OAO 0B0  OcO See also:

• ODO

ODO pep OFO a b ------------------ (ti) ja~~~E -0 a WI 0 0 0 Gal, . 0 and when made as directed below it has at t° C. an electromotive force E, volts, such that E =1.0184 -0.0000406 (t -20) -0.00000095 0—20)2 + 0.00000001 (t-20)3 . After the See also:

• PLATINUM [symbol Pt, atomic weight 145.0 (0=16)]

platinum wires have been sealed through the See also:

• GLASS
• GLASS (O.E. glees, cf. Ger. Glas, perhaps derived from an old Teutonic root gla-, a variant of glo-, having the general sense of shining, cf. " glare," " glow ")
• GLASS, STAINED

glass, a little aqua regia is placed in the See also:

• CELL (from Lat. cella, probably from an Indo-European kal —seen in Lat. celare, to hide; another suggestion connects the word with Lat. cera, wax, taking the original meaning to refer to the honeycomb)

cell legs until bubbles pi See also:

• GAS

gas arise from the platinum, when it is thrown out and replaced by a See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution of mercurous nitrate . Then, by the use of another piece of platinum as anode, See also:

• MERCURY
• MERCURY (MERCU1uus)
• MERCURY (symbol Hg, atomic weight = 2oo)

mercury is electrolytically deposited upon the platinum, which may also be amalgamated by making it See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white hot in a See also:

• BUNSEN, CHRISTIAN CHARLES JOSIAS, BARON VON (1791-186o,)
• BUNSEN, ROBERT WILHELM VON (1811-1899)

Bunsen See also:

• FLAME (Lat. flamma; the root flag- appears in flagrare, to burn, blaze, and Gr. d, XEryew)

flame and plunging it in mercury . To prepare the See also:

• CADMIUM (symbol Cd, atomic weight 112.4 (0=16))

cadmium See also:

• AMALGAM

amalgam, one See also:

• PART

part of pure cadmium is dissolved in six parts of pure mercury, and the product while warm and fluid is placed in one See also:

• LIMB

limb of the cell and warmed, to ensure perfect contact with the platinum See also:

• WIRE (A.S. wir, a wire; cf. Swed. vire, to twist, M.H.G. wiere, a gold ornament, Lat. viriae, armlets, ultimately from the root wi, to twist, bind)

wire . The cadmium sulphate solution is prepared by digesting a saturated solution of cadmium sulphate with cadmium hydroxide to remove See also:

• FREE

free See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid, care being taken not to raise the temperature above 7o° C., and then by digesting it still further with mercurous sulphate until no more precipitation occurs . The cadmium sulphate solution must be saturated and have free crystals of the See also:

• SALT (a common Teutonic word, cf. Dutch zout, Ger. Salz, Scand. salt; cognate with Gr. &Xs, Lat. sal)
• SALT, SIR TITUS, BART

salt in it . The mercurous sulphate must be free from acid, and made neutral by trituration with finely divided mercury . In making the See also:

• PASTE (O. Fr. paste, modern pate, Late Lat. pasta, whence also in Span., Port. and Ital., from Gr. 1r&vrrl or 1raara, barley porridge, or salted pottage, ir&ao'ety, to sprinkle with salt)

paste, so much cadmium sulphate must be added that a saturated solution of that salt is formed and is See also:

• PRESENT

present in the cell . The cell has the electromotive force above stated if the amalgam of cadmium has from 6 to 13 parts of mercury to 1 of cadmium . The See also:

• GERMAN
• GERMAN, DUTCH AND SCANDINAVIAN

German investigators seem to have a See also:

• GREAT

great preference for the H See also:

• FORM (Lat. forma)

form of cell, but it is clear that a narrow tubular cell of the See also:

• BRITISH

British See also:

• BOARD (O. Eng. bord)

board of See also:

• TRADE (O. Eng. trod, footstep, from tredan, to tread; in M. Eng. the forms teed, trod and trade appear, the last in the sense of a beaten track)
• TRADE, BOARD OF

trade form not only comes more quickly to the temperature of the See also:

• WATER

water See also:

• BATH
• BATH, THOMAS THYNNE
• BATH, WILLIAM

bath in which it is placed, but is more certain to be wholly at one temperature . In a modification of the H form devised by F .

E . See also:

• SMITH
• SMITH, ADAM (1723–1790)
• SMITH, ALEXANDER (183o-1867)
• SMITH, ANDREW JACKSON (1815-1897)
• SMITH, CHARLES EMORY (1842–1908)
• SMITH, CHARLES FERGUSON (1807–1862)
• SMITH, CHARLOTTE (1749-1806)
• SMITH, COLVIN (1795—1875)
• SMITH, EDMUND KIRBY (1824-1893)
• SMITH, G
• SMITH, GEORGE (1789-1846)
• SMITH, GEORGE (184o-1876)
• SMITH, GEORGE ADAM (1856- )
• SMITH, GERRIT (1797–1874)
• SMITH, GOLDWIN (1823-191o)
• SMITH, HENRY BOYNTON (1815-1877)
• SMITH, HENRY JOHN STEPHEN (1826-1883)
• SMITH, HENRY PRESERVED (1847– )
• SMITH, JAMES (1775–1839)
• SMITH, JOHN (1579-1631)
• SMITH, JOHN RAPHAEL (1752–1812)
• SMITH, JOSEPH, JR
• SMITH, MORGAN LEWIS (1822–1874)
• SMITH, RICHARD BAIRD (1818-1861)
• SMITH, ROBERT (1689-1768)
• SMITH, SIR HENRY GEORGE WAKELYN
• SMITH, SIR THOMAS (1513-1577)
• SMITH, SIR WILLIAM (1813-1893)
• SMITH, SIR WILLIAM SIDNEY (1764-1840)
• SMITH, SYDNEY (1771-1845)
• SMITH, THOMAS SOUTHWOOD (1788-1861)
• SMITH, WILLIAM (1769-1839)
• SMITH, WILLIAM (c. 1730-1819)
• SMITH, WILLIAM (fl. 1596)
• SMITH, WILLIAM FARRAR (1824—1903)
• SMITH, WILLIAM HENRY (1808—1872)
• SMITH, WILLIAM HENRY (1825—1891)
• SMITH, WILLIAM ROBERTSON (1846-'894)

