Blood is to the human body what soil is to the plant. It is common knowledge that poor, exhausted soil will produce only weak, sickly plants. In the same way, poor blood, lacking in essential constituents, will pro-duce weak, sickly bodies, prone to disease. By enriching the soil, the ill-conditioned plant can be made to recover and flourish. The recovery of the ailing human body can best be achieved by a similar process -- by restoring to the blood the constituents in which it is lacking. This is Biochemistry -- The Chemistry of Living Tissue.