This section is from the American Hand Book of the Daguerreotype, by Samuel D. Humphrey. Published S. D. Humphrey, 37 Lispenard Street 1858.
To one quart of muriatic acid add as much oxide of iron (common iron rust) as it will dissolve in two days. This may be done by putting in the oxide in excess. It should be frequently shook, and when wanted for bottling it should be allowed to stand in order to settle. When this is done the solution may be poured off, and reduced by adding to it an equal quantity of water; then it is ready for use. This constitutes a gilding dissolvent now in our market.