work that is to be electro-plated and all work to which a vitreous enamel is to be applied, such as granite ware, etc. Why more structural steel is not cleaned in this way we do not know, but it is well to remember that pickling with hot dilute sulphuric acid or with hot muriatic acid should be avoided, unless one is well prepared to neutralize thoroughly and remove all traces of the acid from the metal immediately after it is taken from its bath.