Smith, of the See also:

• NATIONAL

National See also:

• PHYSICAL

Physical Laboratory (Phil . Trans., A, 207, pp . 393-420), a contraction formed in the See also:

• SIDE
• SIDE (mod. Eski Adalia)

side of the See also:

• VERTICAL (from Lat. vertex, highest point)

vertical See also:

• TUBE (Lat. tuba)

tube tends to hold the contents in See also:

• PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place . Fig . 4 shows this cell, hermetically sealed, mounted in a See also:

• BRASS
• BRASS (O. Eng. braes)

brass See also:

• CASE
• CASE, JOHN (d. 1600)

case . In cases when great accuracy is not required, a See also:

• DANIELL, JOHN FREDERIC (1790-1845)
• DANIELL, THOMAS (1749–1840)

Daniell cell can be used as a See also:

• STANDARD
• STANDARD, BATTLE OF THE

standard of electromotive force . The form designed by J . A . See also:

• FLEMING, PAUL (1609-1640)
• FLEMING, RICHARD (d. 1431)
• FLEMING, SIR SANDFORD (1827- )
• FLEMING, SIR THOMAS (1S44-1613)

Fleming (Phil . Mag., 20, p . 126) consists of a U tube, one See also:

• LEG
• LEG (a word of Scandinavian origin, from the Old Norwegian leggr, cf. Swed. lagg, Dan. laeg; the O. Eng. word was sceanca, shank)

leg of which contains a See also:

• ROD (O.E. rodd, probably related to Norw. rudda, stick, rodda, stake)
• ROD, EDOUARD (1857-1910)

rod of pure amalgamated See also:

• ZINC

zinc, and the other a rod of freshly electrotyped See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper .

The legs are filled with solutions of zinc sulphate and copper sulphate, the zinc rod being in the zinc sulphate and the copper rod in the copper sulphate . When so made, the cell has an electromotive force of 1.072 volts and no sensible temperature variation . The solutions are made by dissolving the purest recrystallized sulphate of copper and sulphate of zinc in distilled water . For the zinc solution, take 55.5 parts by See also:

• WEIGHT

weight of crystals of zinc sulphate (ZnSOa7OH2) and dissolve in 44.5 parts by weight of distilled water; the resulting solution should have a specific gravity of 1.200 at about 2o° C . For the sulphate of copper solution, take 16.5 parts by weight of pure crystals of copper sulphate (CuSO4,5OH2) and dissolve in 83.5 parts by weight of water; the resulting solution should have a specific gravity of 1.100 at 20° C . The solutions should be adjusted exactly to these densities and kept in stock bottles, from which the reservoirs of the cell should be filled up as required . A form of See also:

• POTENTIOMETER

potentiometer employing a vibration See also:

• GALVANOMETER

galvanometer and suitable for alternating current measurement by null methods has been devised by Dr Drysdale (see Proc . Phys . See also:

• SOC

Soc . Lond . 1909, 21, 561.) See J . A .

Fleming, Handbook for the See also:

• ELECTRICAL
• ELECTRICAL (or ELECTROSTATIC) MACHINE

Electrical Laboratory and Testing See also:

• ROOM

Room, vol. i . (See also:

• LONDON

London, 1903)-vol. i contains on pp . 108-110 an extensive See also:

• LIST (O.E. lisle, a Teutonic word, cf. Dut. lust, Ger. Leiste, adapted in Ital. lista and Fr. lisle)
• LIST, FRIEDRICH (1789-1846)

list of various See also:

• ORIGINAL

original See also:

• MEMOIRS

memoirs published on the See also:

• CLARK, FRANCIS EDWARD (1851- )
• CLARK, GEORGE ROGERS (1752—1818)
• CLARK, JOHN BATES (1847— )
• CLARK, JOSIAH LATIMER (1822—1898)
• CLARK, SIR ANDREW
• CLARK, SIR JAMES (1788—1870)
• CLARK, THOMAS (1801—1867)
• CLARK, WILLIAM (1770-1838)
• CLARK, WILLIAM GEORGE (1821—1878)

Clark and See also:

• WESTON, THOMAS (1737-1776)

Weston cells; G . D . Aspinall See also:

• PARR
• PARR, CATHERINE (1512-1548)
• PARR, SAMUEL (1747-1825)
• PARR, THOMAS (c. 1483—1635)

Parr, Electrical See also:

• ENGINEERING

Engineering Measuring See also:

• INSTRUMENTS

Instruments (London, 1903) ; W . C . See also:

• FISHER
• FISHER, ALVAN (1792–1863)
• FISHER, GEORGE PARK (1827-1909)
• FISHER, JOHN (c. 1469-1535)
• FISHER, JOHN ARBUTHNOT FISHER, 1ST BARON

Fisher, The Potentiometer and its Adjuncts (London, 1906) .