None
Or THE Use or SoLuBLE AnopEs.—In nearly all the indus- trial applications of electrolysis, the platinum or carbon anodes are replaced by soluble anodes; the result is to maintain the chemical neutrality of the liquors and to suppress the work necessitated by the decomposition. In the case of sulphate of copper, if the anode is a plate of copper, if will reeeive some oxygen and sulphurie aeid which 40 ELECTROLYSIS. will attack it and form some sulphate of copper which will be dissolved in the bath. If, therefore, the cathode increases in weight, the anode will decrease in the same proportion. The work of decomposition will be exactly compensated by that of recomposition, and the electrical energy will be expended only by the conductor and by some small secondary actions. Notwithstanding this arrangement, the liquor will, after a certain time, be subject to some changes in its degree of satura- tion; the sulphate will gradually decrease round the negative, and concentrate round the positive pole. The remedy for this want - of homogeneity in the body of the liquor consists in producing a continuous mechanical movement in the vat, so as to constantly mix all the parts which are in a state of dissolution. When treating of the refining of metals we shall have an opportunity of examining the work expended when soluble anodes are used, and we shall see that this work is far from being nil, The necessity of employing baths of very great resistance and to keep the electrodes at a certain distance from each other in order to obtain the metal in a state of absolute purity create considerable resistances which often absorb more than 2 volts. This comparatively large electromotive force has the incon- venience of producing decomposition of the water, which would not take place under 14 volt, and of constituting a very impor- tant waste of work. The phenomena of polarisation and of in- version of currents, which are so prejudicial to industrial electro- lytic operations, are also caused by the decomposition of the water. PRACTICAL DETERMINATION OF THE COUNTER ELECTRO- MOTIVE Force AND OF MerTatiic Resistances.—M. E. Marchese, an engineer of Genoa, who makes his speciality of the treatment of sulphide of copper by electricity, has quite recently published a note on the determination of the resistances of the circuit. We will consider its principal points. , The difference of potential. observed between the two elec- trodes of an electro-chemical bath arises out of the counter electromotive force which is necessitated by the dissociation of the electrolyte and of the electromotive force absorbed by the metallic resistances of every kind. In order to obtain an WORK ABSORBED IN ELECTROLYSIS. Al economical efficiency, it is useful to know the proportion exist- ing between these two electromotive forces, or, what amounts to the same, between their two corresponding resistances. The determination, by means of calculation, of these two quantities, is not an easy matter, as the chemical actions are often of a very complex nature, and the elements of the metallic resistance are extremely varied and subject to great alterations even during the course of a single operation. If the intensity C is measured in amperes, the fall of poten- tial E between the electrodes, in volts, the resistance evidently == Calling E’ the counter electromotive force, and R’ the metallic resistance of the bath, we shall have R’ = =. _ In the industrial practice and for every electrolyte, E’ can be considered as being constant, and R’ as variable, owing to the differences of heat, saturation, acidity, &c., which, although they may be slow in manifesting themselves, nevertheless occur with certainty for the whole duration of the operation. It can, however, be assumed that R’ is constant during a short interval of time. M. Marchese advises estimating E and C on the electrolyte which is under observation, then to alter the regimen by increasing or reducing the speed of the dynamo machine and make some new observations. Thus at a normal speed, we have, for example: E- Ff = = R. For a greater speed we obtain E+e-fE ; tata R. We deduce from these two equations: eet’ Cc Res ce AQ ELECTROLYSIS. - If, for example, EH = 0°9 volt and C = 150 amperes. we suppose that after the acceleration of speed we find: E + e =1°1 volt, from which e = 0°2 volt. C + ¢ = 250 amperes, from which c = 100 amperes. We shall have for the counter electromotive force: Be ak ¢ 150 ie, = 0°9 — 0:25, = 0°6 volt, and for the metallic resistance of the bath: ph EBD Se R = T00 = 0 002 ohm, If The resistance of the conductors and of the machine itself can be correctly ascertained ; it is