An inferior kind of plumbago is imported from Mexico and Ceylon; and a composition with which more common pencils are manufactured is made of a mixture of plumbago-powder, lamp black and clay.
I can, however, point out no mention of our plumbago in the works of the old Italian artists.
It is stated that the supply of plumbago from the Cumberland mine is almost exhausted; fortunately, a process has been devised by which the same firmness and equality may be communicated to the powder by compression.
How old then are the pits at Leizersdorf, which furnish plumbago for the crucibles of Ips or Passau?
According as the main line current was strong or weak, the pressure on the plumbago was more or less, and the current in the local circuit strong or weak.
As a matter of fact, powdered carbon and plumbago had been used in making small adjustable rheostats by M.
The teeth were composed of beech, and had been greased twice a week, with tallow and plumbago ore.
If cast iron, the crocus surface will appear as though polished with plumbago or blacklead, while in any case the crocus surface will be polished and quite dry.
The plumbago occurs both amorphous, and in long acicular crystals.
Ralph was largely interested in the road, which indeed he had both projected and promoted, to connect his plumbago mines and his phosphate lands with "the front," i.
As soon as he was left alone he took from a drawer some specimens of plumbagobrought from lands of his which the road he had been assisting to place under construction would open up.
Sir William Logan states[B] that "the deposits ofplumbago generally occur in the limestones or in their immediate vicinity, and granular varieties of the rock often contain large crystalline plates of plumbago.
Great quantities of carbon or charcoal in the form of the substance known as graphite or plumbago exist in the Laurentian.
He further states: "The plumbago is not confined to the limestones; large crystalline scales of it are occasionally disseminated in pyroxene rock, and sometimes in quartzite and in feldspathic rocks, or even in magnetic oxide of iron.
It was obvious, however, that carbon could only be so heated when in a space destitute of oxygen, and accordingly King placed hisplumbago rod in a barometric vacuum.
Long before this date, however, the notion of employing carbon as a substance to be heated by the current had entered the minds of inventors; even in 1845 King had employed a small rod of plumbago as the substance to be heated.
The plumbago must be reduced to a fine powder in an iron mortar, then put into a crucible, and calcined at a heat approaching to whiteness.
The same lustre may, however, be obtained by increasing the proportion of powdered plumbagorelatively to the clay.
If on cutting the indurated mass, particles of plumbago appear, the whole must be further levigated.
Conte, were formed of two parts of plumbago and three parts of clay; others of equal parts.
WADD, is the provincial name of plumbago in Cumberland; and also of an ore of manganese in Derbyshire, which consists of the peroxide of that metal, associated with nearly its own weight of oxide of iron.
All the operations are the same, except that some lamp-black is introduced along with the plumbago powder and the clay.
This substance is much used for effacing the traces of plumbago pencils, whence it derived the name of Indian-rubber.
Humblot found that the different degrees of hardness of crayons could not be obtained in a uniform manner by the mere mixture of plumbago and clay in determinate doses.
Pure clay, or clay containing the smallest proportion of calcareous or siliceous matter, is the substance which he employed to give aggregation and solidity, not only to plumbago dust, but to all sorts of coloured powders.
A portion of this plumbago is also converted into charcoal of a blackish brown colour, by the action of the chloride.
I think the shade is very much like that of the hardy Plumbago Lady Lapente, though I've never seen the two together.
With me it has only one rival among blue flowers and that is Plumbago Capense.
The minerals proved to exist up to the present time are gold, quicksilver, plumbago and iron.
Plumbago is disseminated throughout the whole of both soil and rocks in Ceylon, and may be seen covering the surface in the drains by the road side, after a recent shower.
It is invested with highly crystalline plumbago, and splits by the intervention of plates of plumbago into pyramidal and tetrahedral masses.
Plumbago experimented with in the same manner does not produce the effect.
Iodine is usually met with under the form of semi-crystalline lumps having a semi-metallic lustre, or in micaceous, friable scales, somewhat resembling plumbago or gunpowder.
