An apparatus for obtaining a balance of induction from two coils acting upon a third. The third is placed between the other two and is free to move towards either. A scale is provided to show the extent of its movement. A varying or interrupted current being passed through the two outer coils, the preponderating [...]

The tendency to approach and adhere or cohere, shown by all forms of matter. It includes gravitation, cohesion, adhesion, chemical affinity and other forms, and is opposed by repulsion, and is sometimes overcome by it, although it may be assumed to be always present. See the different kinds of attractions under their titles: Atomic Attraction, [...]

The number expressing the relative weight of the atom of any substance, that of hydrogen being generally taken as unity. This is the universal system, although any other element might be taken as the basis of the system. The whole theory of atomic weights is based on the indivisibility of the atom and on the [...]

The quantivalence or valency of the atoms; the number of combination bonds, or bonds of affinity, possessed by the atoms of any substance. Thus two atoms of hydrogen combine with one atom of oxygen, and three of oxygen with one of sulphur, forming saturated compounds. Therefore, taking hydrogen as of single atomicity or a monad, [...]

The product of the atomic weight of a substance by its specific heat. This product is approximately the same, 6.4; this approximation is so close that it is of use in determining the valency and atomic weights of substances. The atomic weight of a substance therefore represents the approximate number of gram-calories required to raise [...]

The attraction of atoms for each other, in virtue of which they combine into molecules; chemical affinity, q. v., treats principally of this, although molecular attraction also plays a part in it.

The ultimate particle or division of an elementary substance; the smallest part that can exist in combination, and one which cannot exist alone. An elementary substance is composed of molecules just as truly as a compound one, but the atoms in the molecule of an elementary substance are all precisely alike. Hence atoms are the [...]

The electricity of the atmosphere, rarely absent, but often changing in amount and sign. Benjamin Franklin, in a memoir published in 1749, indicated the method of drawing electricity from the clouds by pointed conductors. In June, 1752, he flew a kite and by its moistened cord drew an electric spark from the clouds, confirming his [...]

The atmosphere left in a vessel after exhaustion. The term may be applied to any gas. In an incandescent lamp after flashing the residual atmosphere consists of hydro-carbons.

(a) A term applied to the atmospheric pressure as a practical unit of pressure equal to 15 lbs. to the square inch as generally taken. It is really about 14.7 lbs. per square inch, or 1,033 grams per square centimeter. (b) Air, q. v.