therefore very easy to calcu- late the total resistance and the power required for the treat- ment of the electrolytic substances which it is proposed to separate. In order to obtain as high an economical result as possible, it will be useful to determine from time to time both the counter electromotive force which is developed between the electrodes and the metallic resistance of the bath. ( 43) CHAPTER IY. TABULAR DATA, Resistance of Metals and usual Alloys—Relative Conductivity of Metals— Influence of the Temperature on the Resistance of Metals and Pure Copper—Resistance of Pure Copper Wires and Bars—Conductivity of various Coppers—Resistance of various Saline Solutions—Resistance of various Acids—Chemical and Electro-chemical Equivalents—Heat De- veloped by the Formation of the principal Binary and Ternary Com- pounds—Motive Power required for the separation of various Metals from their Solutions—Limits of Electrolysis, Experiments of M. Berthelot. Resistance oF Meraus anp Usvat ALLoys AT 0° CENTIGRADE. (Matthiessen. Percentage of Resistance of a fone in Name of Metals. Nae era rag semaine per Observatidhs, degree centi- opposite faces. grade i Microhms. Silver, annealed .. 1°521 0°377 These figures, » hard-drawn . 1°652 = which have been Copper, annealed .. 1°616 0-388 published in the es hard-drawn 1°652 ia ‘Transactions of the Gold, annealed Y 2-081 0°365 British Association,” re hard-drawn ae 2°118 ba have been, until now, Aluminium, annealed 2°945 ae accepted without dis- Zine, pressed .. .. 5° 689 > cussion as the prac- Platinum, annealed 9°158 ad tical measures. Tron, annealed.. .. 9°825 0°630 Nickel, annealed 12°600 re Tin, pressed ., 13°360 0°365 Imicrohm = Lead, pressed .. .. rc 19-850 0°387 0:000001 ohm. Antimony, pressed .. “i 85-900 0-389 Bismuth, pressed ‘> 132°+700 0°354 Mercury, liquid pe 99°740 0°072 1 Silver, 2 Platinum 24°660 0°031 German silver .. 21°170 0°044 2 Gold, 1 Silver 10°990 0°065 44 ELECTROLYSIS. RELATIVE Conpuctiviry or METALS. CoMPARED TO SILVER AND PURE Copper. (Lazare Weiller.) Name of Metals. rere Observations. 1 Silver, pure; se ae cas ees 100 These experiments have 2. Copper, pure .. 100 been conducted with a series 3. Copper, pure, super refined and 99:9 of bars especially prepared crystallised ; for the purpose. These said 4, Silicium bronze (telegraphic) .. lee bars have been molten at a 5. Copper and silver alloy at 50 per cent.| 86°65) uniform diameter of about 6. Gold, pure .. 78 13 millimetres. They have 7. Silicic copper (with 4 per 100 of | silicon) 75 been cut so as to show the 8. Silicie copper ary 12 e, 100 of 54:7 grain of the metal, and the silicon) detached portions have then 9, Aluminium, pure ¥ 54°2 | been drawn into wires. 10. Tin, containing 12 per 100 of sodium | 46-9 It is on the wires so ob- 11. Silicium bronze (telephonic) .. 35 tained that the said experi- 12. Plombiferous COPD pe 10 ee 100 30 ments have been carried out oflead .. ” and of which the results are 13. Zine, pure .. 29°9 | given in the table. 14, Phosphor bronze (telephonic) .. ¥ 29 As regards those alloys 15. Silicium brass, with 25 per 100 of zinc | 26°49) which can neither easily be 16. Brass, with 35 per 100-of zinc. 21°15) drawn or rolled, such as cer- 17. Phosphide of tin.. .. 17°7 | tain phosphides or silicides, 18. Gold and silver alloy, 50 per e cent. . 16°12) the measurements have been 19. Swedish iron .. 16 | taken direct from the bars 20. Pure tin of Banca eas | Ses 15°45) according to the method of 21. Antimonous copper .. «» | 12°7 | Sir W. Thomson. 22. Aluminium bronze, 10 per 100 12°6 The measurements have 28. Siemens'steel .. 1.9 os es 12 been taken by means of a 24. Platinum, pure .. 10°'6 | Wheatstone bridge with a 25. Amalgam of cadmium, with 15 per 10:2 sliding index, a differential 100 ofcadmium ... z i galvanometer, and a battery 26. Mercurial bronze, Drosnier a3 10°14| of four cells. 27. Arsenical copper, Hiss 10 eet 100 on 9+] arsenic .. 28. Lead, pure .. 8°88 29. Bronze, with 20 per 100 of tin.. 8°4 30. Nickel, pure 7°89 31. Phosphor bronze, with 10 per 100 of tin} 6°5 82, Phosphide of copper, be 9 Re 100 4°9 of phosphorus .... 33. Antimony .. .. oo 3°88 INFLUENCE OF THE TEMPERATURE ON THE RESISTANCE OF METALS. (Matthiessen.) According to the formula R = r (1 + at + b?*). R resistance at ¢° ; r resistance at 0°; t centigrade degrees. Value of numerical coefficients a and ° for a few metals. Metals. Value of a. Value of b. Very pure metals .. 2% + 0:0038240 + 0:000001260 | Mercury (Gree i. ee A: + 0°0007485 — 0:°000000398 German silver i. + 0-0004433 + 0°000000152 Silver and platinum Bs + 0:°0003100 ae Silver and gold alloy + 0:0006999 — 0°000000062 a ae ek ee ee TABULAR DATA. Conpvettviry or Meras (Matthiessen), Coefficients for the temperature: ¢ in degrees centigrade. 