Seidlitz powders are usually put up in two papers. The larger blue paper cootain3 tartarized soda (also called Ro-chelle salt) two drachms, and carbonate of soda two scruples; in practice it will be found more convenient to mix the two materials in larger quantity by passing them twice through a sieve, and then divide the mixture either by weight or measure, than to make each powder separately.

Directions for use. - Dissolve the contents of blue paper in half a tumbler of cold water, stir in the other powder, and drink during effervescence.