186 
THE BOOK OF LTME. 
small, and though each case required other 
special remedies also, I recommended, among 
the measures to be taken with the view of 
rendering them productive, the addition of 
lime in one form or another to them all. 
" I consider, therefore, that these soils con- 
tained less than arable land which derives no 
supply from any natural source ought to con- 
tain, if it is to produce healthy and abundant 
crops. 
" 3°. How much ought to be present? — To 
maintain a soil in the highest state of fertility, 
it is not necessary that it should contain so 
much as was found in the chalk and Athenian 
soils above described, nor so little as was pre- 
sent on those from Pinkie, Lynedoch, and 
Jamaica. These soils which are naturally 
most fertile, in all our cultivated crops, 
usually contain a considerably larger quantity 
than was present in these latter soils, — while 
those which naturally contain so small a pro- 
portion are almost universally improved by 
an addition of lime. Still, scarcely any pro- 
portion can be stated which will be really the 
most advantageous for any considerable num- 
ber of different soils. As a matter of opinion, 
however, I may state that I believe there are 
few soils to which lime, in the proportion of, 
or in quantity equal to, three per cent, of the 
carbonate will be too much— while, on the 
other hand, there are not many in which it 
will be of advantage to increase the proportion 
of carbonate beyond from six to ten per cent. 
— provided this carbonate be in a sufficiently 
minute state of division. 
" So much, however, as I have already 
said, depends upon the nature of the soil, — its 
locality, its stiffness, the state of drainage, 
the proportion of vegetable matter and of 
oxide of iron it contains, and upon the state 
of chemical combination and of mechanical 
division in which the lime exists in the soil, — 
that I should consider it necessary to inquire 
into all these circumstances in each special 
case before I ventured to give a decided opi- 
nion, as to the expenditure of lime and money 
for which a profitable return was likely to be 
obtained."— Pp. 55—60. 
The mechanical effects of lime upon the 
land are easily explained, as well also as the 
chemical changes which it makes. It opens 
and renders more free all stiff and clayey 
soils, and consolidates such as are light and 
sandy, and we are informed by the author, 
that in some districts it stiffens one half as 
much as clay would. With regard to its 
chemical effects, it increases the fertility of 
all lands in which lime does not already 
abound, and adds to the productiveness of 
such as are moist, tenacious, or abound in 
vegetable matter ; and some clays which will 
not produce without lime, will bring luxuriant 
crops of wheat with a moderate application. It 
lessens the cost of manure by rendering the 
smaller quantity more effective. We are told 
by the author that land, of the annual value 
of five shillings per acre has been rendered 
worth thirty or forty shillings by the applica- 
tion of lime alone. This is mentioned on the 
authority of a gentleman of considerable prac- 
tical experience, Sir John Sinclair, who men- 
tions large tracts, on the northern slopes of 
hill land above the Laigh of Moray, that have 
been tripled in value by the use of lime. The 
effects of lime on the crops themselves are 
explained at some length, and they are so im- 
portant that we must quote the section whole. 
" 1°. It alters the natural produce of the land, 
by killing some kinds of plants and favouring 
the growth of others, the seeds of which had 
before lain dormant. Thus it destroys the 
plants which are natural to siliceous soils and 
to moist and marshy places. From the corn- 
field it extirpates the corn-marigold ^Chrys- 
anthemum segetum), while, if added in ex- 
cess, it encourages the red poppy, the yellow 
cow-wheat (Melampyrum pratense), and the 
yellow rattle (Rkinanthus crista galli), and 
when it has sunk, favours the growth of the 
troublesome and deep-rooted coltsfoot. 
" Similar effects are produced upon the 
natural grasses. It kills heath, moss, and 
sour and benty (agrostis) grasses, and brings 
up a sweet and tender herbage, mixed with 
white and red clovers, more greedily eaten by, 
and more nourishing to, the cattle. Indeed 
all fodder, whether natural or artificial, is said 
to be sounder and more nourishing when 
grown upon land to which lime has been 
abundantly applied. 
" On benty grass the richest animal manure 
often produces little improvement until a 
dressing of lime has been applied. This is 
especially the case when lime is laid upon land 
for the first time. The physical improvement, 
even, is so marked that in some instances it is 
said the mere saving of labour in ploughing 
up would be sufficient to compensate a farmer 
for liming, were no other benefit derived from 
the application — from the. more perfect and 
economical manner in which he would be able 
to work his land. 
" It is partly in consequence of the change 
which it thus produces in the nature of the 
herbage, that the application of quick lime to 
old grass lands, sometimes before breaking up, 
is found to be so useful a practice. The coarse 
grasses being destroyed, tough grass land is 
opened and softened, and, as I have said, is 
afterwards more easily worked, while, when 
turned over by the plough, the sod sooner 
decays and enriches the soil. It is another 
advantage of this practice, however, that the 
lime, has time to diffuse itself through the soil, 
