227 | 22 | 17·534 |

| 1·1168 | 21 | 16·737 |

| 1·1109 | 20 | 15·940 |

| 1·1051 | 19 | 15·143 |

| 1·0993 | 18 | 14·346 |

| 1·0935 | 17 | 13·549 |

| 1·0878 | 16 | 12·752 |

| 1·0821 | 15 | 11·955 |

| 1·0764 | 14 | 11·158 |

| 1·0708 | 13 | 10·361 |

| 1·0651 | 12 | 9·564 |

| 1·0595 | 11 | 8·767 |

| 1·0540 | 10 | 7·970 |

| 1·0485 | 9 | 7·173 |

| 1·0430 | 8 | 6·376 |

| 1·0375 | 7 | 5·579 |

| 1·0320 | 6 | 4·782 |

| 1·0267 | 5 | 3·985 |

| 1·0212 | 4 | 3·188 |

| 1·0159 | 3 | 2·391 |

| 1·0106 | 2 | 1·594 |

| 1·0053 | 1 | 0·797 |

+--------+-------+--------+

NITROGEN, DEUTOXIDE OF; _Nitrous gas_, _Nitric oxide_ (_Deutoxide

d’azote_, Fr.; _Stickstoffoxyd_, Germ.); is a gaseous body which may be

obtained by pouring upon copper or mercury, in a retort, nitric acid of

moderate strength. The nitrous gas comes over in abundance without the

aid of heat, and may be received over water freed from air, or over

mercury, in the pneumatic trough. It is elastic and colourless; what

taste and smell it possesses are unknown, because the moment it is

exposed to the mouth or nostrils, it absorbs atmospherical oxygen, and

becomes nitrous or nitric acid. Its specific gravity is 1·0393, or 1·04;

whence 100 cubic inches weigh 36·66 gr. Water condenses not more than

1/20 of its volume of this gas. It extinguishes animal life, and the

flame of many combustibles; but of phosphorus well kindled, it brightens

the flame in a most remarkable degree. It consists of 47 parts of

nitrogen gas, and 53 of oxygen gas, by weight; and of equal parts in

bulk, without any condensation; so that the specific gravity of

deutoxide of nitrogen is the arithmetical mean of the two constituents.

The constitution of this gas, and the play of affinities which it

exercises in the formation of sulphuric acid, are deeply interesting to

the chemical manufacturer.

_The Hyponitrous acid_ (_Salpetrigesaüre_, Germ.), like the preceding

compound, deserves notice here, on account of the part it plays in the

conversion of sulphur into sulphuric acid, by the agency of nitre. It is

formed by mingling four volumes of deutoxide of nitrogen with one volume

of oxygen; and appears as a dark orange vapour which is condensable into

a liquid at a temperature of 4° -zero, Fahr. When distilled, this liquid

leaves a dark yellow fluid. The pure hyponitrous acid consists of 37·12

nitrogen, and 62·88 oxygen; or of two volumes of the first, and three of

the second. Water converts it into nitric acid and deutoxide of

nitrogen; the latter of which escapes with effervescence. This acid

oxidizes most combustible bodies with peculiar energy and though its

vapour does not operate upon dry sulphurous acid, yet, through the

agency of steam it converts it into sulphuric acid, itself being

simultaneously transformed into deutoxide of nitrogen; ready to become

hyponitrous acid again, and to perform a circulating series of important

metamorphoses. See SULPHURIC ACID.

NITROGEN GAS, or AZOTE (Eng. and Fr.; _Stickstoffgas_, Germ.);

constitutes about 79 hundredths of the bulk of the atmospheric air; it

is copiously disengaged from several mineral springs, as from the

natural basins of hot water which supply the baths of Leuk, near the

Gemmi in Switzerland, and from other springs, in the Pyrenees, in

Ceylon, South and North America, &c. It exists also in flesh and most

animal substances, as well as in some vegetable products, being one of

their essential constituents. When phosphorus is burnt within a jar

filled with air, standing over water in the pneumatic trough, it

consumes or absorbs the oxygen, and leaves nitrogen, which may be

rendered pure by agitation with water. By exposing nitrite of ammonia to

heat in a retort, nitrogen comes over alone in great abundance; for the

hydrogen of the ammonia is sufficient to saturate the oxygen of the

acid, and to convert it into water; while the nitrogen of both

constituents is set at liberty. By transmitting chlorine through water

of ammonia, or digesting lean flesh in warm nitric acid, nitrogen may

also be obtained. This permanently elastic gas is destitute of colour,

taste, and smell; it has a specific gravity of 0·976, air being 1·000.

Hence 100 cubic inches of it weigh 29·7 gr. It extinguishes all burning

bodies, and when respired without oxygen is fatal to animal life.

NITROGEN, PROTOXIDE OF; _Nitrous oxide_ (_Protoxide d’azote_, Fr.;

_Stickstoffoxydul_, Germ.); is a gas which displays remarkable powers

when breathed, causing in many persons unrestrainable feelings of

exhilaration, whence it has been called the laughing or intoxicating

gas. It is prepared by exposing crystallized nitrate of ammonia to a

heat of about 350° Fahr., in a glass retort. It is much denser than the

air of the atmosphere, having a spec. grav. of 1·527; whence 100 cubic

inches weigh 46·6 grains. It consists of 63·64 parts of nitrogen, and

36·36 of oxygen, by weight; or of two volumes of nitrogen and one volume

of oxygen, condensed by reciprocal attraction into two volumes. It is

colourless, and possesses all the mechanical properties of the

atmosphere. Water previously freed from air absorbs its own volume of

this gas; and thus affords a ready criterion for estimating its freedom

from incondensable gases, as oxygen, nitrogen, and its deutoxide.

