composition of the sublimable substance examples of surfactants which can be used include anionic surfactants and nonionic surfactants suitable examples of anionic surfactants include carboxylic acid salts such as sodium stearate sulfuric acid ester salts such as sodium lauryl alcohol sulfate sulfonic acid salts such as sodium dodecylbenzene sulfonate and phosphoric acid salts such as higher alcohol phosphoric acid ester salt they can be used alone or in combination with each other suitable examples of nonionic surfactants include polyhydric alcohol esters such as stearic acid monoglyceride and sorbitan stearate and polyethylene glycol type of surfactants such as nonylphenyl polyethylene glycol ether and stearic acid polyethylene glycol ester the amount of the surfactant added is usually about 0 1 to 40 parts by weight and preferably about 0 5 to 20 parts by weight per 100 parts by weight of the sublimable substance the amount of the sublimable substance added is usually about 0 1 to 100 parts by weight and preferably about 0 2 to 30 parts by weight per 100 parts by weight of water for the dispersion composition of the sublimable substance for use in the present invention when the grain size of the sublimable substance is about 1 micron or less the dispersion is stable over a long period of time where the grain size is relatively large a stabilizer may be added if necessary examples of stabilizers which can be used include hydrophilic polymeric compounds such as cmc pva methyl cellulose starch casein sodium alginate and proteins water soluble compounds such as methanol and ethylene glycol and inorganic gelatinizers such as bentonite and fine powder of silicic acid these stabilizers can be used alone or in combination with each other in the dispersion composition of.