Abstract: A method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600.degree. C.

Abstract: High purity silica powder formed from a sol-gel process is made from a quantity of an industrial grade hydrolizable silicon organometallic substance mixed with a quantity of an industrial grade organic solvent miscible in said organometallic substance and with a quantity of an acidified water having a pH less than 2 to form a solution. The solution is heated, then dried to form a gel, milled, and calcined to form the pure silica powder and the pure powder used to form encapsulated micro-miniature circuits.