ABSTRACT
In order to arrive at an adequate understanding of mental processes it is necessary to have some idea of the machinery whereby the mind makes contact with the body. The sense organs act as receivers of sensation, the nerve fibres as transmitters, the central nervous system as a general telephone exchange, and the muscles, glands, and organs as the executants of the impulses of the mind. Muscles are composed of long, spindle-shaped cells which are capable of contraction. Chemical changes are constantly going on in their substance. The blood and lymph which bathe them bring food materials and carry away the waste products of their activity. These food substances, which are highly organised chemical compounds, are stored in the body of the cell. The glands are the chemists of the body and in the crucibles of their minute cells carry out the wonderful processes of living chemistry upon which our vital functions are based.
