258 Mrs. Ibbetson flu the [April, 



zine, that the earth furnishes matter for filling up the seed ; 

 and this nutriment probably is derived chiefly from the deca^ 

 of the underground plants : great patches * of this nutritive 

 matter are often, to be found in the root. 



I have now several trenches in several different; soils, and I 

 hope to give a further account, on a future occasion, which will 

 render the subject more perfect. It appears to me of such conse- 

 quence to agriculture and gardening, that I cannot help inviting 

 gentlemen interested in this department to repeat my experi- 

 ments, as they might very likely obtain from them more accurate 

 results. I shall certainly not leave the matter till I ascertain the 

 quantity of mould that may be gained from a given weight of 

 vegetables. 



It is admitted that some earths require less lime than others 

 for this process ; clay, for example, often contains pools of 

 putrid water, which causes it to decompose vegetable matter 

 much faster than any other earth ; while in chalk all vegetables 

 will last longer. In. repeating the experiments, great care must 

 be taken that the trough is well covered in, after being opened ; 

 for if water can enter it, and the earth is not well pressed 

 together, it spoils the whole experiment ; the soil should always 

 be left in its common state of pressure, neither more or less, and 

 not be subject to any rill of water. 1 have had several different 

 trenches in one soil ; but they have all given the same result, 

 except in clay, where putrid water got to the leaves of cabbages 

 and decomposed them in five months ; I have now made one 

 which shall remain tiil the vegetables become converted into 

 mouldy if I live so long. I have also made them in different 

 soils, and hope to gain s ome knowledge from the comparative 

 results rn the course of the next two or three years. 



It lias been objected to me that the small quantity of vege- 

 tables in my trough was the cause of their not fermenting ; but 

 it was certainly much larger than gardeners, or farmers, ever put 

 in one place to make manure. One of my trenches was as much 

 as three feet deep, and of course held a very large quantity of 

 weeds. It is, however, the principle to which I appeal, that 

 either heat, moisture, or air, is absolutely necessary to ferment- 

 ation ; and that they can be acquired by the plants when buried 

 in the earth only by accidental circumstances. I had a very 

 large hole dug in the earth, and placed there a quantity of hay, 

 that was heating in such a manner it was expected every mo- 

 ment to take fire ; it was thoroughly covered, and all air 

 excluded; it totally suspended the fermentation, though that 

 which was spread in the air continued to smoke, and turned 



♦ This powder is so completely to be traced in a tree at the time of seeding, 

 that if the stein is cut every inch from the root, it may be followed all the way 

 up to each separate twig in apertures made on purpose in the pith, and coloured 

 with the powder. 



