A Non-Parametric Equivalent of Williams' Test for Contrasting Increasing Dose Levels of a Treatment

The toxicity of substances such as drugs, food additives, artificial foods aild pesticides ate usually assessed at some stage by animal experiments. Increasing doses of the substaLnce are given to groups of animals; a group of control animals receiving a zero dose are also included in the experiment. The experimenter wishes to know if there is evidence of toxicity, Lind if so,