Reaction
in chemistry, the chemical change or effect produced by bringing at least two elements or compounds together whereby one or more new bodies are formed, which may consist either of READ a gas, liquid, or solid, or a mixture of these; as when sulphuric acid is added to chalk, the products of the reaction are sulphate of lime, water, and carbonic acid gas.
In pathology, action of one kind in antagonism with action of another; action immediately following on action of a directly contrary character; or a state succeeding to a directly contrary one, as the exhaustion consequent on a paroxysm of fever.
In physics, the action of one body on another one acting on it in the opposite direction. Reaction period, in physiology, the time that elapses between the application of a stimulus to the nerves, and the contraction of the muscles, following it in consequence. Roughly speaking, it is for feeling one-seventh, for hearing one-sixth, and for sight onefifth of a second.