The decomposition rate of 30% hydrogen peroxide was measured when hydrogen peroxide was mixed with 36% hydrochloric acid and anaesthesia either in 5:5:1 solution and in a solution of 20% sodium hydroxide at temperatures of 16 degrees to 20 degrees C and at 45 degrees C, respectively. The effect of ferris chloride on the decomposition of hydrogen peroxide was also observed. The decomposition of 30% hydrogen peroxide in sodium hydroxide solution was faster than that in the mixture of hydrochloric acid and ether at low temperature (16 degrees to 20 degrees C). The decomposition of hydrogen peroxide was accelerated by heat. The experiment implies that the bleaching effect of hydrogen peroxide can be achieved without heat by use of a sodium hydroxide solution. Further study on the rationale of the compound of the McInnes solution (hydrogen peroxide, hydrochloric acid, and anaesthesia ether mixed at a ratio of 5:5:1) is needed.