MURRAY1 has predicted that crystalline cuprous chloride may be of use as a modulator material in lasers. Crystals of this material are generally grown from the melt2, but the method has certain disadvantages. First, the presence of a phase transition2 15° C below the melting point (422° C) produces strains in the resulting crystals. This is further intensified by temperature gradients produced in the crystal during cooling from the melting point to room temperature. Contamination from container materials is another hazard. We have endeavoured to eliminate these undesirable influences by growing cuprous chloride at room temperature with a variation of the gel growth technique.