The methods used in the assay for iron are volumetric, and are all based on the property possessed by certain reagents of oxidizing iron from the ferrous to the ferric state.
The method is sometimes employed in the assay of gold.
Helena is delightfully situated with Mt Helena as a background in the hollow of the Prickly Pear valley, a rich agricultural region surrounded by rolling hills and lofty mountains, and contains many fine buildings, including the state capitol, county court house, the Montana club house, high school, the cathedral of St Helena, a federal building, and the United States assay office.
A third addition becomes necessary to remove the rest of the silver, when the lead will assay only o I oz.
The fire assay for copper ores was abandoned years ago and the electrolytic method took its place; this in turn is now largely replaced by volumetric methods.
There are several public assay offices in Italy for silk; the first in the world was established in Turin in 1750.
Ores containing much arsenic or sulphur are generally roasted at a low heat and the assay is made on the roasted material.
The principal officers of the Mint were the master, who manufactured the coin under a contract, the warden or paymaster who acted on behalf of the Crown, the assay master (also a king's officer) who was responsible for the fineness of the coin, the cuneator or superintendent of the engravers of the dies, and the moneyer.
The principal buildings are the state capitol, the United States assay office, a Carnegie library, a natatorium, and the Federal building, containing the post office, the United States circuit and district court rooms, and a U.S. land office.
There is a United States assay office, established as a branch mint in 1837, during the days of North Carolina's great importance as a gold producing state, and closed from 1861 to 1869.