MESSRS. J. B. LAWES AjSTD J. H. GILBERT OR - THE RESULTS OF 
phosphoric acid, sulphuric acid, and chlorine, as well as more silica, lime, and soda, 
taken up ; and, with these, more carbon assimilated. 
In reference to the differences in the mineral composition of the hay grown under 
different manurial conditions, and accordingly possessing very different botanical and 
other characteristics, it is to be borne in mind that the dry matter of the species of the 
“ Miscellaneous” orders generally contains a higher percentage of mineral matter than 
that of the leguminous herbage, and the leguminous a higher percentage than that of 
the gramineous herbage ; and, further, that the less matured the produce, the higher, as 
a rule, will be the percentage of mineral matter in its dry substance. Again, the ash of 
the leguminous herbage contains the highest, that of the miscellaneous a lower, and 
that of the gramineous the lowest percentage of lime. On the other hand, the ash of 
the gramineous herbage is richer in potass than that of either the miscellaneous or the 
leguminous, and it will be the richer in potass, and the less rich in lime, the greater 
the proportion of stem to leaf. Hence, we should expect, as we find, less lime and 
more potass in the coarse, almost exclusively gramineous, and stemmy herbage. 
In conclusion, although with the mixed mineral manure and the double amount 
of ammonia-salts the large average amount of about 3 tons of hay has been annually 
obtained over a period of 20 years and more, and an even somewhat larger proportion 
of the supplied nitrogen was taken up than when only half the quantity was applied, 
there was not a corresponding increase in the amount of vegetable matter grown. 
There was, nevertheless, annually much more nitrogen, and much more of every one 
of the mineral constituents, supplied in the manure than was contained in the increase 
of crop. That the produce was not greater would appear, therefore, to be due to other 
conditions than a deficiency of any of the constituents derived from the soil, unless, 
indeed, of silica in an available form. It was more probably due to defective atmo¬ 
spheric, that is climatic, conditions, limiting the assimilation of carbon ; in other words, 
to a limitation in the amount, and adaptation, of the light, heat, and moisture, necessary 
for the assimilation over a given area of a larger amount of that substance. And, as 
there has been, not only a less amount of growth in proportion to the nitrogen taken 
up, but, notwithstanding an annually increasing manurial residue within the soil, a 
more or less declining amount over the later years, it would appear not improbable 
that, with the characters of the herbage described, there has been a less capability of 
the plants, either to gather up the accumulating stores within the soil, or to take full 
advantage of such atmospheric conditions as did exist. 
10. 550 lbs. Nitrate of Soda, with Mixed Mineral Manure containing Potass ; Plot 14. 
We have already compared the effects of a given amount of nitrogen applied as 
ammonia-salts with those of the same amount applied as nitrate of soda, when each 
was used alone. We have now to compare their effects when each is employed in 
conjunction with the usual “ mixed mineral manures.” The comparison will be between 
