This section is from the book "A Dictionary Of Modern Gardening", by George William Johnson, David Landreth. Also available from Amazon: The Winter Harvest Handbook: Year Round Vegetable Production Using Deep Organic Techniques and Unheated Greenhouses.
Lime is valuable as a manure, for some one or more of its salts enter into the composition of every vegetable. But it is not the lime of every district that is suitable for the purpose. Some specimens contain a very large proportion of magnesia, which, absorbing carbonic acid very slowly, remains in a caustic state, to the injury of the roots of the plants, and the diminution of benefit from the carbonic acid evolved by the decomposing constituents of the soil. Neither can the gardener apply it to all his soils with advantage. Thus, peat and bog earth are beneficial to the plants grown upon them by their containing gallic and other acids which lime removes.
To garden soil of the usual staple about fifty bushels of lime per acre is a sufficient quantity. If the soil be clayey the quantity may be doubled. A very excellent manure is formed by mixing one bushel of salt with every two bushels of lime.
Lime cannot be applied to the soil too fresh from the kiln; for if allowed to absorb carbonic acid from the air, it is rapidly converted into chalk.
"It is astonishing how ignorantly neglectful are the cultivators of the soil, when their crops are devastated by the slug, not to dress them so as to render the surface of the soil quite white, during the promise of a few days' dry weather, with caustic lime. It is instant destruction to every slug it falls upon; and those that it misses are destroyed by their coming in contact with it when moving in search of food.
"It is a common practice to burn couch-grass, docks, gorse, and other vegetables, which are very retentive of life, or slow in decay; a more uneconomical, unscientific method of reducing to a state beneficial to the land of which they were the refuse, cannot be devised. In breaking up heaths, such exuvae: are very abundant; but, in all cases, if the weeds, leaves, etc, were conveyed to a hole or pit, and, with every single horse-load, and with barrow-loads in proportion, a bushel of salt and a half bushel of lime were incorporated, it would in a few months form a mass of decayed compost of the most fertilizing quality; the lime retaining many of the gases evolved during the putrefaction of the vegetable matter, and the salt combining with the lime to destroy noxious animals, which might form a nidus in the mass. By this plan nearly all the carbonaceous matters of the refuse vegetables are retained; by burning, nearly all of them are dissipated." - Principles of Hardening.
Lime rubbish is the old mortar and plaster obtained when brick buildings are pulled down. It is an excellent manure, abounding with the salts of potash and lime. It should be reduced to powder before spreading and digging in.