AN EARLY EXPERIMENT OF JAMES WOODHOUSE UPON THE SYNTHETIC PRODUCTION OF AMMONIA* C. A. BROWNE BUREAUoa CEIEMISTRY AND SOILS, U. S. DEPARTMENT OP AGRICULTURE, WASHINGTON, D. C.
On July 1, 1930, the writer spent a very interesting half day in examining the autograph letters of prominent chemists in the famous Darmstadter Collection of the Preussische Staatsbihliothek in Berlin. This collection of letters, papers, manuscripts, and other documents is a perfect mine of biographic and historical information invaluable to the student of the history of chemistry. Here are found original communications in the handwriting of Thurneyser, Boyle, Becker, Lemery, Stahl, Black, Priestley, Scheele, Lavoisier, Fourcroy, Gay-Lussac, and hundreds of other noted chemists. These documents extend over a period of three centuries, and their complete perusal would require many days. One letter of this collection especially attracted the writer's attention for it was indexed "Lettre de M. Woodhouse, Profes: de Chimie en 1'Universite de (Pennsylvania) a MM les Redacteurs des Annales de Chimie." The communication was in French and read as follows: Philadelphia, September 29, 1809. Messieurs: M'etant propose d'analyser la suie j'ai expose, dans un creuset couvert, pendant deux heures, la chaleur d'un fourneau rkverberatoire, une livre de cette substance melee deux onces de potasse. Le melange refroidi et place sur uge assiette, je versai dessus une petite quantite d'eau froide et le vis s enflammer sur le champ. Presumant qu'il se formoit de l'eau, j'aspirai le gas qni se degageait, et que je supposais devoir etre de l'hydrogene, mais je fus hien surpris de trouver que c'etait du gas alkalin. L'experience repetee avec du charbon donna le meme resultat. L'azote est nn des elements de I'ammoniac, qui ne coutient ni la potasse, ni l'eau ni le charbon; d'ou vient donc que le melange de ces substances a pu produire du gas ammoniac? , Est ce une des parties constituantes de la potasse? ou bien cette derniere substance est elle un triple compose d'oxygene, d'azote, et de ce metal que le Professeur Davy vient de decouvrir? Quelquefois l'hydrogene qui s'eleve se combine avec l'azote contenu dans l'atmosphere et forme du gas ammoniac mais ce n'est pas la le cas dans mon experience. Car si Son eteint au moyen d'eau le feu produit par le melange de potasse et de charbon et qu'immediatement aprits on le couvre d'une cloche renfermant de l'air atmospherique, la portion de gas oxigitnit sera ahsorbee et l'azote demeura lihre. sign6 JAMES WOODHOUSE, Professeur de Chimie dans l'Universit6 de Pennsylvania *Read before the Division of History of Chemistry of the American Chemical Society at New Orleans, March 30, 1932. 1744
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A photographic copy of the letter was procured from the librarian of the Staatsbibliothek through the kind offices of Mr. Loyd V. Steere, Agricultural Attache of the American Embassy in Berlin. A comparison of the handwriting with that of an authentic letter of Woodhouse in the Edgar F. Smith Memorial Collection a t the University of Pennsylvania, made by the curator, Miss Eva Armstrong, indicates that the French letter in the Darmstadter collection was not written by Woodhouse. This fact and the word sign4 prefixed to Woodhouse's name a t the end of the letter would seem to show that the letter is a French translation by an unknown person of an original letter by Woddhouse. Woodhouse died on June 4, 1809, and as this is nearly four months earlier than the date of the French letter in the Darmstadter collection we are obliged to conclude either that a mistake had been made in the dating of the letter by the translator or that the translation was not made until after Woodhouse's death. A search in the volumes of the Annales de Chimie for 1808 to 1812 in the library of the U. S. Department of Agriculture shows no reference to the communication of Woodhouse. The December issue of Nicholson's Journal of Natural Philosophy, Chemistry and the Arts for 1808 (Vol. XXI, p. 290) published, however, the original English letter of Woodhouse, of which the French letter in the Darmsadter collection is almost an exact translation. Woodhouse's original letter, as published in Nicholson's, is reproduced herewith. Account of an Experiment in which Potash calcined with Charcoal took Fire on the Addition of Water, and Ammoniacal Gas was produced. In a Letter from James Wo8dhouse, University of Philadelphia, &c. Philadelphia, Sept. 15, 1808. To the Editor of the Philosophical Journal. SIR: Having been engaged in the analysis of soot, I exposed half a pound of this substance in powder, mixed with two ounces of pearlash, in a covered crucible, t o the intense heat of an air furnace, for two hours. When the mixture became cold, it was emptied upon a plate, and a small quantity of cold water poured upon it, when it immediately caught fire. Expecting there was a decomposition of water, I placed my nose over the mixture, in order to smell the hidrogen gas, which I supposed would be thrown off, but was astonished to find a disengagement of ammoniacal gas. The ex~erimentwas reoeated with common charcoal. with exactlv the samh result. Azote is one of the com~onent arts of ammonia. Now. as this base is not contained in ekher p&sh, water, or charcoal,. whence did i t arise, to form the ammoniacal gas? Is i t one of the component parts of potash? or is this substance a triple compound, formed of oxigen, azote, and the peculiar metal, which Professor Davy has discovered?