45 Metals. Coefficients. Silver oe ee oe ee wee | OC = 100 — 0°38278 ¢ + 0-°0009848 #7 so ee ee wee we | O = 100 — 0°38701 t + 0°0009009 #7 se ee te ee oe we we | O = 100 — 0°86745 ¢ + 0°0008443 &* Zine .. «ee ee ws we Swe | © = 100 — 0°37047 t + 0° 0008274 &? Cadmium * * ** . - 0 = 1 00 —_ 0°36871 t oa 0°0007575 ? Tin ca * . * * -* * oC = 100 = 0°36029 t + 0:0006136 Fal Lead or -* * oa or 0 — 100 - 0°38756 t -f 0-0009146 t Arsenic .. .. 2s ee ee oe | © = 100 — 0°38996 t + 0°0008879 # Antimony . * ad - - ad © a 100 _— 0° 39826 t + 0° 0010364 e Bismuth * - . - -* * C = 100 _- 0° 35216 t + 0° 0005728 # Average .. | C = 100 — 0°37647 ¢ + 0°0008340 # INFLUENCE OF THE TEMPERATURE ON THE RESISTANCE AND THE CONDUCTIVITY oF Pure Copper. E 3 E g : Resistance. sc bE Resistance. wie EE Resistance. we 85. gs a3 aS aS aS 0 | 1:00000 | 1-00000 1 | 1°00381 | 0°99624 || 11 | 1°04199 | 0°95970 || 21 | 1°08164 | 0-92452 2 | 1°00756 | 0°99250 || 12 | 1°04599 | 0°95603 || 22 | 1°08553 | 0°92121 8 | 1°01135 | 0°98878 || 13 | 1:04990 | 0°95247 || 23 | 1°08954 | 0°91782 4 1:01515 | 0°98508 | 14 | 1°05406 | 0°94893 || 24 | 1°09356 | 0°91445 5 | 1°01896 | 0°98139 || 15 | 1-05774 | 0°94541 || 25 | 1°09763 | 0°91110 6 | 1:02280 | 0°97771 || 16 | 106168 | 0°94190 || 26 | 1:10161 | 0-90776 7 | 1:02663 | 0°97406 || 17 | 1°06563 | 0°93841 || 27 | 1:10567 | 0:90443 8 | 1°03048 | 0°97042 || 18 | 1°06959 | 0:93494 || 28 | 1:11972 | 0°90113 9 | 1°03435 | 0-96679 || 19 | 1°07356 | 0-93148 || 29 | 1-11382 | 0-89784 10 | 1°03822 | 0°96319 || 20 | 1:07742 | 0°92814 || 30 | 1-11782 | 0°89457 ReEsIsTANCE OF ANNEALED Pure Coprer WIRES AND Bars at 0° Cent. Diameter | Section in | Weight per | Length per ene: cd uare - etre In ogramme metres. | "metres. | Grammes, | "in Metres, | Obmeper | Metres per | Ohms per 0°5 0°1963 1°74 | 576°0 0-081 12°305 46°81 1:0 0° 7854 6°99 | 144-0 0°0203 48°872 | 2°95 1°5 1°7670 15°75 63-0 0-0091 109°75 | 0°574 2°0 3°1420 27°95 86-0 0°0051 195°15 | 0°185 2°5 4°9087 43°70 23°0 0°0032 808°60 | 0°0745 8°0 7: 0690 62°93 16°0 0°0023 439°10 | 0°0365 3°5 9°6214 85°67 11°7 0°00165 605-00 | 0°0193 4:0 12-566 111°9 8°94 0*00129 777°00 | 0°01150 4°5 15°900 141°8 7°05 0°001011 | 989-00 | 0-00713 5 19°630 174°0 5°76 0°000810 | 1231-00 | 0°00468 6 28°276 251°7 4:00 0°000580 | 1756°3 0°00232 * 88 +486 342°7 2°92 0°000412 | 2420°0 0°00120 8 50° 264 447°3 2°23 0°000321 | 8008-0 0000718 9 63°601 567°0 1‘76 0°000253 | 3956-0 0°000455 10 78°540 699°0 144 0°000208 | 4878°2 0000295 46 ELECTROLYSIS. RESISTANCE OF ANNEALED Purr Copper WIRES AND Bars—continued. Diameter | Section in’ | Weight per | Length per = in Milli- | Square Milli-/ Metre in Kilogramme | Qhms per Metres per Obms per metres. metres. Grammes. in Metres. Metre. Ohm. Kilogramme. Il 94°250 840°0 -| 1:20 0°000167 5854-0. |0° 000202 12 113-10 1007°0 0°993 |0°000145 7025°2.|0°000145 13 133°45 1190°0 0°847 |0°:000118 8293°0 |0°0001035 14 153°94 1371°0 0°730 |0°000103 9680-0 |0°0000750 15 176°70 1575°0 0°630 |0°0000910 | 10975-°0 0-0000574 16 201°04 1789°0 0°556 |0°0000804 | 12032-0 |0-0000449 17 227-70 2001-0 0°500 (0°0000692 | 14450-0 |0°0000346 18 254°41 2268°0 0°440 |0°0900632 | 15824-0 |0-0000278 19 283-32 2520°0 0°400 |0°0000556 | 17561-0 |0:0000227 20 314°20 2795°0 0°360 = |0°0000510 | 19515-0 |0:0000185 25 490°87 4370°0 0°230 (0:0000324 | 30860°0 |0°00000745 30 706°90 6293-0 0°160 |0:0000230 | 48907-0 \0:00000365 35 962°14 8567°0 0°117 = \0:0000165 | 60500°0 \0:00000193 40 1256°6 11184:0 0°0894 (0°0000129 | 77700-0 \0-000001150 45 1590-0 14175°0 0°0705 (0°00001011; 98900-0 \0:000000713 50 1963°0 17400°0 0°0576 (0°00000810) 123050°0 |0-000000468 ConpvocrTiviTy oF CoppER ALLOYED wiTH Foreign SupstTances. Pore Corper = 100. (Matthiessen.) Condueti- Condueti- Substances alloend wish: Lalas Tempera-|| Substances alloyed with vivnne Teeges Pure Copper. ared to Cent Pure Copper. pared to Cent. opper. - Copper. ° ° 0°5 perl00o0fcarbon .| 77°87 | 18°3 || 0°48 per 100 of iron ..} 35°92 | 11°2 0:18 » sulphur | 92-08 19°4 || 1°66 “A . 28°01 13°1 0°13 ,, phosphorus| 70°34 | 20-0 ||1°33 ,, tin 50°44 | 168 0:95 ,, ‘ 24°16 | 22:1 ||2:52 ,, e 33°93 | 17-1 2:5 7°52 | 17°5 ||4°9 * a 20°24 | 14:4 Copper with tr traces of] 69.98 | 19-7 {1-22 » silyer..| 90°34 | 20-7 2°8 per 100 of arsenic. 13°66 19°3 || 2°45 9 » --| 82°52 19°F 54 642 | 16°8 |\3°5 » gold ..| 67°04 | 18-1 Sd with traces of |) 93.41 | 19-0 || 10-0 » aluminium) 12°68 | 14:0 1°6 per 100 of zine . 