(See [Book of the Human Body].)
What are the common names of familiar chemical substances?
Common Names of Chemicals
| Common Names | Chemical Names and Formulæ |
|---|---|
| Alum | Sulphate of Aluminum and Potassium |
| Aqua Fortis | Nitric Acid, HNO3 |
| Aqua Regia | Nitro-Hydrochloric Acid |
| Calomel | Mercurous Chloride, Hg2Cl2 |
| Carbolic Acid | Phenol, C6H5OH |
| Caustic Potash | Potassium Hydrate, KOH |
| Caustic Soda | Sodium Hydrate, NaOH |
| Chalk | Calcium Carbonate, CaCO3 |
| Copperas | Sulphate of Iron |
| Corrosive Sublimate | Mercuric Chloride, HgCl2 |
| Cream of Tartar | Potassium Bitartrate |
| Epsom Salts | Magnesium Sulphate |
| Ether | Diethyl Oxide, (C2H5)2O |
| Fire Damp | Light Carburetted Hydrogen |
| Galena | Lead Sulphide, PbS |
| Glauber’s Salt | Sodium Sulphate |
| Glucose of Grape Sugar | Dextrose, C6H12O6 |
| Goulard Water | Basic Acetate of Lead |
| Iron Pyrites | Iron Di-Sulphide, FeS2 |
| Jewelers’ Putty | Oxide of Tin |
| Laughing Gas | Nitrous Oxide, N2O |
| Lime | Calcium Oxide, CaO |
| Lunar Caustic | Silver Nitrate, AgNO3 |
| Mosaic Gold | Bi-Sulphide of Tin |
| Muriatic Acid | Hydrochloric Acid, HCl |
| Olefiant Gas | Ethylene, C2H4 |
| Plaster of Paris | Calcium Sulphate |
| Quartz | Silicon Dioxide, SiO2 |
| Realgar | Arsenic Di-Sulphide, As2S2 |
| Red Lead | Oxide of Lead, Pb3O4 |
| Rochelle Salt | Sodium Potassium Tartrate |
| Salammoniac | Ammonium Chloride |
| Salt, Common | Sodium Chloride, NaCl |
| Salt of Tartar | Potassium Carbonate |
| Saltpeter | Potassium Nitrate, KNO3 |
| Salts of Lemon | Oxalic Acid |
| Slaked Lime | Calcium Hydrate |
| Soda | Sodium Carbonate |
| Spelter | Zinc |
| Spirits of Hartshorn | Amm. Hydroxide, NH4OH |
| Spirits of Salt | Hydrochloric Acid, HCl |
| Sugar of Lead | Lead Acetate |
| Tartar Emetic | Potass. Antimony Tartrate |
| Verdigris | Basic Copper Acetate |
| Vermilion | Sulphide of Mercury |
| Vinegar | Dilute Acetic Acid |
| Vitriol, Blue | Copper Sulphate |
| Vitriol, Green | Ferrous Sulphate |
| Vitriol, Oil of | Sulphuric Acid, H2SO4 |
| Vitriol, White | Zinc Sulphate |
| Volatile Alkali | Ammonia |
What is meant by radio-activity and radio-active substances?
Radio-activity is the phenomenon associated with substances which spontaneously emit rays of unique penetrating power through the escape of electrons and their striking against other substances. Chief of the radio-active substances are radium, polonium, actinium, thorium, etc.
What is the history of these substances?
Henri Becquerel in 1896 first observed this in the case of potassium uranyl sulphate, the rays from which he found affected a photographic plate through black paper, thin plates of metal, etc.; the property was further traced in other uranium salts and in uranium itself. These rays are known as Becquerel rays, and have the further power to render air a conductor of electricity, and thus to discharge any electrified substance placed near them.
A charged electroscope forms a test of radioactivity, and the rate at which the leaves fall measures the degree. Different uranium salts have different degrees of radio-activity; some varieties of pitchblende, as also chalcolite, show the property in excess of uranium contained.
Madame Curie, by using the activity test for every precipitate obtained from pitchblende, succeeded in discovering the elements polonium and radium in 1898. The next year Debierne discovered actinium, another radio-active element in the same substance. Meanwhile Schmidt and Madame Curie independently found that the same properties were associated with thorium, its compounds and the minerals containing it. In 1903 Ramsay and Soddy discovered that radium continuously produces helium, the lightest of the inactive gases discovered by Ramsay in 1896.