The Gardener's Magazine 19:140 (1843)
Giuseppe Manetti, Monza, Dec. 7, 1842.

Charcoal and Charcoal Dust. — In your Vol. for 1841, p. 254-5., it is said, speaking of charcoal and charcoal dust, that M. Lucas was the first to show the action exercised by the charcoal on vegetation; thus setting aside the Italians, among whom the Abbé Piccone and Professor Moretti have treated of it at length in vol. 2. of the Biblioteca Agraria, p. 70.

The Gardener's Magazine 19:185-186 (1843)
Giuseppe Manetti, Monza, Feb. 5, 1843

Use of Charcoal in the Culture of Plants. — The following is the extract from the 2d volume of the Biblioteca Agraria of Professor Joseph Moretti and Carlo Chiolini, respecting wood charcoal, which I mentioned in my letter of the 7th of December, [p. 140.]

"From numerous experiments made by the Abbé G. Piccone, this substance [charcoal] is considered as an efficacious manure. It consists principally of oxide of carbon, the primary element of vegetable productions, and is, therefore, undoubtedly calculated to be employed for the purpose specified. According to the above author, every sort of charcoal, whether of oak, chestnut, or of any other sort of wood, the refuse of the charcoal, the small particles, or still better the dust, can be used as manure for every species of plant and in every soil. The charcoal of close grained wood, therefore, should be the richer in nutritious particles, as it contains less ashes and earth. The effect is more speedy and vigorous according to the fineness of the pulverisation of the charcoal; if it is coarse the effect is weaker but more durable. When the charcoal is intended to manure a field for several years, or the roots of vines and fruit trees, it is not necessary to pulverise it very fine. It is sufficient in such cases to triturate it so that the largest pieces may not exceed the size of a vetch. The means used for triturating the charcoal are, the olive presses, mallets, and large pestles of iron or heavy wood, suspended from a beam of wood like that of turners' and many other machines. The dust which is produced during trituration is easily laid by sprinkling it with water. When the pulverised charcoal is to be used in flower-pots, in furrows, in seed pans, or in seed beds, it is sprinkled on the surface and incorporated with the spade or with the watering-pot. This may also be done after the plants have germinated, and are 2 or 3 inches high, according to the nature of the species. In sown fields the same method is followed in applying it as with manure. Therefore, in treating ground burnt up by the sun, according to the opinion of the Abbé Piccone, it is laid on the ground towards spring, when French beans are to be sown, to preserve them from drought; to these succeed common beans, and afterwards wheat or any other grain without manure. In soils less arid, the rotation is begun with potatoes, hemp, buckwheat, and wheat. In every case the seed should be used sparingly. On artificial meadows charcoal dust is sprinkled in spring on the surface, as is practised with chalk and lands containing saltpetre. As to the quantity, the Abbé Piccone computes about an equal weight between charcoal and woollen rags, skins, and even scrapings of bones: a rubbo (about 18 lb. avoirdupois) of charcoal to two of new urine; three of night-soil well digested; four of fresh, and six of common, manure. After this, he advises, for olive grounds, vineyards, orange gardens, or orchards, to allow an interval of four years for the first time, five for the second, and six for the third, and so on between every manuring, taking care always to increase the quantity according to the growth of the trees."