254 ON FORCING THE HYACINTH. 



flowered at Christmas. Others are planted at the end of Octoher, 

 and the last succession about the middle of November. The pots 

 upright thirty-two's, about seven inches deep and four inches wide; 

 the soil half road-sand and half leaf-mould, with good drainage, the 

 bulb gently pressed into the soil above the brim of the pot. They 

 are placed on coal-ashes, in any open spare part of the garden, covered 

 eight inches with old tan or leaf-mould, as a rustiness, or canker, 

 was produced on the young leaves and flowers by coming in contact 

 with coil-ashes. In eight or ten weeks they will generally be found 

 in a fit state to be removed to the greenhouse, or any cold pit. From 

 thence the most forward are removed to a house in which the tem- 

 perature is kept from 60° to 65°, and placed about eighteen inches 

 from the glass. If any showed indications of expanding their flowers 

 before the stem was of sufficient length above the bulb, a piece of 

 grey paper, of the desired length of the stem, was wrapped around 

 the pot, and then placed in a cucumber-frame, with the temperature 

 from 10° to 75°. In the latter end of December, or early in January, 

 they rise six or eight inches in about ten clays ; if later in the season, 

 they advance quicker. When fully expanded, they are taken to the 

 temperature of 60°, and finally to the greenhouse. He adopts the 

 same practice with them when grown in glasses ; first placing them 

 in a dark room, to encourage the protrusion of roots, with a change 

 of water once a week until they are removed into the frame or forcing- 

 house, when a fresh supply should be given every day. The con- 

 stituent elements by which plants are supported was thus explained : 

 — That carbon is obtained by them in the form of carbonic acid gas 

 derived from the atmosphere, generated there by the respiration of 

 animals, and in the soil by the decay of vegetable matter; and this 

 with its compounds is absorbed by the roots, and inhaled by the 

 leaves. When acted upon by heat and light, the carbon is retained 

 and the oxygen evolved. Among many other observations, he re- 

 marked that the roots of plants appropriated for their own support 

 the nutritious matter contained in the water, that the residue causes 

 putrefaction, and generates animal cula destructive to the roots and to 

 vegetable life. Hence the necessity of changing the water when the 

 Hyacinths are in a rapidly-growing state. He produced on the table 

 two fine specimens grown in glasses. In one of the glasses a table- 

 spoonful of charcoal was mixed with the water, and in the other the 

 same quantity of chalk, (the carbonate of lime ;) by which experi- 



