The Relative Toxicity of l- and dl-Serine in Rats.

A comparison has been made of the relative toxicity of l- and dl-serine in rats. Under the same experimental conditions, the administration of the natural l isomer was not accompanied by the clinical and pathological alterations and by the chemical changes in the urine, characteristically found in animals receiving the racemie mixture. It appears, therefore, that the unnatural d-isomer is chiefly responsible for the injurious action of dl-serine.