79°37 | 16°8 ||0°31 » antimony - f 32 , 4 .. | 59°23] 10°3 llo29 ° aa 64°5 | 12°90 Rexative Conpuctivity or Copper or various Extractions. (Matthiessen.) Substances, nes pier 1. Spanish, from Rio-Tinto, with 2 per 100 of arsenic, traces 14: 24 “4-8 of lead, nickel, suboxide.. .. 2. Russian, "from Demidoff, with traces of arsenic iron, nickel : J suboxide ia; 59°34 | 127 33 Tough cake, extraction not. mentioned, with traces of ‘lead, 71:03 | 17:3 iron, nickel, antimony, suboxide ... 4, Best selected, extraction not mentioned, with traces of tomy) 81°35 | 14-2 nickel, antimony, suboxide .. .. 5. Australian, from Burra-Burra, traces of i iron and suboxide .. 88°86 | 14°0 6. American, from Lake Superior, traces of. pes gubondes 92°57 | 15-0 and 0-03 per 100 of silver pie forks: i in } TABULAR DATA, 47 IxFLveNce or THE SuBoxrpe. (Matthiessen.) a a Process of Preparation. oe ee Copper, pure} Oxide reduced by the ee ai ba .. | 98°00 | 18°6 a Galvanic copper not melted vi .. | 98°46 | 20°2 rah Copper of commerce, not gare .. | 98°02 | 18-4 % The same — melting in h Page Rs e 92°76 | 19°38 The same with a current of hy para rong, P i 7 the molten metal .. z bedi (I RemarKk.—The conductivity finerehiiee about 2°5 per 100 when the wires are annealed. Copper containing some suboxide, the proportion 2 : of wh hich has not been correctly determined . H 73°82 | 19°5 Galvanic copper, extracted from a dense ingot, | 93°3 | 12°8 melted under the coal and run in gas Copper from a porous ingot of the same metal as before, but run into a mould under sels 94°8 | 13 conditions .. .. Galvanic copper cemented ‘with ‘coal, and con- taining silicon bated traces of phosphorus and>| 62°8 | 13 SPORE sac ae REsISTANCE OF CERTAIN LiQuIns. Sodic Chloride (Sea Salt). Potassic Nitrate (Gelapetre). Weight contained in | Resistance in Ohms at Weight c contained in | Resistance in Ohms : at 100 Grammpes of Water. 18° Centigrade. 100 Grammes of Water. 18° Centigrade. 25°8758 0°38106 18-9167 0°53018 24°40338 0° 36917 13°7647 0°70436 20-9787 0°40647 10°4840 0°86019 17°0174 0°45275 6°6079 1-24140 10°4525 0°66172 4°3964 2°11790 6°0957 0*99070 1°5452 4°06427 3°6880 1-56940 1°7177 8°54370 Sprciric ResisTANCE or SotuTions oF SULPHATE OF CoprEr AT 10° CENTIGRADE, (Ewing and MacGregor.) Density. Specific Resistance. Density. Specific Resistance. 1°0167 164°4 1°1386 35:0 1°0216 184°8 1°1432 34:1 1:0318 98°7 1°1679 31°7 1°0622 59°0 1°1823 30°6 1:0858 47°3 12051 (saturated) 29°3 1°1174 38°1 Sprctric ResisTaNce or SoLutions OF SutPHATE oF Copper. (Fleeming Jenkin.) sp: nog yore rer ue | 16° | 20° | me | 280 | 30° 8 parts | Water: 100 parts 45°7 | 43°7 | 41°9 | 40°2 | 37°1 | 34°2 | 32-9 oa 100, | 36°3 | 34°9 | $3°5 | 32°2 | 29°9 | 27°9 | 27°0 a Re 100 , | 81:2 | 80°0 | 28°9 | 27°9 | 26°1 | 24°6 | 24-0 20; ;, 100 ,, | 28°5 | 27°5/| 26°5 | 25-6. | 24°1 | 22°7 | 22-2 rie 100 ,, | 26°9 | 25°9 | 24°8 | 23°9 22*2 | 20°7 | 20-0 28 Ci, 100 ,, | 24°7 | 23°4 | 22-1 | 21°0 18°8 | 16°9 | 16°0 48 ELECTROLYSIS. WIEDEMANN’s EXPERIMENTS (1856). Solution of Sulphate of Copper: SO3, CuO + 5 HO at 14° C, grammes. ohms. 31°17 grammes, or 19°95 anhydrous sulphate in one litre .- .. 124°3 62°34 : 39°90 . 3 ere ee 77°92 ff 49°87 59 se po es 59°9 93°51 A 59°85 ‘ : oe Hage!) ee 124-68 3 79°80 + = ais oe 45°7 155°85 9 99°75 os ¥s net tay 39°9 187°02 & 119°70 ‘3 * aes 36°3 Srrcrric Rusistanor or Sunpuurtc Aci SoLvutions. (Fleeming Jenkin.) Temperatures. Densities. 0° 4° go 12° 16° 20° 24° 28° 1°10 | 1°37} 1°17] 1°04 0:925 | 0°845 | 0°786 | 0°737 | 0°709 1°20 | 1°33 1°11 | 0°926| 0:°792| 0°666 | 0°567.| 0°486 | 0°411 1:25 | 1°31 | 1°09 | 0°896 | 0°743 | 0°624 |] 0°509 | 0°434 | 0°358 1°30 | 1°36 | 1°13] 0°94 0°79 0°662 | 0-561 | 0:°472 | 0°394 1°40 | 1:69 | 1°47 | 1°80 1:16 1°05 0-964 | 0:°890 | 0-839 1°50 | 2°74 | 2°41] 2°13 1:89 1°72 1°61 1°32. | 1°43 1°60 | 4:32 | 4°16 | 3°62 3°11 2°75 2°46 2°21 | 2°02 1:70 | 9°41 | 7°67 | 6°25 5°12 4°23 3°57 3°07 | 2°71 Sprciric Resistance oF SutPpHURIC Acip Soxiurions. (Matthiessen.) : ; Percentage of Temperature : Specific Gravity. SOP elg — in Gent grade. Resistance, ° 1:003 0:5 16°1 16°010 1:018 2°2 15°2 5°470 1:053 yh 13°7 1°884 1-080 12°0 12°8 1°368 1°147 20°8 ° 13°6 0-960 1-190 26:4 13°0 0°871 1°215 29°6 12°3 0°830 1°225 ‘80:9 13°6 0° 862 1-252 84°3 13°5 0°874 1:277 . 37°3 £ 0:930 1-348 45-4 17°9 0°973 1°393 50°5 14°5 1-086 1°493 60°6 13°8 1:549 1°638 OTT 14°3 2°786 1°726 81°2 16°3 4°337 1°827 92°7 14°3 5*320 Sreciric Resistance oF Nirric Actp (Density = 1-36). Temperature. 2° 4° | 8° 12° 16° 20° 24° 28° 1:94 | 1°83 | 1°65 | 1:50} 1°39] 1°30] 1°22] 1°18 TABULAR DATA, 49 ~ tai or So.uTions or Sea Sart ar 18° 0. (Matthiessen.) —— tg tN i i - - : a ry re ’ L, ia i‘ ody Sea Salt With an equal | With 2 Volumes | With 3 Volumes = Copper pare concentrated. | Volume of of Water. of Water. Conductivities .. 