410 Report of Experiments with different Manures 
The percentage of phosphoric acid, as well as that of potash, 
increases notably, though not in so great a degree, where the 
mineral manure containing it was used. 
The percentage of sulphuric acid in the ash is pretty uniform 
throughout, though it was supplied largely both in the ammo- 
niacal salts and in the mixed mineral manure. Whether or not, 
the whole of the sulphuric acid found, existed as such in the 
plant, in combination with bases, or whether, on the other hand, 
there has been any loss of it, or of sulphur in some form, during 
the incineration, may be a question. It is, at any rate, worthy of 
remark how very umch larger is the proportion of chlorine found 
in the ash of this succulent produce wherever it was used in 
manure, notwithstanding that this substance (chlorine) may b(^ 
supposed to be in a far less degree than sulphur or sulphuric 
acid, if at all, essential to the elaboration of the final products of 
the plants.* 
Carbonic acid is seen to be in the largest proportion in the 
produce grown without manure, and in that by mineral manures 
alone. The Carbonic acid is the product of the incineration of 
some other organic acid. Its comparatively large amount in the 
ash of the produce of the two plots mentioned is due to the 
Leguminous and other non-Graminaceous herbage, occurring in 
large proportion on those plots. The ash of such herbage (the 
non-Graminaceous) contains, indeed, little or no silica, and fre- 
quently a great deal of Carbonic acid due to salts of organic acids. 
The percentage of silica is, nevertheless, much higher in the 
ash of the produce grown without manure than in that grown by 
any of the artificial manures now in question. The percentage 
of silica in the ash is the less where the produce of the Grami- 
naceous herbage — which so peculiarly requires it— is the greater. 
And where the total Graminaceous herbage was thus the greater, 
it was also in the larger proportion in flowering and seeding 
stem ; and as the stem increases, so, when not in defect, does the 
proportion of silica. It is true that where the Graminaceous 
produce was so large, and the proportion of it that was in flower- 
ing and seeding stem was also large, those stems were not so 
ash is very much hicreasecl. This constituent, like soda, is found only seldom, 
or in small quantity, in the ash of perfectly-ripened vegetable prodxice. It pro- 
bably sen'es more as a vehicle of bases, than as an essential constituent of any of 
the final products of the organism. Were we to exclude it in all cases from these 
ash analyses, the percentage of potash would be higher where the animoniacal 
salts were used with the mineral manure, and the grasses were so much developed, 
than where tlie mineral manure was used alone. 
* The fact, that in such highly siliceous aslies the amounts of chlorine should 
not only in some cases be very large, but that the variations in amount should 
have such very obvious connection with the nianurial conditions supplied, is quite 
in accordance with the experiments of Mr. Way, showing that a loss of chlorine 
need seldom be feared when the process of incineration is carefully conducted. 
