Abstract
The author has examined the effects of central stimulants and depressants on the concentration of calcium in the various parts of the central nervous system of guinea-pigs and has found that Ca is conspicuously concentrated in the mesand the diencephalon at the time of excitation or sleep induced by the medicaments. This high accumulation of Ca is proportional to the degree of excitation or sleep and returns gradually to normalcy along with the recession of such states.
