In the gold extraction process, finely crushed ores are leached in vats with a very diluted solution of Potassuim Cyanide (KCN), containing 0.05 to 0.3 percent KCN (or its equivalent, Sodium Cyanide, NaCN) which is allowed to remain for twelve to twenty-four hours to dissolve the gold.

Cyanide Leaching Tank (Gold Extraction)

In the gold extraction process, finely crushed ores are leached in vats with a very diluted solution…

"If air is passed through a strongly heated tube contaning reduced copper or fine-meshed copper gauze, nearly pure nitrogen results." -Brownlee 1907

Preparing Nitrogen

"If air is passed through a strongly heated tube contaning reduced copper or fine-meshed copper gauze,…

"The bottle (a) serves as an aspirator to draw airthrough the apparatus and also to collect the residual nitrogen. the oxygen is removed by combining it with copper (gauze) in the hard glass tube (c), which is heated by the combustion furnace (b)...air has to pass through the bottles (ee) containing a concentrated solution of potassium hydroxide to take out the carbon dioxide, and through the bottles (dd) containing concentrated sulphuric acid to remove the water vapor or moisture. The nitrogen [is] collected in a." -Brownlee 1907

Nitrogen Preparation

"The bottle (a) serves as an aspirator to draw airthrough the apparatus and also to collect the residual…

An apparatus used to produce and capture nitrous oxide. A flask containing ammonium nitrate is heated, which will produce water and nitrous oxide. The water drips into the bottle provided and the nitrous oxide is collected in the inverted bottle.

Nitrous Oxide Preparation

An apparatus used to produce and capture nitrous oxide. A flask containing ammonium nitrate is heated,…

Nodules on the root system of a bean plant where nitrogen-fixing bacteria live.

Nodules, root

Nodules on the root system of a bean plant where nitrogen-fixing bacteria live.

Nodules on the root system of a hairy vetch.

Nodules, root

Nodules on the root system of a hairy vetch.

A wheat plant grown in a pot, stunted as a result of nitrogen deficiency in the soil.

Wheat, potted and stunted

A wheat plant grown in a pot, stunted as a result of nitrogen deficiency in the soil.