ON THE FOOD OF PLANTS. ] J 



this highly- favoured district, that the farmers commonly re- 

 ceive 100 for 1 upon their seed. 



In my experiments, No. 10, we see, by the luxuriant Vegetable 

 growth of the cabbage and the wheat, what vegetable mat- matter * 

 ter can produce. For in neither of these could any kind of 

 nutriment be derived from the quartz sand in which they 

 spread their roots. 



The same kind of sand, in the vicinity of Barcelona, is Its importance 

 by the assistance of a bright sun and copious irrigation ren- 

 dered exceedingly productive; but then they spread upon 

 the land all the dung they can procure, and not only station 

 children and old women on the highways, with little baskets 

 to collect this manure as it falls from horses or from mules, 

 but like the farmers in the south of France they pick the. 

 leaves from the trees in autumn, and this at a considerable 

 expense. Of such importance do they consider vegetable 

 matter as the food of plants. 



It must be confessed, that we have frequently occasion to Plants affect 

 observe plants dependant on the nature of the earth in which l )CC " ,,ar 



curt } is * 



they are found, and affecting each its peculiar earth, in 

 which they grow spontaneously and thrive. 



Thus on chalky and calcareous soils we find thesium lino- as chalk; 

 phyllum, anlhyllis vulneraria, asperula cynanchia, lotus cor- 

 niculatus, hippocrepis comosa, poa cristata; and three of the 

 sedums, the*, acre, s. album, and s. reflexum; as on the 

 Wiltshire downs and on the hills round Bath. 



On sand we see arenaria, rumex acetosella, and all the sand; 

 sorrels ; the plantago maritima, the plantago coronopus, the 

 onopordum acaiithium, the sedum anglicum, and most re- 

 markably the spartium scoparium. 



On clay, if wet, the carices, thejunci, schoemts, aira ces- wet day ; 

 pitosa, and aira cccrulea, orchis latifolia, and orchis conopsea ; 

 if dry, the primula veris, orchis mas, orchis maculata, and dry day; 

 poa pratensis. 



On bogs, the equiseta, vaccinium uliginosum, anagallis te- bogs; 



nella, sctrpus palustris, menyaiithes trifoliata, and droscra 



delight to dwell. 



On the sea-shore, and wherever the muriatic salt abounds, ,, 



. . * or tne | | 



as near Alicant m Spain, we find salicomia Europcea, four shore. 



species 



