As far back as 1771 he affirmed that certain plants had the power of absorbing free nitrogen; and this opinion he supported by the results of certain experiments he had made on the subject. Eight years later,--viz., in 1779--Ingenhousz further supported this conclusion, and stated that all plants could absorb, within the space of a few hours, noticeable quantities of nitrogen gas. The first to oppose this theory was de Saussure, who, in 1804, carried out experiments which showed that plants were unable to utilise free nitrogen. Subsequent experiments, carried out by Woodhouse and Senebier, supported de Saussure's conclusions. Mention has already been made of Boussingault's elaborate researches on the subject.[25] His first experiments were carried out in 1838. He concluded that plants did not absorb free nitrogen. Georges Ville was the first to reassert the older theory, put forward by Priestley and Ingenhousz. His opinion was founded on experiments he had carried out during the years 1849-52. The subject created so much interest at the time, that a committee of the French Academy--consisting of Dumas, Regnault, Peligot, Chevreul, and Decaisne--were appointed to investigate Ville's experiments. The result of the investigation of the Commission was to confirm Ville's experiments. It is a significant fact, however, that the plant experimented with by the Commission was _cress--a non-leguminous plant_. It has been commonly assumed that the results of recent experiments have confirmed Ville's experiments. It is only proper to point out that this is not a necessary inference. The assimilation of free nitrogen by the _leguminosae_, so far as modern research has revealed, only takes place under the influence of micro-organic life. Ville's experiments, however, were supposed to be conducted under _sterilised_ conditions. In the meantime the results of Boussingault's second series of experiments, carried out between the years 1851 and 1855, were published, and confirmed his earlier experiments. The results of a large number of experiments subsequently carried out were in support of Boussingault's conclusions. Among them may be mentioned Mene, Harting, Gunning, Lawes, Gilbert and Pugh, Roy, Petzholdt, and Bretschneider.