ATOMS, OR ATOMIC WEIGHTS, are the original quantities in which bodies either simple or compound combine with each other, referred to a common body taken as unity. Oxygen is taken as the stand ard by some, and hydrogen by others. The atomic weight of a substance is its lowest combining figure : thus if oxygen unites with bodies in several proportions, the lowest of which is 8, then 8 is said to be the atomic weight of oxygen ; it is better termed its equivalent, or its com bining proportion. A knowledge of chemical equivalents, or atomic weights, is of great use to the manufacturer, as it informs him in many cases of the proper quantity of one substance to be mixed with another, and thus saves him from waste or loss. The subjoined is a list of the equivalents of the elementary bodies from which the atomic weights of many of the compounds may be calculated. Those substances which have no figures attached, have not had the equivalents correctly determined: Hydrogen, I Oxygen,. 8
Carbon, 6 Boron, 11 Phosphorus, 32 Sulphur 16 Selenium, 40 Iodine, 126 Bromine, 78 Chlorine, 35 Fluorine, 19 Nitrogen, 14 Potassium, 40 Sodium 24 Lithium, 7 Barium, 69 Strontium 44 Calcium, 20 Magnesium 12 Lanthanum, 44 Cerium, 46 Didymium, Erbium, Terbium, Yttrium, 32 Glucinuni, 5 Aluinimmi, 14 Thorium, 60 Zirconium, 23 Silicium 15 Titanium, 24 Tantalium, 185 Niobium, Pelopium Tungsten 101 Molybdenum, 48 Vanadium, 68 Chromium, 28 Uranium, 60 Manganese, 28 Arsenic, 75 Antimony, 129 Tellurium, 64 Bismuth, 213 Zinc, 32 Cadmium, 56 Tin, 59 Lead, 104 Iron, 28 Cobalt, 30 Nickel, 28 Copper 32 Mercury, 100 Silver, 108 Gold, 200 Platinum, 911 Palladium, 54 Rhodium, 52 Iridium, Osmium, 100 Ruthenium,