BULLETIN OF THE BUSSEY INSTITUTION. 275 
the earth in the other two boxes. Maize and ray-grass were grown in 
all four boxes during the three months, at the end of which time the 
crops, though not yet mature, were harvested, and the weights of the 
dry products as well as their chemical composition, were compared. 
A few of the results of these experiments are given in the following 
table. The plants were watered with distilled water. Those grown 
in the earth rich in humus were in both boxes much better, larger, and 
greener than those grown in the sandy loam. Maize throve in the 
heated earth, and the grass supported the high temperature very well. 
But it was found by preliminary trials, that neither lupins, rape, nor 
oats prospered in the heated earth : — 
Exposed to the temperature of Exposed to the higher 
ordinary summer air. temperature. 
There was harvested 
from the 50 Ibs. of In the Loam | In the Humus | In the Loam j In the Humus 
earth: — Box, grms. Box, grms. Box, grms. Box, grms. 
Total Crop, dried at 
ead 8) SIO wo SACI ST eae eres ee a OU (ame aes 
ee LIC, olay tee le LOO tious pe PALL, 
DOR silsh a «is 28h . iG. Lat cs , SIS2i yrs : 7.96 
During the experiment 
the 50 Ibs. of earth 
lost: — 
Organic matter. . . ng ae" 1 eae eae Lee cles PSO alee re YG 
ere st oo | TO} 5 ARON ere ALDOR du + yay 
Eoin ech) ee 2.00* . A 5.25% . : 6.10 < pea by. 
The 50 lbs. of earth | 
contained before the 
experiment : — 
rermmAtberis wis | i. 700 .» «\{ . 12381 . . BRIT er LOLs Wecent. 
cas |. «| » CSO « « 1 GOST oe 6 OCU nts - 664. 
Piiretenewe. gears). 13.5. . - 24.00. 4g ARH SY Ie oe . 24.00 
Other examples of the consumption of soil-nitrogen by crops are to 
be seen in the experience of many countries where lime is habitually 
applied to the land, and in the results of field experiments like those 
of Lawes & Gilbert,f for example, in which large quantities of nitrogen 
* The risk of errors of observation due to the inherent difficulties of the 
investigation are to be kept in mind and allowed for, as well as the likelihood 
that some nitrogen may have been fixed in the soil in the manner alluded to on 
page 285. 
t “ Philosophical Transactions,” 1861, 151. 435. 
