if it were situated in a low plain or valley, but 
entails upon it a number of both consequent and 
accompanying disadvantages. Its grass lands 
yield a less succulent and nourishing herbage, 
and are slower in reproduction ; its cereal crops 
bear less plump grain, run more to straw, and 
are longer in ripening and more liable to acci- 
dents; its soils are more seriously washed away 
by heavy rains, and more deprived of their finest 
particles after every process of tilling and pul- 
verization ; its facilities for obtaining extraneous 
manures are much fewer, and its obstacles to 
every description of horse labour more numerous 
and stubborn ; its lands are colder, more denuded 
of argillaceous and calcareous powders, more 
eritty, gravelly, and churlish, and less fitted, in 
both mineralogical and mechanical condition, for 
producing wheat or the other valuable grains; 
and its whole economy is less compact within, 
less independent of exterior aids, and less freely 
connected with surrounding farms and the neigh- 
bouring markets. But the directly climatic in- 
fluence of altitude upon a farm is comparatively 
great. In latitudes 54° and 55° in Great Britain, 
an altitude of 500 feet above sea-level is the high- 
est at which wheat can be cultivated with any 
probability of profit; and even there, the grain 
is liable to be very light, and will frequently be 
a month later in ripening than such as grows on 
the neighbouring plains. In the same latitudes, 
an altitude of from 600 to 800 feet, according to 
the exposure, the nature of the soil, and other 
modifying circumstances, is the highest at which 
barley and oats can be profitably cultivated ; and 
in backward seasons, crops grown at these alti- 
tudes will be of small value, and will sometimes 
_ yield nothing but straw. Yet in the loftiest hills 
and second-rate mountains of the county of Wick- 
low in Ireland, rye has long been successfully cul- 
tivated on lands and in positions where barley 
and oats would be entire failures. 
On farms in high and humid situations in the 
lowlands of Scotland, or in the practicable parts 
of the Scottish highlands, the principal objects of 
husbandry ought to be good grass for pasture, 
and the securing of an ample supply of winter 
food for live stock; and the attainment of these 
objects ought to be sought by the improvement 
of grass lands, the wise management of hay-mea- 
dows, the cultivation of lands fit for producing 
turnips and other green crops for cattle, the 
growing of potatoes for the use of man, and the 
incidental production of grain crops in the or- 
dinary steps of rotation necessary for the most 
regular, permanent, and profitable supply of grass, 
hay, and turnips. See Grass, Lanps, PastuREs, 
Farms, Wastes, Drainine, IRR1e@arion, and other 
articles. In all such situations tillage is advis- 
able only in so far as it conduces to the produc- 
tion of turnips and hay, and the permanent im- 
| provement of the soil for pasture; and the crops 
_ of grain, which necessarily form parts of the ro- 
tation, can never be depended on for profit, ex- 
cept as yielding straw for the feeding and litter- 
ing of cattle, and for the preparation of suitable 
manure for turnips. The most suitable rotation 
is, first, oats from old ley ; next, turnips, and the 
necessary proportion of potatoes, with the whole 
of the manure produced on the farm; next, early 
oats or barley, sown with grass and clover seeds; 
next, hay ; and then a continuation of the grass 
into pasture during at least three years, and dur- 
ing as much longer a period as will comport with 
a due extent of the farm being under tillage for 
the raising of turnips and the full consumption of 
manure.—Keith’s Botanical Lexicon.—Humboldt’s 
Travels —Dr. Prout’s Bridgewater Treatise—M. 
C.F. B. Mirbel’s General Views of Vegetable Na- 
ture—Treatise on Planting in Library of Useful 
Knowledge—Sir John Sinelair’s Code of Agricul- 
ture—Sir John Sinclair's General Report of Scot- 
land. 
ALUM. A double salt, consisting of the sul- 
phate of potash and the sulphate of alumina. It 
is a white coloured, translucent salt, crystallizes 
in regular octahedrons, has a powerfully astrin- 
gent and somewhat acid taste, is usually sold in 
large crystalline masses, and makes a consider- 
able figure in the veterinary surgeon’s collection 
of drugs. According to the analysis of Berzelius, 
it consists of 34:23 of sulphuric acid, 10°86 of 
alumina, 9°81 of potash, and 45:00 of water. It 
dissolves in from 15 to 18 times its weight of | 
cold water, and in less than its own weight of 
boiling water. It is found native, as an efflores- 
cence from certain rocks and soils, and is made 
from various aluminous minerals. It is manufac- 
tured in very large quantities at Whitby in York- 
shire, and Hurlet in the vicinity of Paisley. Alum 
is a most important salt for the arts, especially in 
dyeing and colour- printing, forming the chief 
basis for light and bright colours. In medicine, 
it is a powerful astringent, and as such is used | 
both internally and externally. In a state of 
fine powder, it 1s sometimes externally applied, in 
veterinary practice, for stopping bleeding and 
destroying small excrescences, and sometimes 
blown through a quill into the eye for the re- 
moval of specks of long continuance. A mixture 
of alum, in doses of two drachms, with other as- 
tringents, is sometimes administered internally 
in cases of diarrhoea, diabetes, and hemorrhage; 
but, always in this form, and often in any form 
whatever, it is far more likely to be mischievous 
than beneficial. Alum lotion, made by dissolving 
from six to eight drachms of alum powder in two 
pints of water, is a frequent and tolerably effica- 
cious application for superficial sores, cracked 
heels, and mild forms of grease, but ought not to 
be used till the surrounding inflammation has 
been subdued ; and, in its weakest state, it is of- 
ten employed for the cure of wounds or ulcers in 
the mouth of animals, and of canker in the ear of 
dogs. A solution of alum, double the strength of 
this lotion, and rendered increasingly powerful by 
the addition of a small quantity of white vitriol, 