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JOURNAL OF CHEMICAL EDUCATION
OCTOBER, 1932
Nascent hidrogen sometimes combines with the azotic portion of atmospheric air, and forms ammoniacal gas; but this is not the case in my experiment, for, if the fire of the mixture of charcoal and potash be extinguished by water, and it is then immediately placed under a hell glass containing atmospheric air, the oxigenous part will be absorbed, and the azotic air, will be left behind. No carbonic acid will be formed. I am, Sir, Your humble servant, JAMES WOODHOUSE
It will be noted that the date of Woodhouse's English letter is Sept. 15, 1808, and i t seems reasonable to believe that the French letter, which would naturally have been prepared a t about the same time, should have been dated September 29, 1808, instead of September 29, 1809. In comparing the French translation with the English original several slight differences are noted. The quantity of soot specified in the French letter is given as one pound and in the English as half a pound. The words "peculiar," as applied to the metal which navy discovered, and "nascent," as applied to hydrogen, and the final sentence "No carbonic acid will he formed" of the English letter are omitted in the French translation. These variations and the several misspellings of French words (such as reverbatare instead of reverberatoire) indicate that the translation was hastily made and probably by a person who was not a chemist. A reference to this experiment, but without indication of the source of information, is contained on page 189 of Pmith's "James Woodhouse. A Pioneer in Chemistry 177CF1809," from which the following passage is quoted. It is remarkable that in the same year (1808) James Woodhouse observed, on exposing a half pound of soot in powder, mixed with two pounds of pearlash, in a covered crucible, to the intense heat of an iron-furnace, for two hours, that he got a mass which, when cold, was emptied upon a plate and when it was covered with a small quantity of cold water, "immediately caught fire." In the course of his remarks, relative to the behavior of the mass, he asked, "could i t be due to the peculiar metal, which Professor Davy has discovered'" Again he got the metal by employing potash. Here, then, in the New World was a student liberating potassium, by an entirely novel method, for it is certain that Woodhouse was unacquainted with the discoveries of Gay-Lnssac and Thenard, and that of Curaudau. Their publications could not have reached him a t the time he reported his experiences. Nowhere in chemical literature is credit given Woodhouse for this discovexy. Thomas Cooper who came out to America with Priestley, living with him for awhile, on one occasion wrote his sonin-law, Dr. Manners, of Philadelphia, that he knew of Woodhouse's isolation of potassium. It may be argued that Woodhouse did not realize the significance of his experiment, and did not recognize his
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potassium as such. If this was true a t first, he did later certainly comprehend the problem in all its phases, and therefore deserves honor equally with Gay-Lussac, and Thenard, as well as with Curaudau. The description of Woodhouse's experiment as given by Professor Smith differs in certain respects from that given by Woodhouse in his letter of Sept. 15, 1808, in Nicholson's Journal. The amount of pearlash is given as two pounds instead of two ounces and an iron furnace is specified instead of an air furnace. I t will also be noted that Woodhouse's query about "the peculiar metal which Professor Davy has discovered as given in his letter relates to a conjecture about the component parts of potash and not to the possibility of his having isolated potassium which is not hinted a t in his discussion. Professor Smith no doubt had possession of other communications by Woodhouse relating to his experiment tlian the one contained in Nicholson's Journal. In addition to these questions of bibliographic significance the letter of Woodhouse has an additional interest to the chemist from the fact that it describes an early experiment upon the fixation of atmospheric nitrogen and the synthetic production of ammonia. The fact that the fused mixture of pearlash (commercial potassium carbonate) and charcoal caught fire upon the addition of water indicates that metallic potassium was probably formed under the conditions of Woodhouse's experiment* type of reaction which has formed the basis of many processes for the production of this metal. As to the production of ammonia in the experiment, Woodhouse rejects the supposition that it could have been f o m d by the combination of nascent hydrogen (produced, as he may possibly have supposed, by the action of water upon metallic potassium) and atmospheric nitrogen, although it is doubtful if the method which he employed to demonstrate this was sufficiently accurate to permit his drawing such a conclusion. Because of these and other uncertainties it appeared to the writer that a repetition of Woodhouse's experiment under more carefully controlled conditions would throw some light upon the mechanism of the chemical processes involved. This repetition has been kindly performed by Katharine S. Love and P. H. Emmett of the Fixed Nitrogen Laboratory of the U. S. Bureau of Chemistry and Soils. The results of their investigation, as given in the following paper, will be of interest not only to students of the history of chemistry in America but also to those who are occupied with the problems of nitrogen fixation.
