FORMIC ACID; (Acide Formique, Fr.; Ameisensäure, Germ.) exists in the bodies of wood ants, associated with the malic or acid of apples. The artificial formation of this animal secretion, is one of the most remarkable triumphs of modern chemistry. If 10 parts of tartaric acid, 14 of black oxide of manganese, 15 of concentrated sulphuric acid, and from 20 to 30 of water be mixed and distilled in a retort, formic acid will be the liquid product; while carbonic acid will be disengaged. It may also be generated from other mixtures. This acid is transparent and colourless, of a pungent sour smell, a strongly acid taste, of specific gravity 1·1168 at 60° F., and may be re-distilled without suffering any change. It contains in its most concentrated form 193⁄4 per cent. of water. The dry acid, as it exists in the formiates, is composed of 32·54 carbon, 2·68 hydrogen, and 64·78 oxygen; or of two volumes carbonic oxide gas, and one volume of vapour of water. It reduces the oxides of mercury and silver to the metallic state. It has not hitherto been applied to any use in the arts.
FORMULÆ, CHEMICAL, are symbols representing the different substances, simple and compound.
| Name. | Formula. | Oxygen
= 100. | Hydrogen
= 1. |
|---|
| Oxygen | O | 100·000 | 16·026 |
| Hydrogen | H | 6·2398 | 1·000 |
| 2H | 12·4796 | 2·000 |
| Nitrogen | N | 88·518 | 14·186 |
| 2N | 177·086 | 28·372 |
| Phosphorus | P | 196·155 | 31·436 |
| 2P | 392·310 | 68·872 |
| Chlorine | Cl | 221·325 | 35·470 |
| 2Cl | 442·650 | 70·940 |
| Iodine | I | 768·781 | 123·206 |
| 2I | 1537·562 | 246·412 |
| Carbon | C | 76·437 | 12·250 |
| 2C | 152·875 | 24·500 |
| Boron | B | 135·983 | 21·793 |
| 2B | 271·966 | 43·586 |
| Silicon | Si | 277·478 | 44·469 |
| Selenium | Se | 494·582 | 79·263 |
| Arsenic | As | 470·042 | 75·329 |
| 2As | 940·084 | 150·659 |
| Chromium | Cr | 351·819 | 56·383 |
| 2Cr | 703·638 | 112·766 |
| Molybdenum | Mo | 598·525 | 95·920 |
| Tungstenium | Tu or W | 1183·200 | 189·621 |
| Antimony | Sb | 806·452 | 129·243 |
| 2Sb | 1612·904 | 258·486 |
| Tellurium | Te | 806·452 | 129·243 |
| Tantalum | Ta | 1153·715 | 184·896 |
| 2Ta | 2307·430 | 369·792 |
| Titanium | Ti | 389·092 | 62·356 |
| Gold (aurum) | Au | 1243·013 | 199·207 |
| 2Au | 2486·026 | 398·415 |
| Platina | Pt | 1215·220 | 194·753 |
| Rhodium | R | 750·680 | 120·305 |
| 2R | 1501·360 | 240·610 |
| Palladium | Pd | 714·618 | 114·526 |
| Silver (argentum) | Ag | 1351·607 | 216·611 |
| Mercury (hydrargyrus) | Hg | 1265·822 | 202·863 |
| 2Hg | 2531·645 | 405·725 |
| Copper (cuprum) | Cu | 395·695 | 63·415 |
| 2Cu | 791·390 | 126·829 |
| Uranium | U | 2711·360 | 434·527 |
| 2U | 5422·720 | 869·154 |
| Bismuth | Bi | 1330·376 | 213·208 |
| 2Bi | 2660·752 | 426·416 |
| Tin (stannum) | Sn | 735·294 | 117·839 |
| Lead (plumbum) | Pb | 1294·498 | 207·458 |
| 2Pb | 2588·996 | 414·917 |
| Cadmium | Cd | 696·767 | 111·665 |
| Zinc | Zn | 403·226 | 64·621 |
| Nickel | Ni | 369·675 | 59·245 |
| Cobalt | Co | 368·991 | 59·135 |
| 2Co | 737·982 | 118·270 |
| Iron (ferrum) | Fe | 339·213 | 54·363 |
| 2Fe | 678·426 | 108·725 |
| Manganese | Mn | 355·787 | 57·019 |
| 2Mn | 711·575 | 114·038 |
| Cerium | Ce | 574·718 | 92·105 |
| 2Ce | 1149·436 | 184·210 |
| Zirconium | Zr | 420·238 | 67·348 |
| 2Zr | 840·476 | 134·696 |