81°52 23°08 17°48 13°58 Sreciric ResisTaNce or vARIOUs Liqumps. Liquids, Resistance. ohms, pepe olare BE. eed aot ag ae ‘ 1-13 “ ubl oe a of water... os 2°16 ‘i 8°92 Sodie chloride WN aon es in 500’¢ gr. of water) ‘ 1°13 Scoble vont volume of water .. 2°91 Caicie chloride, en He re 04. 1°30 chloride 1°30 Zine chloride 2°14 CHEMICAL AND Exrorro-CHEmMIcaAL EQuivALENTS Equivalents, Lido. col Name of Substances. Symbols. Slsciro. by ap am Chemical.| (y mical. poi 5 we mgr. Hydrogen . Gao eae aa wa H 1 0°01036) 0°0375 uminium - ae Al 13°7 | 0°1425 | 0°5137 Antimony .. ce Ge Sb 122 1°2688 | 4°575 Arsenic .. “* ve As 75 0°7800 | 2°8125 Barium _... + z Ba 68°5 | 0°7124 | 2°5687 Bismuth os - Bi 210 2-184 7°875 Boron .. tight re B 11 0°1144 | 10-4125 Bromine eRe Pe Br 80 0° 832 3 Cadmium a ab eue Cd 56 0°5824 | 2-095 Calcium “ on Ca 20 0:208 0°75 Carbon " Py FF C 6 0°0624 | 02250 Chlorine pe pe Cl 85°5 | 0°3692 | 1°33812 Chromium a Or 26°2 | 0°2725 | 0°9825 Cobalt A pe Co 29°5 | 0°8068} 1-°1062 Copper ae Cu 81°8 | 0°83807 | 1-1925 Fluorine ve F 19 0°1976 | 0-7125 Gold .. “ Au 98-3 | 1:0228 | 38-6862 Iodine a I 127 1°8208 | 4°7625 Tron .. as Fe 28 0°2912 | 1°05 Lead .. se Pb 103-5 | 1°0764 |) 38-8812 Magnesium ee Mg 12*2 | 0°1269 | 0:4575 Manganese Mn 27°5 | 0°286 10312 Mercury Hg 100 1-036 3°75 Nickel Ni 29°5 | 0°3068 | 1-1062 50 ELECTROLYSIS. CHEMICAL AND Exrorro-CaEmMicaAL EQuivALENTS8s—continued, Equivalents. Weights decomposed Name of Substances, Symbols. Chemical, | Hlectro- by — ’ emieal.| Ghemicl.| ampere in mgr. grammes. Nitrogen as se es ¥ N 14 0°1456 | 0:5250 Oxyrens 5. ar! we Be O 8 0°0832 | 0°3 PANGAN. 55) es. Phew bes 3 Pd 53°2 | 0°5533 | 1°9947 Phosphorus exons ieee 2% P 31 0°3224 | 1°1625 PAA Na. Ghee, ee) see ee Pt 98°6 | 1°0254 | 3°6975 Bs 1 a i K 839°1 | 0°4066 | 1*4637 Selenium .. .. .. op Se 89°8 | 0°4139 | 1°4925 INGE: Sah. Gert wwe) Le ay ; Ag 108 1:1232 | 4°05 USUI og -4 Sng tg tea Ca Sams z Si 14 0°1456 | 0°5242 Sodium : Na 23 0°2392 | 0°8625 Strontium .. ne Sr 43°8 | 0°4555 | 1°6425 Sulphur 47 Ss 16 0°1664 | 0°6 LAN tenes? das. itive : Sn 59 0°6136 | 2°2125 Zine att Wee horses ° Zn 82°7 | 0°3401 | 1°2243 Wakee iss ee ee es” ee ; HO 9 0:09328| 0:03375 Acid, acetic xf : 0,H,O, 60 0°6240 | 2°25 » hitric (monohydrated) Pie NO,H 63 0°6552 | 2°3625 » hydrochloric (gas) - ce pine HCl 36°5 | 0°3796 | 1°3687 » chromic .. rete CrO, 50°2 | 0°5221 | 1°8825 » oxalic ee ; C,H,0, 90 0°936 | 3°375 » phosphoric (hydrated) -. PO,,3HO 98 1°0192 | 3°675 » sulphuric (monohydrated) 80,H 49 0:5096 | 1°8375 tartaric... cae s C,H,O,, | 150 1°56 5°625 Oxides of silver (proto) Fea AgO 116 1°2064 | 4°35 = copper (di) setae CuO 39°7 | 0°4129 | 1°4864 3)? pALOR CDEOKO). «sg “ieete os FeO 36 0°3744 | 1°35 « Der) Gs aren Fe,0, 80 0:832 | 8 » manganese (di) .. Seg MnO, 43°5 | 0:4524 | 1:6312 9» mercury (ay SH). Vaadanet HgO 108 1°1232 | 4°05 » Nickel.. MAB irises NiO 387°5 | 0°39 1°4062 ns: a SOAS <x 5 ie PbO, 119°5 | 1°2428 | 4°4812 kg ae? ee (anhydrous) os KO 47°1 | 0°4898 | 1°7662 ” NaO 31 0°3224 | 1°1625 ay og = ZnO 40°5 | 0:4212 | 1°5187 Ammonia .. .. |NH,O,,HO| 35 0°3640 | 1°3125 Argentic nitrate fan) Paar ee O,Ag 170 1°768 | 6°375 Chloride of ammonium .. .. .. | NH,Cl 53°5 | 0°5564 | 2°0062. POR 7s. Dev « | FeCl 63°5 | 0°6604 | 2°3812 + s» (per). ; 2+ 3 Hy- .. Chromicacid «. wu, ined Oo 103 | + 81/\14x3 Protoxide of iron (hydrated) .. Fe+0 36 + 84°5 Peroxide of iron s is Fe, + O, 80 |+31°9x3 Oxide of nickel fs ad i+0O 87°5 | + 30°7 » cobalt Bs is Co +0 87°5 | + 32-0 ” gold » or Au, a 0 221 baad 5°6 a zinc te Zn+0O+ Ho 49°5 | + 41°8 * cadmium FS Cd+0O 64 + 33°2 ry: » lead 7 Pb + O + HO| 120°5 | + 26°7 i= Protoxide of copper .. «.. « Cu, + O 71°4 | + 21°0. ey Dioxide of cr gg (hydrated) .. |Cu+O+ HO! 48°7/ + 19°0 - Protoxide of + ea Sn +0 67 + 34°9 : Dioxide of tin - Sn + O, 75 + 67°9 : Protoxide of mercury .._ .. Hg, +0 208 + 21:1 7 Dioxide of mercury (yellow) Hg +0 108 + 15°5 ; Oxideofsilver ... 0 os a Ag+0O 116 + 35 : Protoxide of platinum.. .. .. Pt+0O 106°6 | + 7°5 ‘ Oxide ofbismuth.. .. . .. Bi +0, 234 + 68:9 ; » antimonious (hydrated) ., Sb + O, 146 + 88°7 os Antimonicacid .... 