General view of an apparatus used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory to test catalysts under one atmosphere of pressure.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was…

General view of an autoclave and still at the Fixed Nitrogen Research Laboratory's Urea Plant. Urea is a water-soluble powder form of carbonic acid frequently used as a fertilizer and feed supplement.

The Fixed…

General view of the auxiliary gasoline engine used at the Fixed Nitrogen Research Laboratory's catalyst testing plant. The insignia of the General Motors Company is visible at the base of the engine.

The Fixed Nitrogen…

General view of C.A. Black demonstrating use of an apparatus for filling tubes in order to study ammonia-carbon dioxide-Urea-water systems at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory…

Two views of Mr. C.A. Black with an apparatus used to measure the solubility of methane in hydrocarbons under high pressures at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in…

General view of Mr. C.M. Sullivan (left) and Mr. P.N. Tierney (right) with an iron burner used for the preparation of ammonia catalysts at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located…

General view of a carbon dioxide drier, compressor, liquifier, and liquid storage used at the Fixed Nitrogen Research Laboratory's Urea Plant. Urea is a water-soluble powder form of carbonic acid frequently used as a…

General view of the carbon dioxide regenerator at the Fixed Nitrogen Research Laboratory's Urea Plant. In the production of fertilizer, liquid carbon dioxide and liquid ammonia are commonly combined under high-pressure…

Three views of the carbon monoxide generator and compressor used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The individual visible in the second and third…

Exterior view of a chemical warfare research laboratory under construction at American University near Washington, D.C. American research concerning chemical warfare was initially organized under the Bureau of Mines,…

General view of a colorimeter used to analyze nitrogen dioxide at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. With regards to chemistry, colorimeters are used to…

View of a combination hot plate and shaker used to investigate potash at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. Potash salts are an important component in the…

General view of the compressors used at the Fixed Nitrogen Research Laboratory's catalyst testing plant.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American University in 1919 under the…

General view of a conference room at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American…

Two views of the construction of the phosphoric acid furnace at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. This furnace was used to make phosphoric acid through…

General view of the control board for the catalyst testing system at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.)…

General view of the control panel for compressors at the Fixed Nitrogen Research Laboratory's Urea Plant. In the production of fertilizer, liquid carbon dioxide and liquid ammonia are commonly combined under…

General view of the control panel for the experimental blast furnace at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The individual visible in the photograph is…

General view of crackers, deoxidizers, and scrubbers at the Fixed Nitrogen Research Laboratory's catalyst testing plant. Numbers are visible on the exterior of the various containers.

The Fixed Nitrogen Research…

General view of the Cyanamide Laboratory at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory facilities located in Washington, D.C. Assorted glassware and laboratory apparatus, including a…

Diagram of an apparatus used to determine nitrogen in the presence of hydrogen. Several component parts of the apparatus are labelled, including a circulating device, combustion tube, and topler pump. The diagram itself…

General view of Dr. C.D. Garby demonstrating an apparatus used to study the formation of nitric oxide in flames at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.
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General view of Dr. D.C. Bardwell inspecting the apparatus used for the fixation of nitrogen by alpha rays at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The…

General view of Dr. E. C. White demonstrating use of an apparatus for the automatic analysis and indication of the carbon monoxide content of a gas stream at the U.S. Department of Agriculture's Fixed Nitrogen Research…

Two views of Dr. E.D. Crittenden with an apparatus used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory to test catalysts at 1 to 100 atmospheres of pressure. Key components of the apparatus…