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water, with tabulated results. The extreme tenacity with which the 

 best cotton soils retain a very large proportion of their water of satura- 

 tion after lengthened periods of exposure to dry air is remarkable, 

 and the importance of this in the hot climate of cotton-culture 

 is pointed out. In immediate connexion with this point, their per- 

 meability, or the rate at which water percolates through these various 

 soils was ascertained, the relations of which to partial rain or dews, 

 and to the desiccation of one mass and species of land in times of 

 drought by others adjoining are important and obvious; and again, 

 in the same relations, the capillarity, or rate at which water is 

 drawn through and upwards in the soils from deep moisture below, 

 was determined. In this part of his labours the author considers 

 with some exactness the nature and measures of the true capillary 

 power of soils, refers to the recent interesting researches of Jamin on 

 the capillarity of porous bodies, and describes some new and peculiar 

 apparatus by which he has determined this for the soils in question, 

 the results being given in several tables. These indicate strikingly 

 one of the remarkable properties due to the extremely fine state of 

 division of these "best cotton soils," on which, in part, their fertility 

 depends, viz. that they draw up moisture from the subsoil with im- 

 mense power, and therefore from great depths, but yet do so with 

 great slowness ; so that in a torrid climate the subsuperficial supply 

 of water fluctuates but little, and is slowly supplied and long in 

 being exhausted in drought ; while other soils pump it up rapidly, 

 and as rapidly waste it. This property becomes more important 

 as the distribution of rain, both in season and in space, is more un- 

 equal naturally. 



The hygroscopic power, or power of absorbing aqueous vapour 

 from the atmosphere, is next experimented upon, arid the results are 

 tabulated, and also represented graphically by curves, as are several 

 of the other numerical results. 



The author then proceeds to the highly important subject of the 

 absorptive power of the soils for gases directly or indirectly affecting 

 the growth of plants. 



Tabulating the results for oxygen, carbonic acid, and ammonia, 

 the most striking result here exhibited is the prodigious power of 

 absorbing ammonia possessed by the dry canebrake soils. This 

 soil condenses 52 volumes (equal to its own) of ammonia, and its 



