676 The Sources of the Nitrogen of our Leguminous Crops. 
It is seen that tliere is more dry substance in the above- 
ground growth, but less remaining in the roots, in pots 2 and 3 
with the soil-extract, than in pot 1 without it. In the whole 
plant there is about 10 grams of dry substance in pot 1 with- 
out soil-extract, against about llf grams in pot 2, and more 
than 11 grams in pot 3, each with soil-extract. 
The point of chief interest is, however, that there was in 
one case more than twice, and in the other nearly twice, as 
much nitrogen in the above-ground growth in pots 2 and 3 
with the soil-extract seeding, as in pot 1 without it. But there 
was much less difference in the amounts remaining in the roots 
under the different conditions. Of nitrogen in the total vege- 
table matter grown, there is, in pot 2 nearly twice, and in pot 3 
more than 1^ time, as much as in pot 1 without the soil-extract. 
In pot 4 with garden soil, and with therefore full supply of 
already combined nitrogen, there was more dry substance pro- 
duced, and more nitrogen assimilated, than under the influence 
of the soil-extract seeding. 
The significance of the results relating to the nitrogen is, 
however, more clearly seen in the next Table (V.), which shows 
the amounts in the soil at the commencement and at the con- 
clusion of the experiment, and the gain or loss ; the amounts in 
the seed, in the total products of growth, and the gain ; the 
total nitrogen in the soil and seed at the commencement, in the 
soil and produce at the conclusion, and the gain. The Table 
also shows, in the last column but one, the nitrogen in the total 
products, reckoning the total initial nitrogen =1 ; and in the 
last column, the amount in the plants, reckoning that in the 
seed =1. 
Table V.— Peas, 1888. 
Nitrogen 
In saud or soil 
In seeds and produce 
Total 
In total 
pro- 
ducts, 
Utal 
initial 
= 1 
In 
planU, 
nitrogen 
iu aeied 
=1 
At com- 
mencc- 
uieut 
At con- 
clusion 
Gain 
(■-*-) or 
lo.SB (-) 
In seeds 
sown 
In total 
plants 
Gain 
At com- 
mence- 
meut 
At con- 
clusion 
Gain 
Pot 1 
Pot 2 
Pot 3 
Pot 4 
grams. 
O-O900 
0-(I909 
0-0999 
7-9989 
frrams. 
0-1(196 
(1-0974 
U(J818 
7-9989 
fxram. 
-f0(HI97 
_(|-||(I2.'> 
-00151 
K'ram. 
00293 
0-0298 
0-0291 
0-0301 
i;rain. 
0-2822 
0-5361 
0-1357 
0-6600 
pram. 
0-2529 
0-.iOti3 
0-4(IG6 
0-G299 
prams. 
0-1292 
0-1297 
01290 
80290 
grams. 
(1-3918 
0-G335 
0-5205 
8-6589 
pram. 
0-2Ci2G 
0-5(138 
0-3915 
0-6299 
3- 03 
4H8 
4- 01 
1-08 
9-61 
17-M 
14-97 
21-91 
The first point to notice is that there is very little difference 
in the amount of nitrogen in the sand or soil at the commence- 
ment and at the conclusion of the experiments. There would, 