Several combustibles burn in this gas with an enlarged blue and very

vivid flame; and it relumes a taper, which has been blown out, provided

its tip be redhot. By powerful pressure it may be liquefied. See GAS.

NITRO-MURIATIC ACID, _Aqua regia_ (_Acide nitro-muriatique_, Fr.;

_Salpeter-salzsaüre, Königswasser_, Germ.); is the compound menstruum

invented by the alchemists for dissolving gold. If strong nitric acid,

orange-coloured by saturation with nitrous gas (deutoxide of azote), be

mixed with the strongest liquid muriatic acid, no other effect is

produced than might be expected from the action of nitrous acid of the

same strength upon an equal quantity of water; nor has the mixed acid so

formed, any power of acting upon gold or platina. But if colourless

aquafortis and ordinary muriatic acid be mixed together, the mixture

immediately becomes yellow, and acquires the power of dissolving these

two noble metals. When gently heated, pure chlorine gas rises from it,

and its colour becomes deeper; when further heated, chlorine still

rises, but now mixed with nitrous acid gas. If the process has been very

long continued, till the colour becomes very dark, no more chlorine can

be procured, and the liquor has lost the power of dissolving gold. It

then consists of nitrous and muriatic acids. It appears, therefore, that

aqua regia owes its peculiar properties to the mutual decomposition of

the nitric and muriatic acids; and that water, chlorine, and nitrous

acid gas are the results of that reaction. Aqua regia does not, strictly

speaking, oxidize gold and platinum; it causes merely their combination

with chlorine. It may be composed of very different proportions of the

two acids; the nitric being commonly of specific gravity 1·34; the

muriatic, of specific gravity 1·18 or 1·19. Sometimes 3 parts, and at

others 6 parts of the muriatic acid are mixed with 1 of nitric; and

occasionally muriate of ammonia, instead of muriatic acid, is added to

nitric acid for particular purposes, as for making a solution of tin for

the dyers. An aqua regia may also be prepared by dissolving nitre in

muriatic acid.

NITROUS ACID (_Acide nitreux_, Fr.; _Salpetrige salpetersaüre_, Germ.),

may be procured by distilling, in a coated glass retort, perfectly dry

nitrate of lead, into a glass receiver surrounded with a freezing

mixture. The acid passes over in vapour, and condenses into a liquid;

oxygen gas escapes through the safety tube; while oxide of lead remains

in the bottom of the retort. Nitrous acid may also be obtained by

distilling strong fuming nitric acid, at the lowest possible

temperature, and rectifying what comes over. At 4° -zero, Fahr., this

acid is colourless; at 32° it is wax yellow; at 60° it has an orange

hue. It possesses a strong smell, has a very pungent, acrid, sour taste,

and a specific gravity of 1·42. It powerfully decomposes organic bodies,

staining them yellow. It boils at 82° Fahr. with the disengagement of

red or orange fumes. Its constituents are, 41·34 of hyponitrous acid,

and 58·66 of anhydrous nitric acid; or ultimately, 30·68 nitrogen = 1

volume, and 69·32 oxygen = 2 volumes. In its other habitudes, it is

quite analogous to hyponitrous acid.

A mixture of this double or compound acid with nitric acid, constitutes

the orange-brown fuming nitrous acid of the British apothecaries.

The hyponitrous and nitrous are two acids remarkable for containing no

water in their composition; being therefore _dry liquids_.

NOPAL, is the Mexican name of the plant _cactus opuntia_, upon which the

cochineal insect breeds.

NUTMEG (_Muscade_, Fr.; _Muskatennuss_, Germ.); is the fruit of the

_myristica moschata_, a beautiful tree of the family of the _laurineæ_

of Jussieu, which grows in the Molucca islands. All the parts of this

tree are very aromatic; but only those portions of the fruit called mace

and nutmeg are sent into the market. The entire fruit is a species of

_drupa_, of an ovoid form, of the size of a peach, and furrowed

longitudinally. The nutmeg is the innermost kernel, or seed, contained

in a thin shell, which is surrounded by the mace; and this again is

enclosed in a tough fleshy skin, which opening at the tip, separates

into two valves. The nutmeg tree yields three crops annually; one in

April, which is the best; one in August; and one in December.

Good nutmegs should be dense, and feel heavy in the hand. When they have

been perforated by worms, they feel light, and though the holes have

been fraudulently stopped, the unsound ones may be easily detected by

this criterion.

_Nutmegs_ afford two oily products. 1. Butter of nutmeg, vulgarly called

oil of mace, is obtained in the Moluccas, by expression, from the fresh

nutmegs, to the amount of 50 per cent. of their weight. It is a reddish

yellow butter-like substance, interspersed with light and dark streaks,

and possesses the agreeable smell and taste of the nutmeg, from the

presence of a volatile oil. It consists of two fats; one reddish and

soft, soluble in cold alcohol; another white and solid, soluble in hot

alcohol. 2. The volatile oil is solid, or a _stereoptène_, and has been

styled _Myristicine_.

NUT OIL. See OILS, UNCTUOUS.

NUX VOMICA, a poisonous nut, remarkable for containing the vegeto-alkali

STRYCHNIA.