When the picture is sufficiently impressed, he etches it into the plate by means of bichloride of platinum. 弗雷德里克·科利尔·贝克维尔.伟大的事实.
The record plate is then subjected to a particularly constituted acid bath, which, entering the groove or grooves formed by the stylus, cuts or etches the same into the plate. 威廉·亨利·杜利特.世纪发明.