906 Transactions.—Miscellaneous. 
been tried by many of us, but, I think, with unsatisfactory results. It does 
not stand the sea breeze, and it is in leaf for a comparatively short time of 
the year. We want something better than the Osage orange. 3 
Possibly from California or Oregon we might obtain the plant we re- 
quire, and with greater facility than from other countries, on account of the 
regular communication. 
There is a common New Zealand shrub, or tree, which may be made 
useful for shelter, viz., the Ngaio: but to bring it into common use for a 
hedge plant it must be raised in nurseries, and thus established with good 
roots before planting out. So long as we have to depend upon getting young 
plants from the outskirts of the bush, the greater number of them will be 
sure to die off after being transplanted. This will not suit for hedge 
planting, as the preliminary expense of preparing the ground is thus 
thrown away. 
The Ngaio is very hardy, is improved by pruning and clipping, and does 
not seem to be eaten by horses or cattle; but I am informed that sheep will 
eat it, although I have not myself observed them to do so. 
Art. XV.—Lime as Manure: Its Beneficial Effects when applied to the Culti- 
vation of the Soil. By D. Hay. 
[Read before the Auckland Institute, 2nd October, 1876.] 
Common limestone is composed of carbonate of lime, 95:05 parts; water, 
1:68; silica, 1:12; alumina, 1:00; oxide of iron, *75 per cent. The 
Whangarei limestone, which is said to contain from 96 to 97 per cent. of 
carbonate oflime, is therefore of superior quality. Lime from its strong 
attraction for carbonic acid and moisture may thus also be beneficial by 
affording a supply of both these to plants. Lime exists in nature and in 
the soil in a state of combination with carbonic acid. Limestone, however, 
before it can be rendered friable must first be burnt and reduced to a quick or 
caustic lime. In this state, on the addition of water, it readily pulverizes, 
and greedily absorbs carbonic acid from the atmosphere. Very few lime- 
stones or chalks, however, are pure, the primary marbles and calcareous 
spars being the exception. Clay, flint, magnesia, iron, and other salts are 
in a greater or less quantity found mixed in limestones. Slacked lime is a 
combination of lime with about a third of its weight of water, and is called 
a hydrate of lime, and when this hydrate, by exposure to air, becomes & 
carbonate, the excess of water is expelled. When freshly burned or slacked 
lime is mixed with any moist fibrous vegetable matter, there is a strong 
action between the lime and the vegetable matter, and they form a kind of 
