A modern piercing is performed using jewelry and equipment that is either single use and sterile or that has been sterilized in an autoclave sterilization machine.

Meta-aminophenol is prepared by reducing metanitrophenol, or by heating resorcin with ammonium chloride and ammonia to 200° C. Dimethyl-meta-aminophenol is prepared by heating meta-aminophenol with methyl alcohol and hydrochloric acid in an autoclave; by sulphonation of dimethylaniline, the sulphonic acid formed being finally fused with potash; or by nitrating dimethylaniline, in the presence of sulphuric acid at 0° C. In the latter case a mixture of nitro-compounds is obtained which can be separated by the addition of sodium carbonate.

Monomethyl and dimethyl aniline are colourless liquids prepared by heating aniline, aniline hydrochloride and methyl alcohol in an autoclave at 220°.

This picture shows me using the autoclave to destroy the cultures which had grown on the agar plates during incubation.

When the pressure gage reaches zero wait one or two minutes before opening the autoclave.