Its methyl derivatives yield the corresponding carboxylic acids when oxidized by potassium permanganate.
There are various haloid derivatives of sulphurous acid.
Paraffins are found in all crude oils, and olefines in varying proportions in the majority, while acetylene has been found in Baku oil; members of the benzene group and its derivatives, notably benzene and toluene, occur in all petroleums. Naphthenes are the chief components of some oils, as already indicated, and occur in varying quantities in many others.
The amino derivatives are stable bases which readily yield substitution derivatives when acted upon by the halogen elements.
Hydriodic acid and phosphorus at high temperature give a dihydro-compound, whilst sodium and alcohol give hexaand octo-hydro derivatives.