1. Sb+0O, | 162 | 4114-4 : ForMATION OF THE PrincrpAL CYANIDEs. Heat Developed. Constituent niva- Hydrocyanic acid... .. «. Cy gas+H | 27 7°8 (gas)) + 13°1 Gvantde of potassium Sa?” eps Lue Cy+K 65:1 | + 67°6 | + 64°7 pa. sodium $4 ae oe Cy + Na 49 + 60°4 | + 59°9 ms ammonium - |\Cy+N+H,)} 44 + 40°5 | + 36-1 = zinc .. os Oy + Zn 58°5 | + 29°3 oe ug mercury «+ Cy + Hg 126 + 119 |) + 10°4 ‘ Silver) sc: oe cu fas +45 134 + 36 as pa mercury and potassium | Hg Cy + KCy| 191'1 | + 88 | + 6:2 = silver and potassium |AgOy + KCy/ 1991 | + 11°2 a & ho 52 ELECTROLYSIS. FoRMATION OF THE PRINCIPAL CHLORIDES. : ; Heat Developed. Namde. yma og sr nit a Se ements, ents. Solid State. nek Hydrochloricacid.. .. H+ Cl 36°5 |+ 22°0(gas)\+ 39°3 Chloride of potassium .. K + Cl 74:6 |+105°0 +100°8 ¥ sodium Na + Cl 58°5 |+ 97°3 + 96:2 “9 ammonium N+H,+Cl | 53°5 |+ 76°7 + 72:7 i lithium Li+ Cl 42°5 |4+ 93:5 +101-9 a calcium Ca + Cl 55°5 |-4+ 85:1 + 93°8 PR strontium .. Br + Cl 79°3 |+ 92°3 + 97°8 _ magnesium Mg + Cl 47°5 |+ 75°5 + 93°5 ms aluminium Al, + Cl, 132°9 |+ 53°6x3 |+ 79°3x3 es mene ENS Mn+ Cl 63 + 56:0 + 64:0 2 iron Fe + Cl 63°5 |+ 41:0 + 50:0 BS 4 (per) . Fe, + Cl, 162'5 |+ 32°0x3 |+ 42°6x3 se zinc .. Zn + Cl 68 + 48°6 + 56°4 “ cadmium ., Cd + Cl 91:5 |+ 46°6 + 48:1 3 lead Pb + Cl 139 |+ 42°6 + 39°2 - nickel Ni + Cl 65 {+ 37°3 + 46°8 fi cobalt.. «+ Co + Cl 65 + 38:2 + 47°4 ~ tin o. Sn + Cl 94°5 |-+4+ 40°2 + 40°6 ss » (bi) Sn + Cl, 130 |+ 64°6(liq.) |+ 78°7 aS gold . Au, + Cl, | 303°5 |4+ 22°8 + 27°3 ms copper (proto) . Cu, + Cl 98°9 |-+ 35°6 7 & a ; Cu + Cl 67°2 |+ 25:8 + 31:3 as mercury (proto) Hg, + Cl 235°5 |-+- 40°9 oF i 9 bi) Hg + Cl 135°5 |+ 31°4 + 29°83 9 silver . Ag+ Cl 143°5 |+ 29°2 ae s bismuth Bi + Cl, 316°5 |-+ 90°6 “fs antimony .. Sb + Cl, 228°5 |4+ 91°4 x Fe (per).. Sb + Cl, 299°5 |4104° 9(liq.) Protochloride of platinum and potassium .. Pt + Cl + KCl) 209:1 |+ 22°6 + 20°9 Bichloride of platinum and potassium .. .. «+ Pt + Cl, + KCl) 244°6 |4 44°7 + 42°3 ForMATION OF THE PrincipaAL Bromipes (Liquid Bromine).* Heat Developed. ianek Constituent Equiva- : _ Elements. lents. Solid State. — Hydrobromic acid H + Br 81 |+ 9°5(gas) |4+29°5 Bromide of potassium K + Br 119°1 |+96°4 +91:°0 sodium .. Na + Br 103. |4+86°7 +86°4 “= ammonium .. N+H,+Br} 98 /|+67:2 +62°9 “s aluminium .. Al, + Br, 267'4 |4+40°2x3 |+69°2x3. 4 ZANC\- ‘5 Zn + Br 112°5 |+39°1 +46°6 fe lead. Pb + Br 183°5 |4+34:5 +29°5 4 tin EAS oP Sn + Br, 219 |+50°7 +59°0 A copper .. Cu + Br 111°7 |417°4 +21°5 ss mercury Hg + Br 180 =|4+25°9 +24°5 3 silver .. Ag + Br 188 |+23°7 ae a gold Au, + Br, | 437 |+4+12°1 + 8:4 * Gaseous bromine liberates + 4°0 calories when being liquefied. TABULAR DATA. 53 Formation or THE Principat Ioprpes (Sou Tope). Heat Developed Constituent ulva- Names. Elements. ae Solid Sait, | Dissolved Salt. of potassium K+I1 166°1 +80°0 | + 74°7 sodium ‘ Na +I 150 + 68°8 | +70°1 ammonium N+H,+I1 | 145 + 50°6 | +47°1 aluminium Al, + I, 408°4 + 23°4 x 3|+53°0x3 a Se oy ae Zn +1 159-5 + 24°6 | + 30°3 ee ree Pbh+I 230°5 + 21°0 yy copper... Cu, +I 190°4 + 16°5 mereury (red) Hg +I 227 + 17:0 silver Sa ie Ag+I 236 + 14°38 gold (proto) . Au, +I 324 — 5:5 FoRMATION OF THE PRINCIPAL SULPHIDES. Heat Developed. Constituent niva- Names. Elements. = Solid Salt. Dissolved + Salt. Hydrosulphuric acid H+S8 17 |+ 2°3(gas) + 4°6 Sulphide of potassium K+S5S 55-1 +51'L | + 56°2 . * sodium Na+S 89 +442 | +51°6 a - ammonium N+H,+8 34 oe + 28-4 »' Pe esium Mg+S8 28 + 39°8 aA c = aluminium Al, + 8, 75 + 62°2 a 3: manganese Mn+8 43°5| + 22-6 2 ” iron Fe+8 44 | +11°9 = # zine Zn+8 48°5 | + 21-5 . - cadmium Cd +8 72 +17°0 % cobalt Co+S8 45°5 + 10°9 : nickel Ni+S 45°5 + 9°7 a lead Pb+S 119-5 + 89 * copper Cu+S8 47°5 + 51 a mercury Hg +8 116 + 99 - silver Ag+8 124 + 1:5 MisceLtLaANngous Meratiic Compounps. Heat Developed. Constituent uiva- Names. Elements. pr Solid State. Dissolved Hydruret of plutinum .... H + mPt /1+98°6m) + 8°7 Another do. os uses H + nPt |14+98-6n|} +17°4 ee Hg,, + K 24389°1 + 34°2 }| + 25°7 Amalgam of potassium 2+K 839°1 | + 29°3 >| dissolved Hg, + K(?) 839°1 + 16-0 in Hg Hg,, + Na 1223 + 21°6 }) +18°8 Amalgam of sodium ., &s + Na 823 + 21°1 }| dissolved Hg, +Na,| 746 +15°2x2}| in Hg 54 ELECTROLYSIS. FoRMATION OF THE PrincipAL METALLOID CoMPouNDSs. oe Equi Developed. mstituent uiva- ae. Elements. | lents. ROA Digsolved Ozone .. « « « «+ | 2(O40,) | 24x2|— 14°8x2(gas)| .. Dioxide of hydrogen (oxi- genated water) es “} H+0, if +300 Protoxide of nitrogen - | N+0 22 |— 10°3 (gas) ee Dioxide of nitrogen .. «.. | N+0O, 30 =|— 21°6 (gas) be Acid, nitrous .. .. N-+0, 88 |— 11°1 (gas) » hbyponitric .. N+0, 46 |— 2°6 (gas) is ae — 0°6 (gas) + 14°3 » nitric, anhydrous .. | N+0, 54 { + 1:8 (lig.) } 4+ 14-3 — 0-1 (gas) ee » » hydrated .. IN+0,+HO] 68 {lz 71da) | — 14s * » 2nd hydrate .. INO,H+4HO; 99 /|+ 5:0 (liq.) ad » hyposulphurous . |S,.+0,+HO| 57 oa + 33°6 5, sulphurous os 8+0, 82 |+ 34:6 (gas) + 38°4 z 45° oa » sulphuric anhydrous $+0, 40 { fi erie EW +105 e ee __}$0s-HO 49 |-+ 62:0 (lig. | + 70°5 bihydrated SO,H+HO | 58 /|+ 3:1 (liq.) = 8,+0 : » persulphuric .. 