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decomposed very slowly, and therefore afforded to the plants 

 in a very weak solution ; but Saussure found that plants do 

 not suffer much hy weak solutions of poisonous matters, ^gain, 

 it seems very singular that the poison is only absorbed in the 

 winter months, when vegetation is languid, and that the clover 

 from this cause should not perish during the warm months, 

 — the period of its greatest growth. But the red and white 

 clovers are perennials : Smith, in his English Botany^ de- 

 scribes them as such. The red clover grows as a perennial 

 in the vale of Aylesbury and in the rich pastures of Lincoln- 

 shire ; and Mr. Baines, the editor of the Flora of Yorkshire, 

 says that it grows as a perennial near York. Now, if this 

 plant excretes in one year as much as will poison the soil 

 upon which it grows for ten or twelve years, how is the same 

 plant enabled to live continually in the midst of its own 

 accumulated excretions ? In fine, the conclusions of Macaire's 

 experiments have been disproved by Meyen and Unger. 

 They obtained excretions from those plants only whose roots 

 had been mutilated by their removal from the soil into water, 

 which is not their natural medium of growth ; but in employ- 

 ing water plants, and placing them in various solutions, they 

 could not detect by the most delicate re-agents, the rejection 

 of any of the absorbed agents.* 



But an anatomical and pathological examination of the 

 dying red clover plant, will prove that no poison received by 

 the roots is concerned in its death ; for plants which are 

 poisoned assume a very different appearance. 



During the last winter I took from different fields, and 

 particularly from the clover-sick portion of the before-named 

 field, a great number of dying plants, at different periods of 

 the winter, and examined them with the microscope ; slices of 

 whole stems and leaves were placed under a magnifying 

 power of 100 to 150 diameters. The part first injured is 



* See " Root," Penny Cyclopaedia. 



