“Preparation for 24 pounds of scoured wool:
“Take 4-1/4 pounds of cream of tartar, 4-1/4 pounds of pure alum; boil
the wool gently for 2 hours, transfer it into a cool place, and wash it
next day in clear water.
“_Dyeing._--12 pounds of Avignon madder, infused half an hour at 30° R.
(100° F.) Put into the bath 1 pound of muriate of tin, let the colour
rose for three quarters of an hour at the same heat, and drain or
squeeze the madder through canvas. The whole of the red dye will remain
upon the filter, but the water which has passed through will be as deep
a yellow as a weld bath. The boiler with the dye must now be filled up
with clear river water, and heated to 100° F. Two ounces of the solution
of the tartar and alum must be poured into it, and the wool must be
turned over in it for an hour and a half, while the heat is gradually
raised to the boiling point. The wool is then removed and washed. It
must be rosed the following day.
“_Rosing._--Dissolve in hot water 1 pound of white Marseilles soap; let
the bath cool, and pass the wool through it till it has acquired the
desired shade; 15 or 20 minutes are sufficient. On coming out of this
bath it should be washed.
“_Solution of deuto-muriate of tin_:--
“2 ounces of pure muriatic acid; 4 drachms of pure nitric acid; 1 ounce
of distilled water. Dissolve in it, by small portions at a time, 2
drachms of grain tin, in a large bottle of white glass, shutting it
after putting in the tin. This solution may be preserved for years,
without losing its virtue.”
I have inserted this process, as recently recommended by the French
minister of commerce, and published by M. Pouillet in vol. i. of his
Portefeuille Industriel, to show what _official_ importance is sometimes
given by our neighbours to the most frivolous things.
Madders imported for home consumption. Gross amount of Duty paid in
1836. 1837. 1836. 1837.
Cwts. 106,172 | cwts. 79,228 | _£_10,810 | _£_8,081
MADREPORES, are calcareous incrustations produced by _polypi_ contained
in cells of greater or less depth, placed at the surface of calcareous
ramifications, which are fixed at their base, and perforated with a
great many pores. The mode of the increase, reproduction and death of
these animals is still unknown to naturalists. Living madrepores are
now-a-days to be observed only in the South American, the Indian, and
the Red seas; but although their polypi are not found in our climate at
present, there can be no doubt of their having existed in these northern
latitudes in former times, since fossil madrepores occur in both the
older and newer secondary strata of Europe.
MAGISTERY, is an old chemical term to designate white pulverulent
substances, spontaneously precipitated in making certain metallic
solutions; as magistery of bismuth.
MAGISTRAL, in the language of the Spanish smelters of Mexico and South
America, is the roasted and pulverized copper pyrites, which is added to
the ground ores of silver in their _patio_, or amalgamation magma, for
the purpose of decomposing the horn silver present. See SILVER, for an
account of this curious process of reduction.
MAGMA, is the generic name of any crude mixture of mineral or organic
matters, in a thin pasty state.
MAGNANIER, is the name given in the southern departments of France to
the proprietor of a nursery in which silk-worms are reared upon the
great scale, or to the manager of the establishment. The word is derived
from _magnans_, which signifies silkworms in the language of the country
people. See SILK.
MAGNESIA (Eng. and Fr.; _Bittererde_, _Talkerde_, Germ.), is one of the
primitive earths, first proved by Sir H. Davy to be the oxide of a
metal, which he called _magnesium_. It is a fine, light, white powder,
without taste or smell, which requires 5150 parts of cold water, and no
less than 36,000 parts of boiling water, for its solution. Its specific
gravity is 2·3. It is fusible only by the heat of the hydroxygen
blowpipe. A natural hydrate is said to exist which contains 30 per cent.
of water. Magnesia changes the purple infusion of red cabbage to a
bright green. It attracts carbonic acid from the air, but much more
slowly than quicklime. It consists of 61·21 parts of metallic basis, and
38·79 of oxygen; and has, therefore, 20 for its prime equivalent upon
the hydrogen scale. Its only employment in the arts is for the
purification of fine oil, in the preparation of varnish.
Magnesia may be obtained by precipitation with potash or soda, from its
sulphate, commonly called Epsom salt; but it is usually procured by
calcining the artificial or natural carbonate. The former is, properly
speaking, a subcarbonate, consisting of 44·69 magnesia, 35·86 carbonic
acid, and 19·45 water. It is prepared by adding to the solution of the
sulphate, or the muriate (the _bittern_ of sea-salt evaporation works),
a solution of carbonate of soda, or of carbonate of ammonia distilled
from bones in iron cylinders. The sulphate of magnesia is generally made
by acting upon magnesian limestone with somewhat dilute sulphuric acid.
