<302 MESSRS. J. B. LAWES AND J. H. GILBERT ON" THE RESULTS OF 
the percentage composition of the different kinds of herbage, and in the amounts of 
constituents they respectively take up, will be further illustrated as we proceed. 
2. Ammonia-Salts alone; Plot 5. 
Over the same periods of 10 years, 10 years, and 20 years, the following results 
were obtained by the annual application of ammonia-salts alone, at the rate of 400 lbs. 
per acre per annum, estimated to supply about 100 lbs. of ammonia, corresponding to 
about 82 lbs. of nitrogen ; and, for comparison, the results obtained on plot 3, without 
manure, are also given. 
d able III.—Average, per acre per annum, by 400 lbs. Ammonia-Salts alone; Plot 5. 
Average per acre per annum. 
Plot 3. 
Plot 5. 
Without 
Ammonia-salts 
x lot o. 
manure. 
alone. 
+ or — plot 3. 
Hay. 
1 
lbs. 
lbs. 
lbs. 
First period, 10 years, 1856-1865 . 
2531 
3420 
+ 889 
Second period, 10 years. 1866-1875 . 
2236 
2471 
+ 235 
Total period, 20 years, 1856-1875 . 
2383 
2946 
+ 563 
Second period, per cent. + or — first period . 
-11-7 
-27-7 
Nitrogen. 
First period, 10 years, 1856-1865 . 
35-1 
57 - 9 
+ 22-8 
Second period. 10 years, 1866-1875 . 
30-9 
47-3 
+ lb'4 
Total period, 20 years, 1856-1875 . 
33-0 
52"6 
+ 19-6 
Second period, per cent. + or — first period . . 
-12-0 
-18-3 
Mineral Matter (Ash). 
First period, 10 years, 1856-1865 . 
148-5 
181-2 
+ 32-7 
Second period, 10 years, 1866-1875 . 
126-1 
108-9 
-17-2 
Total period, 20 years, 1856-1875 . 
137-3 
145-1 
+ 7-8 
Second period, per cent. + or — first period . 
-15-1 
-39-9 
Compared with the produce without manure, ammonia-salts alone have given an 
average annual increase over 20 years of 563 lbs. of hay, or, in all, of 11,260 lbs., or 
rather more than 5 tons ; and it is to be observed that the increased growth was 
dependent for the necessary mineral constituents (sulphuric acid and chlorine only 
excepted) on the supplies of the soil exclusively. But, whilst the average annual 
increase was 889 lbs. over the first 10 years, it was only 235 lbs. over the second 
