QUESTION OF THE SOURCES OF THE NITROGEN OF VEGETATION. 
55 
In the results given in the Table no account is taken of the nitrogen in the seed 
sown, which is estimated at not more than 2 to 3 millig. in the buckwheat, and the 
same in the rye-grass and trefoil, or in all not more than from 4 to 6 millig., which 
M. JoULiE thinks was largely compensated by leaves of the buckwheat carried away 
by the wind. He considers that the results are as exact as possible in experiments 
of the kind. He concludes that, as in M. Berthelot’s experiments, the results 
establish the reality of the fixation of free nitrogen in the presence of clay; and 
further, that the fixation takes place to a greater extent in the presence of vegetation, 
when the conditions are favourable for the development of the plants. 
In the second series of experiments sand instead of soil was used. The percentage 
of nitrogen in it was only 0’0069, so that the actual amount of combined nitrogen 
supplied in the 1500 grams put into each pot, was only 0T035 gram. 
This series included 10 conditions as to manuring, each in duplicate. Each pot of 
experiments 1 to 8 received the complete mineral manure—No. 1 alone; Nos. 2, 3, 4, 
and 5, each with 0’3 gram of nitrogen as nitrate of soda; No. 6 with 0’2 gram 
nitrogen as nitrate of soda (half applied at the commencement and half a month 
later); No. 7 with 0*2 gram nitrogen as ammonium sulphate; No. 8 with 0'3 gram 
nitrogen as dried blood; No. 9 received farm-yard manure = 0*3 gram nitrogen, with 
mineral constituents sufficient to bring the mineral supply up to that by the complete 
mineral manure; lastly. No. 10 received at the commencement 0‘3 gram nitrogen as 
powdered hay, and later 0‘1 gram as nitrate of soda; the mineral composition of the 
manure being made up as in the case of the farm-yard manure. 
On May 25, 1884, 10 germinated seeds of buckwheat were sown in each of the 
pots, excepting those of Experiment 2, which received only 5, and those of Experi¬ 
ment 3 which received 15. On September 16 the plants were cut, and they and the 
soils were analysed, the duplicates being mixed as before. The results are given m 
the following Table. 
Series II.—Experiments with Sand as Soil. 
Experi¬ 
ments. 
Nitrogen. 
Crops, 
dry. 
Nitrogen. 
Nitrogen, 
gain or 
loss. 
• Manm'e.s. 
In 
Soil. 
la 
Manure. 
Total. 
In 
Soil. 
In 
Crops. 
Total. 
gi'- 
gr- 
gr. 
gr- 
gr- 
gr- 
gr. 
gr- 
1 
Complete mineral manure .... 
0-1035 
0-1035 
0-970 
0-1455 
0-0290 
0-1745 
+ 0-0710 
2 
Do., 
and nitrate soda .... 
0-1035 
0-300 
0-4035 
6-825 
0-3-270 
0-1405 
0-4675 
+ 0-0640 
3 
Do., 
do. .... 
0 1035 
0-300 
0-4035 
6-585 
0-3060 
0-1680 
0-4740 
+ 0-0705 
4 
Do., 
do. .... 
0-1035 
0-300 
0-4035 
5-890 
0-4080 
0-1375 
0-5455 
+ 0-1420 
5 
Do., 
do. .... 
0-1035 
0-300 
0-4035 
7-850 
0-2280 
0-2525 
0-4805 
-t 0-0770 
6 
Do., 
do. .... 
0-1035 
0-200 
0-3035 
7-612 
0-2280 
0-2420 
0-4700 
0-1665 
7 
Do., 
and ammonium sulphate . . 
0-1035 
0-200 
0-3035 
6-425 
0-1850 
0-2315 
0-4165 
+ 0-1130 
8 
Do., 
and dried blood. 
0-1035 
0-300 
0-4035 
5-600 
0-2685 
0-1375 
0-4060 
-t- 0-0025 
9 
Do., 
and farm-yard manure . . . 
0-1035 
0-300 
0-4035 
4-572 
0-4350 
0-1205 
0-5555 
+ 0-15-20 
10 
Do., powdered hay, and nitrate 
soda 
0-1035 
0-400 
0-5035 
1-225 
0-3570 
0-0390 
0-3960 
- 0-1075 
