380 
Portable Manures—Potash as a Manure for Wheat. 
Portable Manures, containing great strength in small 
compass■. 
These are very valuable to the farmer at a distance 
from towns, one load being, in many cases, sufficient 
for several acres. They generally force or forward the 
crop, without doing much to enrich the soil with 
humus. 
Salt, 1 ton (value 25s.) is enough for 10 to 29 acres 
top dressing; though much more is used when plowed 
in to kill weeds, &c. For this purpose a ton may go 
to 3 or 4 acres. 
Soot is an excellent top dressing, twenty bushels per 
acre ; perhaps still better with two or three cwt. salt, 
just damped to prevent flying about in spreading. It 
should be sown upon wheat in calm evenings, when 
rain is expected. 
Gypsum, on clover, when wet with dew or rain, and 
the weather clearing, that it may stick on the leaf; 5 
or 6 cwt. per acre. 
Bone-dust, excellent to drill in with turnip seed, 10 
to 30 bushels per acre ; and better mixed with half or 
quarter as much wood ashes. A top dressing of the 
turnips, after hoeing; of gypsum, 3 cwt. and salt 1 cwt. 
per acre, would probably help the bone-dust. 
Nitrate of soda, and some other more expensive ma¬ 
nures, seem to pay very well, when judiciously used; 
but the object of this paper being to help the small 
farmer forward, with but little outlay, they need not 
be dwelt on here. 
It will be well, however, for the farmer, to know 
that lime, in compost with three or four times as much 
ditch or pond mud, laid out not very thick, and occa¬ 
sionally turned, gradually produces nitrate, more or 
less, according to the quality of the mud. 
I am, Sir, yours, &e. &c. 
13th Sept. 1842. J. Prideaux. 
Potash as a Manure for Wheat. 
Mr. \V. M. Chatterley delivered his ninth lecture at 
Havering Bower, near Rumford, on Monday, 19th ult. 
on Saline Manures, in continuation. 
The subject first spoken of was the manures con¬ 
taining potash as a base, those of soda having been 
treated in the last lecture. Potash was shewn to be 
present in every crop—nay, in almost every plant, 
more particularly in white crops which contained silica, 
(sand or flint) in considerable quantity; and most of 
all was it essential for wheat, as that plant contained, 
of all crops, the largest per centage of silica, and by 
potash alone could silica be taken into solution, so as 
to be absorbed and circulated with the sap of the plant, 
and subsequently deposited with its tissue. Moreover, 
it had been of late years discovered that those soils 
which yielded the most abundant wheat crops, always 
contained the larger quantity of potash, and that clay 
soils contained it naturally in considerable quantity— 
that is, considerable in proportion to the quantity re¬ 
quired ; for, it was -well worthy of remark, that the 
quantity of potash contained in the wheat was by no 
means sufficient for the solution of the quantity of sili¬ 
ca existing in the plant, and this led to the belief that 
the potash which conveyed the silica in solution to the 
plant, was returned to the soil, after having deposited 
its burden, and there again acted the part of a solvent 
for a fresh portion of silica, again to be conveyed to the 
crop. Wheat, unless supplied with a sufficiency of 
soluble silica, could not grow strongly and healthily; 
lienee the necessity for the presence of potash, in order 
to its abundant supply; but not potash alone, but pot¬ 
ash (itself an alkali) in union with an acid to neutral¬ 
ise its caustic properties, and form a salt. Thus car¬ 
bonate of potash (the pearlash of commerce.) and 
nitrate of potash (nitre or saltpetre ,) were useful as 
manures in soils deficient of potash. The source 
whence these might be obtained most cheaply by the 
agriculturalist requiring potash, and the value of each 
as a manure, was the next point for consideration. 
With respect to pearlash or nitre, the price would pro¬ 
bably exclude them from general or extensive use ; but, 
if we look to the sources whence they may be obtained, 
we shall find them, for the most part, within the reach 
of all. The pearlaslies of commerce are obtained 
from wood ashes in such countries as Canada and 
Russia, abounding in forest land. The ashes of various 
kinds of trees, shrubs, and herbs, contain quantities of 
this salt, varying from less than 1-10, as in the beech, 
oak, and elm, to about 74 per cent., as in the worm¬ 
wood. Herbs contain more than shrubs, shrubs more 
than trees, while the leaves and branches of trees con¬ 
tain more than the woody portions. Wood ashes, be¬ 
sides, contain varying quantities of silica, phosphate 
and carbonate of lime and magnesia, all highly useful 
for plants, containing matters which are the direct food 
for plants, as might readily be supposed, inasmuch, as 
they are themseives the ashes of plants. Can potash 
be always obtained in sufficient quantity by these 
means ? There are the hedge rows, bottoms, and 
woodland, unfortunately too frequent upon the general¬ 
ity of farms, which it is desirable to remove as much 
as possible; by burning these and mixing with the 
dung, or spreading over the land without much mixture, 
much benefit might be derived. But another question 
arises—Is it economical to consume so much vegeta¬ 
ble matter which might be used as manure, if the seeds 
were prevented from germinating and the substance 
broken up, as might be effected by means of lime on the 
draining of the farm-yard ? The one method or the 
other, or in fact both, are at the option of the agricul¬ 
turist, as he may be in want of either, or may find 
each the cheaper or more convenient. Carbonate of 
potash is deliquescent (attracts moisture;) the same 
remark will, therefore, apply to this salt as was made 
with regard to those deliquescent salts mentioned in 
the last lecture. 
With regard to nitre, a considerable supply would 
be procured by the mixture of lime and vegetable mat¬ 
ter left in contact for some length of time, which 
produced a decomposition of the vegetable matter, the 
carbon of which being converted into carbonic acid, 
united itself to the lime and formed chalk ; while any 
portion of nitrogen which it contained^ together with a 
supply obtained from the atmosphere, was, by the in¬ 
fluence of the lime, induced to unite with the oxygen of 
the atmosphere, forming nitric acid; the nitric acid 
then combined with the lime to form nitrate of lime, 
and with any portion of potash that might be present 
to form nitrate of potash. By this means it may be ob¬ 
served that nitrogen and potash are both supplied at 
the same time, and to the nitrogen must be attributed 
a large share of the fertilising effect of the salt; and 
this leads us to the consideration of the other saline 
manures which contain nitrogen. Nitrate of soda 
is nothing more than another native nitre with soda in¬ 
stead of potash as the base in union with nitric acid; 
it is, perhaps, yet to be decided which of these two 
possesses the most fertilising properties, though the pre¬ 
ponderance (especially for crops that contain potash,) 
is perhaps in favor of nitrate of potash. The differ¬ 
ence of price will decide which will be used by the 
farmer: but it seems more than probable that other 
and cheaper sources of nitrogen will be chosen when it 
is desirable to supply this substance in a saline form. 
Farm-yard manure, and animal matter in general, as 
nightsoil, urine, blood, and guano, have already been 