8,0,dissolved ee Baas i + Ys » hbypochlorous Cl+-0 43°5 |— 7:6 (gas) — 29 » chlorichydrated .. |\Cl+0O,+HO| 84:5 e - 12 » perchloric .. .. .. |C1L+0,+HO}| 100°5 |— 15:4 (liq.) + 4:9 » » &ndbydrate |C10,H+2HO) 118-5{/T eh ob ve ‘ » 8rdhydrate |ClO,H+4HO) 136°5 |+ 15-0 (sol.) Oxide ofcarbon .. .. «. | O+0 14 |+ 14:4 (gas) : Carbonic acid .. .. C+0, 22 = |+ 48:5 ; Sulphide of carbon .. O+8, 8 {- 57a) Silicigacid ... .. .. «. | Si+0, 30 | 109°6 (sol.) 103°7 . sys . : — 75°6 (gas) e Chloride of silicon .. Si+Cl, 85 { = 18-8 easy Organic Compounds, Acid, acetic . « (O,4H,+0, | 60 — |-+129-1 (sol.) +127°0 ” oxalic ee ee ee C,+H,+0, 90 +197 (sol.) +194°7 © » tartaric .. .. «. (O,+H,+0,.| 150 (+372 (sol.) +368°7 Se CIEEIOM «see ©O,,+H,+0,,) 192 (+354 (sol.) are TABULAR DATA. 55 Formation oF THe Ammon1acaL Compounns (Acid and base gaseous, unless otherwise specified). Names, Constituent Elements. Heat Developed. + 12°2 (gas) Ammonia . . . * N +H, 53 21°0 (dissolved) Hydrochlorate <a se) 6D HOl + NH. + 42°5 Hydrobromate .. .. « HBr + NH, + 45°6 Hydriodate - . . * HI + N oh 44°2 Hydrocyanate.. es HOy + + 20°5 Hydrosulphate .. .. «+ + + NH, + 23 wae Sulphate .. .. . | SOH+NH, | + 25°8 ( aizsolroa MON Tod) ae cae (ny ot 0,H,0, + NH, + 26°0 Nitrate . fe . * . NO H NH, ap 41°9 Oxalate * of Serres 4 0,H,0, +NH, | + 24:4 Bicarbonate ‘a 0,0, + H,O, + NH,;| + 30°4 * In the oxalate, the acid is taken in the hydrated state and solid. ForMATION OF THE Principat Sauts DissoLVED OR PRECIPITATED BY MEANS OF DISSOLVED AcIps AT ABOUT 15°, ¢| 4e i Names of the Bases, | Symbols. | ' 3 iz 3 aS ls - 2 oO = a — Bi < Fl a an A, SSO NaO 18°7 | 18°3 |14°3 15°85 |10°2 13°7 Potash “s KO 13°8 | 18°3 |14°3 15°7 10:1 13°7 Ammonia .. NH, 12°5 | 12:0 |12°7 14°5 5°38 12°45 Calcia CaO | 13-9 | 18-4 |18-5(pr.)|15°6 9°8(pr.)| 14°0 Baryta . | BaO | 13-9] 18-4 [16-7 |18-4(pr.)|11°1 13-85 Strontia. 2 SrO 13°9 | 13°3 |17 6 15°4 10°5 14°0 agnesia .. ..| MgO |18-°8| .. 156 |90 | 18-8 | pron: Aig } MnO | 11:7| 11:3 [14:3 [13-5 =| 6-8 =| 11°8 Protoxide of iron FeO 3 9°9 aa 12°5 5:0 10°7 aga bes oar - ee aa os as ae ee bp co t *“* “* * * hg * 1 ‘6 ” cadmium | CdO | 101] .. (to wo’ 110°. » zine ZnO 9°8 | 8°9 |12°5 11°7 5°5 9-8 » lead .. |PbOdilute| 7°7| 6°5 |12°8 10°7(pr.), 6°7 ae > copper.. | CuO | 75] 62) .. | 92 | 24 75 » mercury |HgO(prec.)) .. 3°0 | 7:0 e eo 9°45 Sa silver .. |[AgO(prec.)) 5°2 | 4°7 |12°9 7°2 6°9 ee umina, F ; ean ae 4 Al,0O, * , 10 5 a 9 8 uloxide oO . e .. ies hydrated 4Fe,0, | 5:9] 4:5] .. | 5:7 » | 59 uloxiade 0O .. pe oa i : 4 CEOy: Ve as os = | 82 ed ie 56 ELECTROLYSIS. ForMATION OF THE DissoLvED Saurs. Various Acids at about 15°. Names of the Acids. Symbols. Names or the | symbols. | pereioped. ( deg. C. Acid hydrofluoric... .. | HF dissolved | Soda dilute NaO /|+16°3 » nitrous .. NO,HO dilute | Ammonia (NH, dilute} + 8-8 Soda dilute NaO + 14:2 »» perchloric Cl0,, HO dilute |; Baryta dilute} BaO |+14'5 Ammonia /j|N&H, dilute) + 12°9 Soda dilute NaO [+ 9°5. » hypochlorous C10, HO dilute Baryta dilute! BaO + 9°8 » hyposulphurous .. | 8,0,HO dilute | Soda dilute NaO + 13°5 » Sulphurous .. SO, dissolved | Potash dilute KO + 15°9 s - «» « |2 80, dissolved “ KO +17°9 » hypophosphorous {PO, 3 HO dilute} Soda dilute NaO /|+ 15:2 ‘5 NaO + 14°8 »» Phosphorous .. |PO;,3 HO dilute L 2NaO | +28'4 % Peete —_, PO,, HO dilute - Nao |+14:5 Bok Cs NaO | +14°8 » Ba ated bi- \po,, 2 HO dilute r S eee Ps 2NaO | +  85°9 » arsenious AsO, dissolved 7 NaO + 13°8 ge > TE Al? © “4 2NaO |+ 15:1 » Silicic .. «- «. | SiO, gelatinous Ss $NaO |+ 2°15 » stannic... .. .. | SnO, gelatinous E NaO |+ 4°8 » chromic ie CrO, dilute *S NaO |+12°4 ms NaO + 12°7 » tartaric... .. «. |C,H,O,.dissolved 2 NaO + 12°6 TABULAR DATA, 57 Motive PowErR REQUIRED FOR THE ELECTROLYTICAL SEPARATION OF VARIOUS Merats from THER SaLive SoLurions. | Motive Power Motive Power 2 i] P required for the | required for the E z Decomposition of deppaiion of 1 Kilo-] ms | 1 Ki me of} gramme of the 3% 2° ‘the ectrolyte. Metal. as ee eee ie mat . 8 >) q . ti, be oui Kilogram- g Kilogram- BE 7 g Rs. g metres, ey metres. By Se 5 2" 3 s”| 5 Sulphate of “s36l 149,800 55] 875,700 139] 0-7i9 ‘ ulphate of copper ,800)/0°55 7: r ' _ . | Ohloride of copper 990} 197,6000-73) 419,800] 1°55| 0-645 Silver rem ext notans anide of im }{ 88) -11,470\0-04} 14,220) 0-05]18-900 Nitrate of Paver dis- s , c a, {solved in amnonin \ 81} 21,6800-08| 34,340 0°13] 7-700 ride of gold (with 5 A : Gold. { cyanide opotassinm)} 139] 38,1000-14| 58,700] 0-22) 4-600 Double hate of Nickel .. 3 nickel and ammo-'| 1,484] 289,600/0-89| 629,400] 2°33] 0-429 Double chloride of oy. | nickel and | 1,586} 805,3001-13] 671,700, 2-49] 0-402 nium oT Tin .. .. Protochloride of tin. 688} 182,100/0-67| 291,400! 