86 
SIR J. B. LA WES AND PROFESSOR J. H. GILBERT ON THE 
However this may be, considering only the numerical results which have been 
obtained, he is forced to believe that the soil of Liebfrauenberg has fixed nitrogen ; 
nitric acid and ammonia being at the same time developed. The experiment on 
fallow in confined air seems to indicate that the vegetation has but little to do with 
the result. 
Having given the details of his experiments, he submits them to the criticism of 
others, thus enabling them to judge whether the intervention of the nitrogen of the 
air in the production of nitrates is really established. In his opmion, if there is not 
absolute proof, there is certainly strong presumption, in favour of the reality of the 
phenomenon. 
These very remarkable results seem to have instigated new experiments to test the 
validity of the obvious conclusion from them. In the discussion of the previous 
experiments Boussingault had constantly compared the results obtained in a 
vegetable soil with those in a nitre bed. In reference to these new experiments 
he says that in the nitrification of vegetable earth, and in the materials of an artificial 
nitre bed, everything leads to the conclusion that the nitric acid is developed especially 
at the expense of organic substances. But it does not necessarily follow that the 
gaseous nitrogen of the atmosphere cannot contribute, within certain limits, to the 
production of nitrates. It is to ascertain whether this co-operation takes place that 
the new experiments were undertaken. 
In the next year, I860,* Boussingault placed a mixture of 100 grams of very rich 
vegetable soil, and 300 grams of quartz sand, in a large balloon, such as he used in 
the previous vegetation experiments, moistened the mass, and then closed it perfectly 
by means of a caoutchouc cap. A second experiment was also arranged, in which the 
conditions were precisely similar, excepting that 5 grams of cellulose were added to 
the mixture. The materials could not be stirred, and it was decided to leave them in 
contact with confined air for a considerable time. The two vessels were, in fact, left 
for 11 years, when, in 1871, they were opened, and the contents examined. 
The result was that in both cases there was a very considerable amount of nitrifica¬ 
tion, representing in Experiment 1 rather more, but in Experiment 2 with the cellulose 
less, than one-third of the original nitrogen of the soil. The actual loss of carbon was 
more than 4 times as great in Experiment 2 with the cellulose, as in Experiment 1 
without it; amounting in Exj^erimerit 1 to about 16 per cent., and in Experiment 2 to 
about 43 per cent, of the original quantity. 
Lastly, as to the nitrogen :—In Experiment 1, without cellulose, there was out of 
0'4722 gram total nitrogen in the original soil, aloss of 0‘0212 gram, corresponding to 
4*5 per cent, of the original amount; and in Experiment 2, with the cellulose, there 
was, upon the same original amount of nitrogen a loss of 0'0081 gram, corresponding 
to 171 per cent, of the original. 
* ‘ Compt. Rend.,’ vol. 76, 1873, p. 22. 
