1864.] CHEMISTRY OP MANURES. 197 



devised and extensively-varied series of experiments, lie determined 

 the comparative amount of this absorptive power possessed by 

 aeveral varieties of soil, whether natural, or artificially composed. 

 These he tried, both in their raw state, and burned, as also under 

 ordinary and extraordinary conditions of compression, comminu- 

 tion, &c., testing each with solutions of the alkalies and alkaline 

 earths, sometimes caustic, sometimes carbonated, sometimes in 

 combination with the strong mineral acids. By these experiments 

 he confirmed and extended partial observations of like kind 

 recorded long ago by Lord Bacon and Dr. Hales, as also a number 

 of analogous facts, experimentally ascertained by Berzelius and 

 Matteucci abroad, and by 3Ir. Huxtable and Mr. H. S. Thomp- 

 son in this country. Referring the reader for details to Way's * 

 original papers on the subject, the reporter may simply state here 

 that Way attributes this power to the peculiar properties of the 

 aluminiferous double silicates, which he states to be more abun- 

 dant in soils in proportion as these possess higher absorptive 

 power. This interpretation of the observed phenomanon has not 

 met with universal acceptance ; many, with Liebig at their head, 

 denying the proportionality alleged by Way, and seeing in the 

 absorptive power of soils for salts dissolved in water, only another 

 aspect of the physico-chemical surface-action due to their 

 porosity, and enabling them to absorb gases and vapors from 

 their diffusion or solution in the atmosphere. The reporter, 

 for his own part, rather inclines to the latter view. 



But the facts investigated by Way, independently 6f their 

 physical conditions and theoretical interpretation, possess an 

 importance and a generality which entitle them to rank among 

 the most conspicuous contributions to modern agricultural science.. 

 They prove, among other things, that the plant-food arrested by 

 the soil can be delivered only to the spongioles in immediate 

 contact therewith : and that, consequently, these can obtain fresh 

 food only under one of two conditions; — (a) when, by the grow- 

 ing of the rootlets, they are pushed forward into contact wdth fresh 

 portions of the mould ; (6) when the descent of rain through the 

 soil effects the solution of fresh saline matter, and calls again into 

 play the surface-attraction of the pores, so as to replenish those 

 previously exhausted by the contiguous spongioles. Showers 



* Rojal Agric. Soc. Journ. 1850-52-55. 