1-08] 0-926 Lead .. | Acetate oflead.. .. | 820 86,600/0-32| 136,000| 0°51| 1-985 = Nitrate of lead . * act 882) 88,1000-33| 141,000| 0-52) 1-915 uble oxalate of zinc : Zi ; Zine. { cr nde teatgser Be; * 740} 183,800\0'50| 314,400| 1°16] 0-858 ~ a Preaias opsatclat ty 896] 211,600/0-78) 379,800] 1-41] 0-711 Mercury .. Cnonber bree 298} 93,200/0°35) 126,800) 0°47) 2-129 « orice of aluminium ~ .. Aluminium |{~"\nd ammonium }{ 8,680] 758,7002-81] 8,679,700)13-60| 0-073 Magnesium a 7,665] 831,100'3-08| 3,249,600|12-00| 0-083 Potassium* | Sulphate of potassium | 2,512} 477,600'1°77| 1,065,000] 3-95] 0-253 = Chloride of potassium | 2,584! 573,600/2-13| 1,094,000) 4°05) 0-247 Sodium .. | Sulphate of sodium .. | 4,063| 558,4002-07| 1,725,500| 6°39] 0-156 » «+ | Chloride of sodium .. | 4,183} 697,300\2-58| 1,773,200] 6°57| 0-152 Antimony |{* roy? Of Amt\! 749) 169,6000-63} 317,200] 1°17) 0-851 Double, chloride of iron ‘ , ‘ Irn. { and ammoniam ™ 1,785) 883,8001-24] 754,400, 2-79) 0-358 uble oxalate of iron ; :. * ; ott ‘mmonium " 584} 96,2000°36| . 247,800] 0-92! 1-091 : oride of platinum j : Platinum “crit cyanide _ i) } 209] 65,5002°48} 88,616, 033] 3-050 ater acidulated wi ® : ‘ Hydrogen { sulphate acid a Wa 02/14,626,800/54°18) 0-0184 * The metal is supposed to be in a free state. + Same observation, 58 ELECTROLYSIS. Limits or Evecrro.ysis (Summary oF M. BerrHenor’s EXPERIMENTS). : ee | Separated Substances. = er the sere Designation of $ raldacd Substances and ; Z | ra § eg g Observations. Symbols, To the Positive Pole, | 7° i ee $8 las8 A Ps @ mH |Se e588 SS g\Ee8 cal, : 1. SO,H dilute+O | KO dil.+H |—50:2) 51:5} 46 In these experiments, elec- 2. Positive pole of KO dilute ao Sppatenk cheer a - ORD. di son \ 22 | 24°5) 19 | trodes an short pagers Sulphate of UW 3 dilu i gel ess otherwise specie ; 3. Positive pole of Ko ia ed potassium |{*".~ ~ ; \ \43 * ‘ie The decomposition occurs zine: ZnO,SO, dil. ithout the battery. aig 4, poliilee pole of ogative vagwess 2 platinum : SO,H pole of kK. —72°3| 73°5| 68 The electrolysis occurs at \ dilute + O cury : the inferior limit but without ay the formation of an amal- Jan eanoetail } SO,H dilute + 0 eae seine H | 50 | 54 | 46 same ects podialeny a 1. SO, dilute + O —53°5| 57 | 51-5)" Hydrogen is at first liber- Sulphate of }!9" Positive pole of]| ated, Z SO copper: Zn —24°5|) 24°5) 24°5) Is explained by some dif- cit ae Cuoso, dilute ferences of concentration. Sulphate of |\ s0,H dilute + O Ca = |—45-1| 46 | 38 pig of \ SO,H dilute + O Cu —|—28-2} 32-5] 27 Chloride of |(Cl dissolved with KO dilute {|—46 | 46 | 40°5| |, Haloid salts: decomposi- potassium |{ the formation of va- +H to ego gp pando fe ne KCl . |{_rious compounds —47 remark applies to the de- Bromide of Br dissolved with KO < dilute composition of all the haloid potassium |} the formation of a 7a \ —41°5) 40 | 40 | Salts in general. KBr __.. |} perbromide Fluoride of potassium FH dilute + O { a eas } —51 | >51) 51 (a ea Todide of po- be on ‘ feasinn Kerf I { } —27 | 27| 245 Sats THE METALS OF WHICH OFFER SEVERAL DEGREES OF OXIDATION. Ferrous sul- ba make FeO. at} . Fe —32 | 32°5) 27 3? 2 % PhateFeSO,/l9, 80,H dilute+0 | FeO +H |—47 | 57-0] 49 | 23, this 2nd case the pro- Manganous : Mn0, + 80,H H —37 | 38 | 27 | continues, Iph In this 2nd case M 2 ane - es dilute } Mn |—60-9| 62°5| 57 tines to be deposited au ata anode. CASE OF THE POLARISATION OF THE ELECTRODES. sai With all th bstances, Nitrate of . NO,H dilute KO tee . OF | 2t the réactoa es, uae, potassium uu (H absor e O stopped by. the momentary KNO, .. O by the acid)}|—16 ney ll a nee oF a bapririg. oe ee 0; € Cure . t f th I i Sulphate of mabey Pion VES resumption. ammonium ; $0,H dilute + O. nt thewas to }| 88 | 24°5 : Aatepoai nianoctely oeee ba NH,SO,.. monia) —35 is not resumed after the con- Acetate of 0,H eB 0,0. ae NaO dilute} tact of the electrodes. sodium O:Hg aa + HO & +H —38 | 38 | 35 C,H,NaO, | ~ — ea ( 59) SECTION II. SOURCES OF ELECTRICITY. CHAPTER V. BATTERIES. Hydro-electric Batteries in Electro-chemistry —Becquerel Cell—Daniell Cell —Simple Bath—Balloon Cell—Thomson Cell—Callaud Cell—Meidinger Cell—Bunsen Cell—D’Arsonval Cell—Duchemin Cell—Leclanché Cell— Oxide of Copper Cell—Smee Cell—Noé Thermo-electric Battery—Clamond Thermo-electric Battery. Hypro-ELEcTRIO BATTERIES IN ELEcTRO-CHEMIsTRY.—The hydro-electric batteries mostly used in electric operations are - those of Daniell, Bunsen, and like inventors. For thin deposi- tions, and especially when the work is intermittent, Leclanché, Lalande and Chaperon’s cells can be used, as also generally all cells having the property of giving a regular current for a long time without wasting when not at work. 