1818.] of burying Weeds. SI 



but little if any manure. Indeed the advantage of placing a 

 plant in its own soil is, that it will do with half that quantity. 

 When we are thoroughly persuaded and informed what plants 

 really can take nutriment from the root and those which cannot, 

 it will be a vast saving to the farmer ; for in fact very few sand 

 plants require manure. I should this summer have completed 

 the business of my trenches, and the trial of all agricultural 

 plants, in the five soils above mentioned, if a most severe illness 

 had not impeded my progress for some time. 



If a botanist is asked how are plants fed, he will probably 

 answer, without hesitation, " by means of the radicles which 

 draw from the earth the nutriment which is consigned to the 

 root for that purpose ; " but I wish to know how those plants 

 are to be nourished which have visibly and positively no radicles, 

 or extremely few ? Now this is the case certainly with two very 

 large collections of plants, the mountain plants and the sand 

 plants. If these vegetables, therefore, are not fed by the 

 radicles, they must be supported by the atmosphere : is it not 

 then of the greatest consequence to know which plants these 

 are? for if they are wholly or principally supported by the 

 atmosphere, they cannot certainly require manure. I think 

 these propositions follow of course, and cannot well be refuted : 

 to compare the root of a plant which requires a rich soil with the 

 root of a sand plant will at once show the difference. 



The size of the root is of no consequence whatever ; it is the 

 small threads which absorb the nourishment, and which alone 

 show the nature of the plant ; the turnip, carrot, and parsnip, 

 have hardly any of these. The plants of the barren rock have 

 also no radicles, and the root serves merely to fasten them to the 

 spot, and to form the corculum of the seed ; and this is so deci- 

 sive that in many annuals, among the sand and mountain plants, 

 the root is almost dead before the flower appears. 



I do not despair that the time will soon arrive when every 

 farmer will know the plants that exactly suit his soil, that he 

 will be able chemically to appropriate the manure to the soil, 

 and will be incapable of burying weeds and of turning in young 

 crops. I am, Gentlemen, your obliged humble servant, 



Agnes Ibbetson. 



Article III. 



On the Fountainkall Chalybeate Spring. By T. L. Dick, Esq. 



F.R.S.E. 



(To Dr. Thomson.) 



SIR, Fountainkall, Jan. 26, 1818. 



Referring you to my communications of April 13 and 

 July 9, 1816, on the subject of the FountainhaU Chalybeate 



