602,781. Uniting metal to piezo-electric crystals. GOLDER, E. V., and FLETCHER, D. B. Nov. 30, 1945, No. 32489. [Class 36] [Also in Group XL (c)] A method of attaching a contact wire to a piezo-electric crystal comprises embedding part of the wire in a blob of silvering paste on the crystal and baking the assembly to reduce the paste to a hard conducting mass. Specification 566,718, [Group II], is referred to.