A variety of substitutes have been developed, notably trichloromethyl chloroformate (diphosgene), a liquid at room temperature, and bis(trichloromethyl) carbonate (triphosgene), a crystalline substance.

They called it the crystalline substance transfer theory in dimensional physics.

The growth rate of the resultant crystalline substance will depend on how fast this latent heat can be conducted away.

It contains about 8% terpenes; about 65% of a resin which contains sulfur; about 20% gum; and a very small quantity of the colorless crystalline substance umbelliferone.

Two crystalline substances are deposited on either side of a microscope slide and are sequentially melted and resolidified.