58 
SIR J. B. LAWES AND PROFESSOR J. H. GILBERT ON THE 
objection to our mode of experimenting; but he did so in a way which showed entire 
ignorance or misconception of our method. 
We have already given our reasons for believing that certainly the losses, and 
probably the gains also, shown in M. Deherain’s experiments w^ere too high. We 
nevertheless, quite agree that there would be losses wdiere he found losses, and that 
there would be gains where he found gains. It is to be observed, however, that it was 
under the conditions of arable culture, that is of artificially aerated soil, and with vege¬ 
tation, that M. Deherain found great losses, whilst it is in well aerated soils, also with 
vegetation, that M. Joulie finds such enormous gains. 
It is further to be observed that the large gains shown in M. J oulie’s results were 
obtained chiefly in the growth of buckwheat, and not with plants of the Leguminous 
family which are reputed to be “Nitrogen collectors^' From our own results, taken 
together with known facts as to agricultural production, and the fertility of soils, it 
may be confidently affirmed that such gains as M. Joulie finds within a period of 
about 14 months, do not take place, either with or without vegetation, in ordinary 
soils, in ordinary practice. 
4. The Experiments of B. E. Dietzell. 
At tlie meeting of the Naturforscher-Versctnimlung at Magdeburg in 1884, 
Dr. Dietzell gave the results of experiments, the primary object of which was to 
determine whether plants absorb combined nitrogen from the atmosphere by their 
leaves; but they equally afford evidence on the question whether they assimilate the 
free nitrogen of the air. The plants selected were peas and clover, each of ydiich he 
grew under four conditions as to manuring. A garden soil, containing 0'4] 5 per cent, 
of nitrogen was used, and the experimental pots were made of hard burnt clay. The 
plants were watered with distilled water, and the drainage was returned to the soils. 
The pots and then- contents were exposed to free air, but protected by a linen roof 
The conditions of the different experiments were as follows :—No. 1, without 
manure; No. 2, manured with kainite ; No. 3, with kainite and superphosphate ; 
No. 4, with kainite, superphosphate, and calcium carbonate; No. 5, with kainite, 
superphosphate, and calcium carbonate, but without a plant; and No. G, without 
eitlier manure or plant. 
The nitrogen was determined in the original soil, and in the seed ; also in the soil 
at the conclusion of the experiment, and in the plants grown. The following figures 
show the losses or gains of nitrogen, represented in percentage of the original 
nitrogen in soil and seed :— 
