20 Green Vegetable Manure. 



nature ; but my object has been to consider the lombardy pop- 

 lar under the least advantageous circumstances, and to show its 

 value and importance in breaking the monotony of most planta- 

 tions Its combination with other trees, and remarks on them 

 individually, may become the subject of some future paper. 



I am, dear Sir, 

 Yours, &c. 

 No. 1. Wellington Street, John Thompson. 



Waterloo Bridge, Strand. 



Art. IV. Observations on an Hypothesis concerning the Effects 

 of Green Vegetable Manure. By Anthony Todd Thom- 

 son, M. D. F. L. S., &c. Author of Lectures on Botany. 



Dear Sir, 



In perusing the first volume of the Transactions of the Hor- 

 ticultural Society of London, I was particularly struck with 

 an hypothesis advanced by a gentleman, to whose labours in 

 Phytology the world is very largely indebted, Mr. T. A. 

 Knight, in a paper read by him before that society, " on the 

 advantage of employing vegetable matter, as manure, in afresh 

 state." The hypothesis referred to, assumes as a principle, 

 that plants thrive better on a soil manured with green-veget- 

 able matter, because " many vegetable substances are best 

 calculated to re-assume the organic, living state, when they are 

 least changed and decomposed by putrefaction." 



The grounds on which Mr. Knight has raised this hypothe- 

 sis are two, well-contrived experiments. In the first, the seeds 

 of the Plum vegetated, with uncommon rapidity, in pots nearly 

 filled with the fresh leaves and roots of grasses : in the second, 

 which was a more extended and an admirable comparative 

 experiment, turnips sowed on different portions of the same 

 field, differently manured, grew more vigorously in proportion 

 as the manure approached to the state of fresh-vegetable 

 matter. Thus, the crop was very forward and luxuriant on a 

 portion of the field on which green Fern had been employed 

 as manure ; less so on another portion on which fold and sta- 

 ble manure had been used ; and least forward on a third por- 

 tion, the manure of which was completely decayed dung. 

 The inferences drawn from these experiments, are endea- 

 voured to be further supported by Mr. Knight, by an ima- 

 ginary analogy between the assimilating functions of plants 

 and those of carnivorous animals, " who," he observes, " re- 

 ceive more nutriment from the flesh of other animals, when 

 they obtain it most nearly in the state in which it exists as 

 part of a living body." 



