INTRODUCTION. 
about half its own weight of coarse sand; if poor, enriched with 
~ a third of its own weight of sifted leaf-mould. Manure, too, is 
invaluable, but it must be old (spent stuff from a hotbed is most 
useful) and it must be very finely pulverised. It should only be 
employed, too, in the proportion of an eighth or tenth to the 
whole composition. Peat must be used with care, it has a sad 
tendency to cake and consolidate, whereas the ideal rock-garden 
mixture should be at once nutritious, light,and spongy, not clogging 
in winter rains, nor yawning under summer suns, but always cool 
and friable and loose in the hand, like the consistency of a rich 
and perfect seed-cake, crumbling yet unctuous to the touch. For 
this end sand is the great standby, and should be employed with 
freedom in every mixture, being especially necessary, and in 
specially large doses, wherever peat is to be employed. Whatever 
the mixture, it should thoroughly be dug together, compounded, 
and blended; then it should be lightened by caraway seeds to 
taste, in the form of a liberal admixture of chips, either limestone, 
sandstone, or granitic. These should be about the size of the 
top-joint of any and all your fingers, and may be employed in 
different proportions to your pleasure, according as you desire 
merely to lighten your soil, with a sixth or tenth part of chips, 
or to approximate it to moraine by using an equal bulk of stones 
or even more. Here each garden and each taste will dictate its 
own composition, and each gardener will adventure for himself 
in the boundless land of experiment. But the general depth of 
soil should not be less than 24 feet, and need not be more than 33, 
while the central core of the mound, or foundation of the slope 
(no less than their base), must never be of hard and impermeable 
loam or dumped rubbish, but always of very coarse and perfectly 
open drainage rubble. 
Good mixtures, generally speaking, are as follows: 
4 loam, { leaf-mould, $ coarse sand—an excellent compound 
for the common run of alpines. (Lime to taste.) 
+ loam, 4 old mortar-rubble, + leaf-mould, + sand. A mixture 
of at least equal merit, pre-eminent where specially cal- 
cicole plants are in question. 
XXVill 
