1. The waxes in use for candles consist of paraffin and, in special cases, of beeswax.
2. Stearic acid is the only known hardening agent for paraffin. It raises the bending (softening) point and lowers the melting point. It can be used in any quantity without impairing the burning quality of the candle.
3. No other wax, natural or synthetic, can be substituted for stearic acid as a hardening agent for candle stock. Other waxes generally injure the burning quality of the candle or fail to produce any improvement, being at the same time more expensive than stearic acid.
4. The hydrogenated oils and fats serve as hardening agents for paraffin, especially for scale paraffin wax, and are used chiefly for candles which are consumed in glasses.
5. Synthetic or natural resins can be used in form of coatings only and are used chiefly for decorative candles.
6. No known synthetic hardening agent for candle wax can be satis-factorily substituted for stearic acid, even in such a mixture as 95% paraffin (MP 135°) and 5% stearic acid.