1102 ARBORETUM AND FRUTICETUM. PART III, 
hours in the heat of the day, if there happen to be much sun at the time, 
This shading should only be continued till the young plants are enabled to 
bear the full heat of the sun. The soil for the first potting should be one 
half peat and one half sand, always taking care to drain the pots well with 
small pieces of broken pots or cinders. The second potting must depend 
much on the season of the year: if the first potting is done in the spring, the 
second should be performed as soon as the young roots appear round the 
inside of the pots; but, if the first potting is in the summer, then the second 
will not be necessary till the following spring. The soil for the second potting 
should be about two thirds peat and one third sand; and in all the after- 
pottings the soil should be the same as recommended below.” (Treatise on 
Cape Heaths, &c., p. 14.) 
The soil most suitable for Cape heaths, according to Mr. M‘Nab, is black 
peat, “taken from a dry heath, or common, which is never overflowed with 
water. In general, it should not be taken off more than 5in. or 6 in. 
deep. This, however, must partly depend on the subsoil; for, in some cases, 
at 12 in. or 14 in. deep, the soil is quite as good as at the surface. What- 
ever heath, or other vegetable production, is on the surface, should be taken 
along with the peat earth to the compost ground, and there laid up in a 
heap till wanted. It frequently happens that peat earth, taken from such 
situations, has sand intermixed with it in its original state; but, where this is 
not the case, a quantity of coarse white sand should be procured, and mixed 
with the earth in the compost ground. This should be, at least, to the extent 
of one fourth or one fifth of the whole: and, if it exceed this quantity, it will 
not be found injurious to the health of the plant.” Mr.. M‘Nab prefers “a 
coarse white sand, when it can be procured; but, when that cannot be had, 
any coarse pit or river sand will answer equally well; and, if an opportunity 
should offer of procuring sand from a freestone quarry, or from the hewings 
of sand stones used in buildings, that may be substituted ; but, in either case, 
the sand should be free from irony matter. When the earth and sand are 
properly mixed, the compost is fit for use.” (Treatise, &c., p. 16.) Whether 
compost for heaths or other plants should be used in a recent state, or after 
it has lain a year or two in the compost ground, and been frequently turned 
over, is a point on which cultivators differ in opinion. In the case of the. 
compost which Mr. M‘Nab recommends for heaths, he has found no difference 
whether it was used immediately when brought from the common, or after it 
had lain some time, and been turned over and mixed for years. Mr. M‘Nab has 
grown, in this soil, in tubs, 3 ft. over, the freer-growing heaths, such as Syringo- 
dea (H.) Ewerdna, abiétina, vestita coccinea, grandiflora, Bonplandiana, &c., 
to the height of 8 ft,; the plants being bushy in proportion, and, when in 
flower, covered with blossoms from the edge of the tub to the top of the plant. 
A small quantity of manure (viz. about one eighth part of rotten cow-dung) is 
frequently added by Mr. M‘Nab to the above compost ; which shows, contrary 
to the opinion of some, that, like other plants, heaths are capable of being fed, 
artificially, with food containing animal matter. Mr. M‘Nab has also tried 
liquid manure; but he is “ unable to give particular directions ” as to the pro- 
portions in which it should be used. Besides manure, which Mr. M‘Nab adds 
occasionally, he considers it a great advantage to introduce into the soil con- 
siderable quantities of coarse soft freestone, broken into pieces of from 1 in. 
to 4in. or 5in. in diameter. The quantity of stone which he introduces will, 
he says, “in most cases, if broken down into sand, and added to the sand 
previously in the soil, form about one third part of the whole mass.” The 
reason given by Mr. M‘Nab for introducing the stone is extremely interesting 
and important ; and, like every line in his most valuable treatise, it ought to 
sink deep into the mind of the young and thinking gardener : — “ When 
stones are mixed with the earth in the way above recommended, heaths 
will never suffer so much in the summer from occasional neglect in watering 
them, as they would do if the stones were not made use of; because these 
stones retain the moisture longer than the earth, and, in the winter, they allow 
