FILTER, or FILTRE, in Chemistry, &c. a piece of woollen cloth, linen, paper, or other matter, some of which are in the form of hollow inverted cones, used to filtrate or strain liquors through. The filtre has the same use and effect with regard to liquids that the sieve or seance has in dry matters.
Filters are of two sorts. The first are simple pieces of paper or cloth, through which the liquor is passed without farther trouble. The second are twisted up like a skain or wick, and first wetted, then squeezed, and one end put in the vessel that contains the liquor to be filtrated: the other end is to be out, and hang down below the surface of the liquor; by means hereof the purest part of the liquor distills drop by drop out of the vessel, leaving the coarser part behind. This filter acts as a syphon.
Water is freed from various impurities by means of basins made of porous stones, which vessels must be peculiarly beneficial in long voyages, and even upon land they are of considerable benefit, when none but stagnant waters are to be found, or springs issuing through clay.
A patent was granted in 1790 to a female potter, for inventing a composition to make filtering basins, as a succedaneum for that porous stone which is not every where to be found. She took four out of nine equal parts of tobacco-pipe clay, and five out of nine equal parts of sea, river, or pit sand, which she used for making small basins sufficient to contain one gallon of water. Her next proportions were equal parts of sea, river, or pit sand, and tobacco-pipe clay; her third proportions were three out of nine equal parts of tobacco-pipe clay; one out of nine equal parts of Stourbridge clay, or one out of nine equal parts of Windsor or other loam: and her fourth proportions were four out of eight equal parts of the burnt ground clay of which crucibles are made.
A patent was also granted to Mr Joshua Collier of Southwark, for a most ingenious method of filtering and sweetening water, oil, and every other liquid. The following is the contrivance, which combines the application of machinery with the antiseptic properties of charcoal.
Fish oil is one of the liquids which he had particularly in view, to free it from every thing disagreeable, either in taste, smell, or colour, to accomplish which he poured a quantity of oil into a convenient vessel, heated to the temperature of 120° of Fahrenheit's thermometer, adding caustic mineral alkali of the specific gravity of 1.25. He then agitated the mixture, afterwards allowing it to stand till the sediment subsided; and then drew it off into another vessel, with a sufficient quantity of burnt charcoal finely powdered, and a small quantity of diluted sulphuric acid, to decompose the saponaceous matter still suspended in the oil, when the oil became
Filter. came clear at the surface. He then agitated the contents of this vessel, and left the coaly, saline, and aqueous particles to subside; afterwards passing it through proper strainers, when it became quite transparent and fit for use.
The principle of the improved filtering machines consists in combining hydrostatic pressure with the mode of filtering per osenum, which procures the peculiar advantage of causing the fluid and its sediment take opposite directions. The filtering surface remains the same, while the dimensions of the chamber in which the sediment is received may be varied. To adapt the machines to every purpose for which they are intended, chambers must be provided of various capacities, for the precipitated matter. The space required is very great with respect to the oil trade, and as all dimensions will be required occasionally, no particular limits can be fixed. For distilleries and breweries they may be smaller in proportion, and a very small chamber will be sufficient for domestic economy. If water is to be freed from noxious particles, it must be made to pass through an iron box in its way to the filtering chamber, and the box must contain charcoal finely powdered. The water is received into this box and delivered by two apertures, which are opened and closed by cocks.
Another part of the invention consists in filtering machines in the form of stills, in which charcoal may be repeatedly burnt after any fluid substances have passed through it, for the purpose of freeing them from noxious particles, or discharging their colouring matter.
To the filtering apparatus of Mr Collier, instruments are attached for discovering the comparative qualities of oils, which depend in some measure on their specific gravities; spermaceti oil, when compared with fish oils being as 875 to 920. To do this, a glass vessel of any shape most convenient is employed, with a glass bubble, and a thermometer. If the oil is pure, the bubble sinks, when the mercury rises to a particular standard. When spermaceti oil is impure, the bubble floats, though of the temperature required.
To determine the tendency of oils used for burning to congeal in cold weather, a freezing mixture may be put into a phial of thin glass, into which let a thermometer be immersed, and a single drop of the oil permitted to fall on the outside of the vessel, where it will instantly congeal. As the cold produced by the mixture decreases, let the temperature be observed by the thermometer at which the oil becomes fluid, and runs down the side of the glass.
The following is a short description of the apparatus contrived for this purpose. A (fig. 1. Plate CCXVII.) is the cistern, into which the water or other liquor to be filtered is put. B B, is a tube opening into the bottom of the cistern A, and bent along the bottom of the machine conveying the fluid into C C C the filtering chamber, which is covered with leather bound down round its circular rim, and through which leather the water is percolated. D D, The basin rising above the level of the chamber and receiving the filtered liquor. E, The spout by which it runs off into a pitcher or other vessel. F, Another spout furnished with a cock to draw off the foul water from the chamber when necessary. G G G, The air tube, which begins above the level of the chamber, is covered with a button,
Filter. which saves the leather from being cut, and has a small lateral aperture for the air to be carried off. This pipe passes along the bottom and up the side, and rising above the level of the water in the cistern, is there closed, except a small lateral aperture through which the air escapes. H, A guard or rim with cross bars put over the leather to keep it from being forced up by the water. It is fastened down by means of two notches on opposite sides of the ground, by which it locks into two staples rivetted into the bottom of the basin. I, The lid sliding down to cover the water from dust, and suspended at pleasure by means of K K, two springs on each tube for that purpose. L M N O, A cylindrical box containing charcoal, which is connected with the above by means of the tube P, and a continuation of the tube B. L M, The water tube B continued below the charcoal apparatus, so that the fluid may pass through the same into the cylinder, from whence it enters the chambers at P, so as to be filtered through the leather as before described. R R, Collars which may be unscrewed at pleasure, so as to detach the charcoal apparatus whenever the charcoal requires to be purified by heat. S S, Two cocks to direct the fluid through the charcoal cylinder or immediately into the filtering chamber.
