From 1858 to 1861 methylated spirit was duty-free when it was required for manufacturing processes, and the methylation or "denaturizing" was carried out in accordance with a prescribed process.
It is apparently a tropidine monocarboxylic acid, for on exhaustive methylation it yields cycloheptatriene-I.
The potassium salt of the iso-diazo hydroxide yields on methylation a nitrogen ether, R N(CH 3) NO, whilst the silver salt yields an oxygen ether, R N: N OCH 3.
The same oxygen ether is formed by the methylation of the silver salt of the normal diazo hydroxide; this points to the conclusion that the isomeric hydroxides, corresponding with the silver derivatives, have the same structural formulae, namely, R N: N OH.
They behave, however, as tautomeric substances, since their alkali salts on methylation give nitrogen ethers, whilst their silver salts yield oxygen ethers: potassium salt - R N(CH 3).NO 2 nitramine.