Summary 1. Rats and mice were intubated with single doses of a new miticidal compound, di-(p-chlorophenyl) methylcarbinol (DMC). The effect of graded doses on ultimate survival is discussed and the ability of large doses to produce signs suggestive of nervous impairment is described. 2. A powdered diet containing 0.1% DMC was well tolerated by growing rats during a ten week period. 3. The results compare favorably with those obtained in a similar limited study of DDT in another laboratory.