330 On the Failure of the Red Clover. 



acid, and chlorine, but not an absence of the three last, otherwise 

 thej would not grow at all. In fine, this single consideration 

 alone, that the clover flourishes luxuriantly during the warm and 

 growing months of the summer, when food of all kinds is required 

 and assimilated by the plant, but perishes in the colder months, 

 when vegetation is nearly dormant and scarcely any nourishment 

 required, must preclude the opinion that the want of food of any 

 description whatever is concerned in its destruction. 



Will an excretion, or rather the emission of excrementitious 

 matter, from the roots of clover, account for its disappearance? 

 for in this opinion Professor Liebig coincides with that of 

 Mr. Legard. But against such an agent being concerned, it 

 may be urged in the first place that there are certain light lands 

 which have been reclaimed only thirty years ago, and therefore 

 never have produced clover at any former period, but upon 

 which the crop always disappears in the winter. A farm near 

 Barnsdale Bar upon the magnesian limestone, several farms on 

 the south side of Darrington upon the same geological formation, 

 and certain portions of the Yorkshire Wolds, are in this pre- 

 dicament. No excrementitious matter therefore can destroy 

 the clovers on these farms, because they have never grown the 

 plant. Macaire Princep found that the leguminosae (to which 

 family the clovers belong) emitted gum and carbonate of lime. 

 But the gums are very soluble in water, and therefore would 

 be easily washed out of the soil ; and it seems very extra- 

 ordinary that in the heavier soils, consisting of loam and clay 

 of the new red sandstone, this gum trifolii should only remain 

 three years, while in the lighter soils of the magnesian limestone 

 eight years, but in the still more open and porous soils of the 

 chalk wolds it endures twelve years. In fact, this wonderful 

 substance, contrary to the known law of eremacausis, decomposes 

 more slowly in proportion to the porosity of the soil, and in those 

 containing the most calcareous matter. Again, if this excretion 

 can remain in the soil nearly twelve years, it must be decomposed 

 very slowly, and therefore afforded to the plants in a very weak 

 solution ; but Saussure found that plants do not suffer much by 

 weak solutions of poisonous matters. Again, it seems very sin- 

 gular 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 and the period of its greatest 

 growth. But the red and white clovers are perennials ; Smith, in 

 his ' English Botany,' describes them both as such. The red clover 

 (Trifolium pratense) grows as a perennial in the Vale of Ayles- 

 bury and in the rich pastures of Lincolnshire, 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 



