BOOTS AKD THEIR FTTNOTIOITS. 43 



and will take up whatever calcareous substances (lime 

 and its compounds) the water of the soil contains." 



Prof. J. H. Balfour, in his "Manual of Botany," says : 

 " Gaseous matters are taken up by the roots of plants 

 and circulated along with the sap, as well as in the spiral 

 vessels. These usually consist of common air, carbonic 

 acid, and oxygen." And further, he thinks that the dif- 

 ferences in the absorption of solutions depend on the 

 "relative densities alone, and not on any peculiar extract- 

 ing power of the roots, for it is well known that poison- 

 ous matters are absorbed as well as those that are whole- 

 some." On the contrary, another English authority. Dr. 

 MaxweU T. Masters, in his recent work, "Plant Life," 

 says : "It is a moot point whether any carbon is taken 

 up by the roots, but if any, it is only a small proportion." 

 But Dr. J. M. Schleiden ("Principles of Scientific Bot- 

 any " ), in referring to this same mooted point, says : 

 "The most universally distributed medium of solution 

 in nature — water — ^is also the fluid which is absorbed by 

 the plant cell, and conveys all other matters into its in- 

 terior. The most essential of these matters are carbonic 

 acid and ammonia, both of which are contained in water 

 which either falls from the air or has been a long time in 

 contact with it. Water, carbonic acid and ammonia 

 contain carbon, hydrogen, oxygen and nitrogen, all of 

 which are essential to the formation of the assimilated 

 substances, and to the especial nourishment of the cell. 

 But water occasionally conveys to the cell, in small quan- 

 tities, all substances which are capable of solution in 

 water." 



Of the many other works of equally celebrated author- 

 ities examined on this point, no two fully agree in their 

 "opinions," for we can scarcely bestow upon the infor- 

 mation derived from such sources so dignified a name 

 as "knowledge." But we may safely credit roots with 

 the faculty of modifying and changing certain elements 



