1310 
MESSRS, j. B. LAWES, J. H. GILBERT, AND M. T. MASTERS, 
not at all, or in very small quantity, on the manured one. Among those which were 
comparatively prominent on the unmanured, but which were scarcely represented on 
the manured plot, 5, Plantago lanceolata especially, and the several species of 
Ranunculus , may be noted. 
Upon the whole, the result of the annual application of a relative excess of ammonia- 
salts, without mineral or ash-constituents, the plants having thus to rely exclusively 
on the resources of the soil for these, is greatly to reduce the total number of species, 
especially of the Miscellanese, and to reduce the actual quantity grown, not only of the 
collective Miscellanea, but of every individual species occurring in any degree of 
prominence. Leguminosse are almost banished ; and although the number of species 
of grasses occurring in greater or less amount is nearly the same as without manure, 
by far the larger proportion of the whole produce consists of two grasses only— 
Festuca ovina and Agrostis vulgaris. These two have increased in both proportion 
and amount, whilst all others have diminished in a greater or less degree; and of these 
two, which have increased, the poorer Festuca ovina , has done so in by far the larger 
proportion, contributing in the fourth separation-year more than half the total produce, 
whilst Agrostis vulgaris supplied nearly 30 per cent, of it. 
Thus, with a supply of nitrogen in the form of ammonia-salts, in which it distri¬ 
butes in an available condition much less rapidly and widely than when applied as 
nitrate of soda, the herbage has come to consist almost exclusively of a very few 
comparatively superficially rooting species, and the result was, as has been already 
referred to, and as will be illustrated in detail in Part III., that the collective herbage 
was able to take up even less of some of the mineral constituents in the later years 
than that without manure, which comprised a very much more uniform mixture of a 
large number of species, of varying habits of growth, and of varying range of food 
collection. 
3. Nitrate of soda, alone; Plots 15 and 17. 
The application of nitrate of soda did not commence until the third year of the 
experiments (1858). For 18 consecutive years, 1858 to 1875 inclusive, plot 15 
received 550 lbs. of nitrate of soda per acre per annum, estimated to contain the same 
amount of nitrogen (about 86 lbs.) as the ammonia-salts applied to plot 5. Over the 
same period of 18 years, plot 17 received half the amount of nitrate, as it was then 
found that, with the larger amount of nitrate, there was scarcely any more increase than 
with the smaller, and that the proportion of the nitrogen supplied which was recovered 
in the increase of crop was much less where the larger amount was used; the application 
of nitrate to that plot was discontinued after 1875, the eighteenth year, and in, and 
since, 1876, a mixed mineral manure, including potass, has been applied instead. The 
object of this was, first, to determine whether or not, uuder these circumstances, any 
material proportion of the hitherto unrecovered supplied ‘nitrogen would now be 
recovered; and, secondly, to ascertain how far the character of the vegetation in 