The sulphate of lime precipitates, while the sulphate of magnesia
remains in solution, and may be made to crystallize in quadrangular
prisms, by suitable evaporation and slow cooling. Where muriatic acid
may be had in profusion for the trouble of collecting it, as in the soda
works in which sea salt is decomposed by sulphuric acid, the magnesian
limestone should be first acted upon with as much of the former acid as
will dissolve out the lime, and then, the residuum being treated with
the latter acid, will afford a sulphate at the cheapest possible rate;
from which magnesia and all its other preparations may be readily made.
Or, if the equivalent quantity of calcined magnesian limestone be boiled
for some time in bittern, the lime of the former will displace the
magnesia from the muriatic acid of the latter. This is the most
economical process for manufacturing magnesia. The subcarbonate, or
_magnesia alba_ of the apothecary, has been proposed by Mr. E. Davy to
be added by the baker to damaged flour, to counteract its acescency.
MAGNESIAN LIMESTONE (_Dolomie_, Fr.; _Bittertalk_, _Talkspath_, Germ.),
is a mineral which crystallizes in the rhombohedral system. Spec. grav.
2·86; scratches calc-spar; does not fall spontaneously into powder, when
calcined, as common limestone does. It consists of 1 prime equivalent of
carbonate of lime = 50, associated with 1 of carbonate of magnesia = 42.
_Massive magnesian limestone_, is yellowish-brown, cream-yellow, and
yellowish-gray; brittle. It dissolves slowly and with feeble
effervescence in dilute muriatic acid; whence it is called _Calcaire
lent dolomie_ by the French mineralogists. Specific gravity 2·6 to 2·7.
Near Sunderland, it is found in flexible slabs. The principal range of
hills composing this geological formation in England, extends from
Sunderland on the northeast coast to Nottingham, and its beds are
described as being about 300 feet thick on the east of the coal field in
Derbyshire, which is near its southern extremity. On the western side of
the Cumberland mountains magnesian limestone overlies the coal measures
near Whitehaven. The stratification of this rock is very distinct, the
individual courses of stone not exceeding in general the thickness of a
common brick.
The lime resulting from the calcination of magnesian limestone appears
to have an injurious action on vegetation, unless applied in quantities
considerably less than common lime, when it is found to fertilize the
soil. After two years, its hurtful influence on the ground seems to
become exhausted, even when used in undue quantity. Great quantities of
it are annually brought from Sunderland to Scotland by the Fifeshire
farmers, and employed beneficially by them, as a manure, in preference
to other kinds of lime. It has been unfairly denounced by Mr. Tennent
and Sir H. Davy, as a sterilizer.
This rock is used in many places for building; indeed our most splendid
monument of Gothic architecture, York Minster, is constructed of
magnesian limestone.
MAGNESIA, NATIVE (_Brucite_; _Guhr magnésien_, Fr.; _Wassertalk_,
Germ.), is a white, lamellar, pearly-looking mineral, soft to the touch.
Spec. grav. 2·336; tender; scratched by calc-spar; affording water by
calcination; leaving a white substance which browns turmeric paper; and,
by calcination with nitrate of cobalt, becoming of a lilac hue. It
consists of 69·75 magnesia, and 30·25 water. It occurs in veins in the
serpentine at Hoboken, in New Jersey, as also at Swinaness, in the
island of Unst, Shetland.
MAGNESITE, _Giobertite_; native carbonate of magnesia, occurs in white,
hard, stony masses, in the presidency of Madras, and in a few other
localities. It dissolves very slowly in muriatic acid, and gives out
carbonic acid in the proportion of 22 parts by weight to 42 of the
mineral, according to my experiments, and is therefore an atomic
carbonate. It forms an excellent and beautiful mortar cement for
terraces; a purpose to which it has been beneficially applied in India
by Dr. Macleod.
MAGNET, NATIVE, is a mineral consisting of the protoxide and peroxide of
iron combined in equivalent proportions. See IRON.
MAHALEB. The fruit of this shrub affords a violet dye, as well as a
fermented liquor like _Kirschwasser_. It is a species of cherry
cultivated in our gardens.
MALACHITE, or _mountain green_, is native carbonate of copper of a
beautiful green colour, with variegated radiations and zones; spec.
grav. 3·5; it scratches calc-spar, but not fluor; by calcination it
affords water and turns black. Its solution in the acids, deposits
copper upon a plate of iron plunged into it. It consists of carbonic
acid 18·5; deutoxide of copper 72·2; water 9·3.