In medicine plumbago has been used with apparent advantage in herpes and several chronic skin diseases--externally, as an ointment made with four times its weight of lard; and internally, made into pills.
Black teas are 'faced,' in a similar manner, with finely powdered plumbagoor black-lead.
The blocks of plumbago are exposed to a bright-red heat in a closely covered crucible, and are afterwards sawn into minute sticks, and mounted in cases of cedar or satin wood.
This name is applied to the small brushes made of camel's hair used by artists, as well as to the plumbago crayons familiarly known as black-lead pencils.
As the last, but employing shredded tow or plumbago for horse-dung.
The foliated graphite of Ceylon and other parts is the principal material employed for making plumbagocrucibles and other fire-resisting goods.
By heating a mixture of bitungstate of potash with sulphur, and washing the product with hot water, a black crystalline substance, having the above composition, may be obtained, resemblingplumbago in appearance.
The flower is not strikingly beautiful nor ravishingly scented, but it flowers nine months out of the year; smothered with street dust and scorched by the summer sun, you will find that faithful old plumbago plugging along undismayed.
The game fowls of your other neighbour come fluttering into your garden, and scratch and chuckle and fluff themselves under your plumbago bush; but you don't worry.
Sunday morning; to look out of your window at a lawn waving with the feathery plumes of Parramatta grass, and to see beyond it the churchyard geranium flourishing side by side with the plumbago and the Port Jackson fig?
Defn: Pertaining to natural order (Plumbagineæ) of gamopetalous herbs, of which plumbago is the type.
A substance which imparts luster to a surface, as plumbago and some of the glazes.
But since we shall not need to shut the window for some months to come, I give my vote to support Francis, and suffer the plumbago to do exactly as it likes.
Paraffins Peat Pecopteris Pennsylvanian anthracite Persian fire-worshippers Pitch Plumbago Polyzoa Prejudice against aniline dyes Prohibitions of the use of coal Proportions of explosive mixtures Psaronius "Purifiers" Pyrites in coal Q.
Other transformations take place after the stage of coal is reached, which, by the continued disentanglement of gases, finally bring about the plumbago stage.
What the action is which transforms plumbago or some other form of carbon into the condition of a diamond cannot be stated.
To prepare the filament the cellulose threads are cut into the proper lengths, bent into horseshoe shape, double loops, or any desired form, and then folded round carbon formers and immersed in plumbago crucibles.
In a speaking-telegraph transmitter, the combination of a metallic diaphragm and disk of plumbago or equivalent material, the contiguous faces of said disk and diaphragm being in contact, substantially as described.
It consists of a series of silk disks saturated with a sizing of plumbago and well dried.
It consumes very slowly in the fire, and deflagrates like plumbago with nitre.
Carbonaceous matter is rare in the true Eozoon limestones, and, as already stated, I would refer the Laurentian graphite or plumbago mainly to plants.
Sir William Logan states[D] that 'the deposits of plumbago generally occur in the limestones or in their immediate vicinity, and granular varieties of the rock often contain large crystalline plates of plumbago.
At Worcester, in the State of Massachusetts, 45 miles due west of Boston, a bed of plumbago and impure anthracite occurs, interstratified with mica-schist.
Plumbago has at various times formed quite an item in the exports of the island.
Besides precious stones, Ceylon produces gold, quicksilver, plumbago of the finest quality, and magnetic iron ore.
There are very old plumbago mines hereabouts, and a group of mouldering stone lions, elephants, and a figure designed to represent that fabulous creature, the unicorn.
Plumbago mining may not present the charm which attaches to the digging for rubies and sapphires, but in the long run the cash results are far more satisfactory.
The Colonial Blue Book shows that in 1840 there were only about one thousand hundredweight packages of plumbago or graphite exported from Ceylon.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "plumbago" in a variety of sentences. We hope that you will now be able to make sentences using this word.