| Yttrium | Y | 401·840 | 64·395 |
| Beryllium (glucinum) | Be | 331·479 | 53·123 |
| 2Be | 662·958 | 106·247 |
| Aluminum | Al | 171·167 | 27·431 |
| 2Al | 342·234 | 54·863 |
| Magnesium | Mg | 158·353 | 25·378 |
| Calcium | Ca | 256·019 | 41·030 |
| Strontium | Sr | 547·285 | 87·709 |
| Baryum | Ba | 856·88 | 137·325 |
| Lithium | L | 127·757 | 20·474 |
| Natrium (sodium) | Na | 290·897 | 46·620 |
| 2Na | 581·794 | 93·239 |
| Kalium (potassium) | K | 489·916 | 78·515 |
| Ammonia | 2N 2H3 | 214·474 | 34·372 |
| Cyanogen | 2NC | 329·911 | 52·872 |
| Sulphuretted hydrogen | 2HS | 213·644 | 34·239 |
| Hydrochloric acid | 2HCl | 455·129 | 72·940 |
| Hydrocyanic acid | 2HNC | 342·390 | 54·872 |
| Water | 2. | 112·479 | 18·026 |
| 2H |
| Protoxide of nitrogen | 2. | 277·036 | 44·398 |
| 2N |
| Deutoxide of nitrogen | . | 188·518 | 30·212 |
| N |
| Nitrous acid | 2... | 477·036 | 76·449 |
| 2N |
| Nitric acid | .·.·. | 677·036 | 108·503 |
| 2N |
| Hyposulphurous acid | . | 301·165 | 48·265 |
| S |
| Sulphurous acid | .. | 401·165 | 64·291 |
| S |
| Hyposulphuric acid | .·.·. | 902·330 | 144·609 |
| 2S |
| Sulphuric acid | ... | 501·165 | 80·317 |
| S |
| Phosphoric acid | .·.·. | 892·310 | 143·003 |
| 2P |
| Chloric acid | .·.·. | 942·650 | 151·071 |
| 2Cl |
| Perchloric acid | ::: | 1042·650 | 167·097 |
| 2Cl |
| Iodic acid | .·.·. | 2037·562 | 326·543 |
| 2I |
| Carbonic acid | .. | 276·437 | 44·302 |
| C |
| Oxalic acid | 2... | 452·875 | 72·578 |
| 2C |
| Boracic acid | 2::: | 871·966 | 139·743 |
| 2B |
| Silicic acid | ... | 577·478 | 92·548 |
| Si |
| Selenic acid | .. | 694·582 | 111·315 |
| Se |
| Arsenic acid | .·.·. | 1440·084 | 230·790 |
| 2As |
| Protoxide of chrome | 2... | 1003·638 | 160·840 |
| 2Cr |
| Chromic acid | ... | 651·819 | 104·462 |
| Cr |
| Molybdic acid | ... | 898·525 | 143·999 |
| Mo |
| Tungstic, or wolfram acid | ... | 1483·200 | 237·700 |
| W |
| Oxide of antimony | 2... | 1912·904 | 306·565 |
| 2Sb |
| Antimonious acid | .. | 1006·452 | 161·296 |
| Sb |
| .... | 2012·904 | 322·591 |
| 2Sb |
| Antimonic acid | 2.·.·. | 2112·904 | 338·617 |
| 2Sb |
| Oxide of tellurium | .. | 1006·452 | 161·296 |
| Te |
| Tantalic acid | ... | 2607·430 | 417·871 |
| 2Ta |
| Titanic acid | .. | 589·092 | 94·409 |
| Ti |
| Protoxide of gold | . | 2586·026 | 414·441 |
| 2Au |
| Peroxide of gold | ... | 2786·026 | 446·493 |
| 2Au |
| Oxide of platina | .. | 1415·220 | 226·086 |
| Pt |
| Oxide of rhodium | 2... | 1801·360 | 228·689 |
| 2R |
| Oxide of palladium | . | 814·618 | 130·552 |
| Pd |
| Oxide of silver | . | 1451·607 | 232·637 |
| Ag |
| Protoxide of mercury | . | 2631·645 | 421·752 |
| 2Hg |
| Peroxide of mercury | . | 1365·822 | 218·889 |
| Hg |
| Protoxide of copper | . | 801·390 | 142·856 |
| 2Cu |
| Peroxide of copper | . | 495·695 | 79·441 |
| Cu |
| Protoxide of uranium | . | 2811·360 | 450·553 |
| U |
| Peroxide of uranium | 2... | 5722·720 | 917·132 |
| 2U |
| Oxide of bismuth | 2... | 2960·752 | 474·49 |
| 2Bi |
| Protoxide of tin | . | 835·294 | 133·866 |
| Sn |
| Peroxide of tin | .. | 935·294 | 149·892 |
| Sn |
| Oxide of lead | . | 1394·498 | 223·484 |
| Pb |
| Minium | ... | 2888·996 | 462·995 |
| 2Pb |
| Brown oxide of lead | .. | 1494·498 | 239·511 |
| Pb |
| Oxide of cadmium | . | 796·767 | 127·691 |
