If the mixture does not show some cloudiness, it is a strong indication that no lemon oil is present.
Stir until it gets cool enough to thicken, when perfume may be stirred in; geranium, bergamot or lemon oil may be used.
Oil of citronella and oil of lemon grass are sometimes substituted for lemon oil.
Methyl alcohol is sometimes used in place of the more expensive spirit alcohol as a solvent for the lemon oil.
The important ingredients of lemon extract are lemon oil and citral, its aromatic constituent.
The presence of lemon oil may be detected by adding a large excess of water to a small amount of the extract in a test tube.
This is present in the oil of lemon grass, which is sometimes used as a substitute for lemon oil.