In this calculation the nitrogen of the urine, which by decomposition is converted into carbonate of ammonia, has not been included.

After the greater portion of the ammonium oxalate has been converted into carbonate, the coloration and necessarily the formation of manganese peroxide begins.

Sulphate of lead is soluble in solutions of ammonium or sodium acetate; or it may be converted into carbonate by boiling with carbonate of soda.