| Cd |
| Oxide of zinc | . | 503·226 | 80·649 |
| Zn |
| Oxide of nickel | . | 469·675 | 75·271 |
| Ni |
| Oxide of cobalt | . | 468·991 | 75·161 |
| Co |
| Peroxide of cobalt | ... | 1037·982 | 166·349 |
| 2Co |
| Protoxide of iron | . | 439·213 | 70·389 |
| Fe |
| Peroxide of iron | ... | 978·426 | 156·804 |
| 2Fe |
| Protoxide of manganese | . | 455·787 | 73·045 |
| Mn |
| Oxide of manganese | ... | 1011·575 | 162·117 |
| 2Mn |
| Peroxide of manganese | .. | 555·787 | 89·071 |
| Mn |
| Manganesic acid | .·.·. | 1211·575 | 194·169 |
| 2Mn |
| Protoxide of cerium | . | 674·718 | 108·132 |
| Ce |
| Oxide of cerium | ... | 1449·436 | 232·289 |
| 2Ce |
| Zirconia | ... | 1140·476 | 182·775 |
| 2Zr |
| Yttria | . | 501·840 | 80·425 |
| Y |
| Glucina, or berryllia | ... | 962·958 | 154·325 |
| 2Be |
| Alumina | ... | 642·334 | 109·942 |
| 2Al |
| Magnesia | . | 258·353 | 41·404 |
| Mg |
| Lime | . | 356·019 | 57·056 |
| Ca |
| Strontia | . | 647·285 | 103·735 |
| Sr |
| Baryta | . | 956·880 | 153·351 |
| Ba |
| Lithia | . | 227·757 | 36·501 |
| L |
| Natron, or soda | . | 390·897 | 62·646 |
| Na |
| Peroxide of sodium | ... | 881·794 | 141·318 |
| 2Na |
| Kali, or potassa | . | 589·916 | 94·541 |
| K |
| Peroxide of potassium | ... | 789·916 | 126·593 |
| K |
| Sulphate of potassa | . ... | 1091·081 | 174·859 |
| K S |
| Protosulphate of iron | . ... | 940·378 | 150·706 |
| Fe S |
| Persulphate of iron | ... ... | 2481·906 | 397·754 |
| 2Fe S3 |
| Protochloride of iron | Fe 2Cl | 781·863 | 125·303 |
| Perchloride of iron | 2Fe 2Cl3 | 2006·376 | 321·545 |
| Protochloride of mercury | 2Hg 2Cl | 2974·295 | 476·666 |
| Perchloride of mercury | Hg 2Cl | 1708·472 | 273·803 |
| Ferrocyanide of iron | Fe2NC + 2K2NC | 2308·778 | 370·008 |
| Alum | . ... + 2... ... + 24 2 . | 5936·406 | 951·378 |
| K S + 2Al S3 + 24 2H |
| Felspar | . ... + 2 ... ... | 3542·162 | 567·673 |
| K Si + 2Al Si3 |
FOUNDING of metals, chiefly of Iron. The operations of an iron foundry consist in re-melting the pig-iron of the blast furnaces, and giving it an endless variety of forms, by casting it in moulds of different kinds, prepared in appropriate manners. Coke is the only kind of fuel employed to effect the fusion of the cast iron.
The essential parts of a well-mounted iron foundry, are,
1. Magazines for pig irons of different qualities, which are to be mixed in certain proportions, for producing castings of peculiar qualities; as also for coal, coke, sands, clay, powdered charcoal, and cow-hair for giving tenacity to the loam mouldings.
2. One or more coke ovens.
3. A workshop for preparing the patterns and materials of the moulds. It should contain small edge millstones for grinding and mixing the loam, and another mill for grinding coal and charcoal.
4. A vast area, called properly the foundry, in which the moulds are made and filled with the melted metal. These moulds are in general very heavy, consisting of two parts at least, which must be separated, turned upside down several times, and replaced very exactly upon one another. The casting is generally effected by means of large ladles or pots, in which the melted iron is transported from the cupola, where it is fused. Hence the foundry ought to be provided with cranes, having jibs movable in every direction.