Fig. 2. A, A tub or cistern containing the oil to be filtered, and supplying a tube of sufficient height for the hydrostatic pressure to operate. B B, A main tube of wood, tin, leather, or cloth, to which any number of bags, C C, of the size and shape of corn sacks, or any convenient size or shape, may be connected. These are bound to D D D, straight double iron bars, furnished with a hinge at one end and a screw at the other, by opening which the bags may be emptied. F, A trough underneath, made to receive the filtered oil from the receivers E E E.
Fig. 3. A, A funnel, cask or cistern, into which the fluid is put which passes down. B, A tube fitted into the same, through which it enters. C, An iron still, or still of any other substance capable of sustaining heat, full of finely powdered and sifted charcoal, through the head of which the fluid passes into any receiver. D, A fire-place of any construction to drive over the fluid remaining interpersed among the charcoal, and also to purify the charcoal by an increase of temperature when required. E, A cock to let water into the flues to cool the apparatus for a subsequent operation.
Fig. 4. The trial glass with its thermometer.
FILTER is also a charm, supposed to have a virtue of inspiring love. The word is derived from φιλέειν, which signifies the same thing, of φιλέω, ἀμο, "I love."
The Greeks, when their love was without success, had several arts to procure the affections of their beloved. The Thessalian women were famous for their skill in this as well as other magical practices. The means whereby it was effected were of divers sorts; it was sometimes done by potions called φιλέειν, which are frequently mentioned in authors of both languages. Juvenal speak thus:
Hic magicus affert cantus, hic Thessala vendit
Philtra, quibus valeant mentem vexare moriti.
Their operations were violent and dangerous, and commonly deprived such as drank them of their reason.
Rules for Arts.
FIRE PLACE.
Plate CXXVII.
1. 1. 1. 1.
1. 1. 1. 1.
1. 1. 1. 1.
Prop 14 is all over 16
15 Dealtry
(341 29) 1 in 7th Sectn.
Three cases; hall ceiling on
9th; Warehouse; Woodhouse
Egn to orbit in fixed space
1. 1. 1. 1. 1. 1. 1. 1.
1. 1. 1. 1.
I may always
rep = o when body is in ant
two cases in manure
taylor Keorne
Vanishing fractions
Fig. 2.
Fig. 4.
Fig. 6.
came clear at the surface. He then agitated the contents of this vessel, and left the coaly, saline, and gummy particles to subside; afterwards per strainers, when it became fit for use.
which saves the leather from being cut, and has a small lateral snot
to be carried off. This is carried off up the side, and r
The principle of the impro consists in combining hydrostatic of filtering per ascensum, which advantage of causing the fluid anposite directions. The filterin same, while the dimensions of the sediment is received may be varie chines to every purpose for whi chambers must be provided of the precipitated matter. The si great with respect to the oil trade, will be required occasionally, no be fixed. For distilleries and br smaller in proportion, and a very si sufficient for domestic economy. I from noxious particles, it must be an iron box in its way to the filteri box must contain charcoal finely po is received into this box and deliver which are opened and closed by ec
Another part of the invention machines in the form of stills, in be repeatedly burnt after any fluid fed through it, for the purpose o noxious particles, or discharging ter.
To the filtering apparatus of M are attached for discovering the of oils, which depend in some me gravities; spermaceti oil, when co being as 875 to 920. To do this, shape most convenient is employed, and a thermometer. If the oil is sinks, when the mercury rises to a p When spermaceti oil is impure, the bul of the temperature required.
To determine the tendency of oils use to congeal in cold weather, a freezing mi put into a phial of thin glass, into which le meter be immersed, and a single drop of the mitted to fall on the outside of the vessel, whi instantly congeal. As the cold produced by ture decreases, let the temperature be observed thermometer at which the oil becomes fluid, and down the side of the glass.
The following is a short description of the appara contrived for this purpose. A (fig. 1. Plate CCXVI. is the cistern, into which the water or other liquor to l filtered is put. B B, is a tube opening into the bottom of the cistern A, and bent along the bottom of the machine conveying the fluid into C C C the filtering chamber, which is covered with leather bound down round its circular rim, and through which leather the water is percolated. D D, The basin rising above the level of the chamber and receiving the filtered liquor. E, The spout by which it runs off into a pitcher or other vessel. F, Another spout furnished with a cock to draw off the foul water from the chamber when necessary. G G G, The air tube, which begins above the level of the chamber, is covered with a button,
Rule for Act.
always correct; & no Lms;
put T-d for Am of 4th Sectn
A-d does not & A
180°; 37th propm 23 Pm
Taylor theorem; maxims &
minims; Steinberg's fraction
Page 161. Dealtroy
analytical; new of Leibniz
proof; Robinson's Srgt.
Kells centrifugal feed mill
machine; 1 Eqn; last year's Hg.
Remill's in Divn & fr.
Get by heart the three
cases. Mr. Smith's Newton's Expts.
Romilly's Newton's Expts.
Mr. & Mrs. by way about deducing
from eg. 1st & 2nd. Robt.
Germ's Cory, functions in 9th
Newton's Area A.B.P.D
infinitesimals
Expressions in Conic Sections
etc. in cycs;