hot seen, and the whole crop seems to be rye-grafs, although, in fact, there is as much clover as if it had not been manured at all.

This is a very fatisfactory proof of the influence of one manure in promoting the growth of a particular plant in preference to that of another. There are no doubt many others that the farmer is at present ignorant of.—I shall suggest a few.

It conftantly happened, that, where a heap of foot has lain fo long upon the ground as to deftroy all the plants upon its furface, the first plant that appears afterwards is the common couch-grafs *.

It as univerfally happens, that the first plant that appears where a heap of common ftabledung has lain, is the common knot-grafs †.

Sain-foin thrives upon the thinneft limeftone, gravely, or chalky foils, with great luxuriance,

* Triticum repens: † Polygonum aviculare:

luxuriance, even where these are so poor as to afford a very scanty crop of other forts of grass.

On much richer foils, that are not fo highly impregnated with calcareous matter, that plant only languifhes-on maoccafions it dies entirely.-Hence fainfoin is a most valuable crop in chalky countries,-in others it is juftly thought of no

ny

value.

Lime feems to promote the growth of rye-grafs in a higher degree than it does the growth of feather-grafs.-For, in fields that naturally abound with this laft, and in which it even gets the better of rye-grass when it is fowed,-if the ground be limed, the rye-grafs flourishes and destroys the other; and, when that fails, it is fucceeded by white clover and the poa-graffes, rather than by the feather-grafs.

XLII.

There is reason to suspect that certain manures which operate moft powerfully upon fome foils, do not promote the fertility of other foils in the fmalleft degree.-It would furely be of great use to the practical farmer to be made acquainted with these peculiarities.

In the part of the country where I was born, and first practifed agriculture, no manure whatever produced fuch a powerful and lafting effect as horn fhavings.-Compared with the best yard (midding) dung, in the proportion of one ftone of shavings to a cart

load

load * of dung, the effect of the first was, at the beginning, about equal, but, after the it was greatly fuperior.

firft

crop,

pearance

In the place where I now refide, I have found the effect extremely different.-A field of a good loamy foil, little different in apfrom those on which I had formerly laid this manure with fuccefs, was fallowed, and got a thorough dreffing of horn fhavings. It has fince that time carried feven crops of corn and grafs; but I have been able to perceive no fenfible effect of the manure on any of these crops. There has hardly been even a single tuft of grain more bushy and strong in one part of the field

than

*Nothing is fo indefinite as a cart or waggonload of things of this fort, that are not commonly weighed or measured; therefore, it were to be wifhed that writers on agriculture would endeavour to define them accurately. The cart load here meant may be a quantity between thirty and thirty-fix bufhels.

than another ;- a circumftance that could hardly be avoided in ufing this manure, from the impoffibility of spreading it fo equally as is neceffary.

Common falt is another manure that I have tried almost with the fame fuccefs. It is well known, from numberless well authenticated experiments, that the most ordinary effect of this manure is, to promote the fertility of the foil in a very fenfible degree, for a fhort time, when used in moderate quantities, and to check the vegetation of every kind of plant for a certain period, if employed in an over proportion.

To try the effect of it upon my own particular foil, I fixed a pin in the middle of a plot of grafs in the month of May,-and round that, as a centre, defcribed a circle of two yards diameter.-Around the inner circumference of that circular line, I ftrewed fome common falt very thin, making it gradually thicker and thicker as it came towards

the