General view of J.F. Shultz demonstrating an apparatus used to analyze the effect of phosphine upon ammonia catalysts at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington,…

Two views of J.E. Reuter at work in the instrument shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and tools.

The Fixed Nitrogen Research Laboratory…

Two views of J.E. Reuter at work in the instrument shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and tools.

The Fixed Nitrogen Research Laboratory…

General view of a heat converter, interchanger, and condenser used for water-gas hydrogen production at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The term "water…

Two views of the exterior of the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory facility located at American University near Washington, D.C. The Fixed Nitrogen Research Laboratory (F.N.R.L.) was…

General view of the exterior of the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory facility located at American University near Washington, D.C. The Fixed Nitrogen Research Laboratory (F.N.R.L.) was…

General view of the exterior of the Fixed Nitrogen Research Laboratory's Urea Plant, showing assorted apparatus and equipment used to produce Urea, a water-soluble powder form of carbonic acid frequently used as a…

General view of Mr. E.H. Johnston demonstrating an apparatus used for the production of ozone at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen…

General view of Dr. Sebastian Karrer using an apparatus to measure the thermal conductivity of active nitrogen at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The…

General view of Dr. M.F. Fogler demonstrating an apparatus used for the dissociation of nitric acid at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed…

General view of Dr. J.G. Thompson demonstrating use of an ammonia catalyst fusion pot at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research…

General view of Dr. J.G. Thompson (left) and Mr. C.L. Sullivan (right) operating a hydrogen burner during the production of the hydrogen-nitrogen mixture used in the synthesis of ammonia at the U.S. Department of…

Two views of Dr. F.E. Allison studying the fixation of nitrogen by bacteria at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory…

General view of Dr. E.W. Guernsey demonstrating an apparatus used to study the formation of nitric oxide in the explosion of carbon monoxide and oxygen 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…

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…

General view of Dr. D.C. Bardwell using an apparatus to experiment with the chemical effects of radon at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed…

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…

Two views of device used to study positive ions, presumably in the activation of nitrogen gas and hydrogen, at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The…

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 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 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…

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…

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…

Two views of assorted apparatus 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 individuals present…