Agricultural Chemistry. 
455 
Taiu.e II. — Sinmnarij of E.xpeiiments ou tlie Growth of Barley. 
-Vverage Total Produce (Corn and Straw) per acre, in 11)S. 
General Comlition of Manuring. 
Total 
Produce. 
Total 
Increase by 
Nitrogen. 
Barn-field — Harvest 1854. 
Ditto (ditto) with Ammonia-salts 
Ditto (ditto) with Nitrate of Soda .. 
lbs. 
2474 
7382 
8005 
lbs. 
4908 
5531 
Hoos-field— Harvest 1854. 
Ditto (ditto) with Ammonia-salts 
Nitrate of Soda (second year without Minerals) . . 
4656 
8127 
81.50 
7400 
3471 
3494 
2744 
In this Table it is seen that the mean total produce (corn 
and straw together) of barley in " Barn-ficld^^ on the previously 
mineral-manured plots, is 2474 lbs. ; that on land in similar 
previous condition, but with ammonia-salts now added, is 7382 
lbs. ; and that with nitrate of soda instead of ammonia-salts, 
is 8005 lbs. 
In " Hoos-Jield " again, the mean total produce of the series 
manured annually with direct mineral manures, is 4656 lbs. ; 
that with ammonia salts in addition, is 8127 lbs. ; that with 
(besides the minerals) rape-cake, equal in its amount of nitrogen 
to the ammonia-salts of the previous series, is 8150 lbs. ; and 
that with nitrate of soda, this being the second year of its appli- 
cation without mineral manure, is 7400 lbs. 
Here then, in both fields, we have an enormous increase 
of produce in the barley crop, by means of available nitrogen 
supplied to the soil. And although, owing to the more limited 
range of the underground feeders of the barley plant, and to the 
much shorter period of time during which it collects its mineral 
food, direct mineral manures have a more beneficial influence 
upon that crop than upon wheat, yet it is obvious, that as with 
the wheat crop so also with barley, a maximum agricultural pro- 
duce cannot be obtained, however liberal the supply of minerals, 
unless there be, at the same time, an accumulation of available 
niti'ogen icithin the soil itself. 
We now turn to a consideration of Baron Liebig's treatment of 
our recorded experiments and conclusions in reference to the 
growth of turnips. He says : — 
"It seems to mc worth while to consider hero one more of those iimneaning 
practical experiences, made by one who is, according to Jlr. Buscy, the first 
