62 



INORGANIC CONSTITUENTS. 



In the preceding experiments, the solution contained only a single 

 substance. In those which follow, M. de Saussure dissolved in the 

 water two or three salts, a mixture of sugar and gum, &c., in order 

 to ascertain whether the plants would make any selection from mixed 

 solutions. 



In 25 fluid ounces of water two or three species of salt were dis- 

 solved, the weight of each species being nearly 10 grains troy. 

 Each ounce of water would therefore contain either iths or '^ths of 

 a grain of saline or soluble matter. As in the preceding experi- 

 ments, the plants were made to absorb precisely one half of the so- 

 lutions. Analysis pointed out the quantity and the nature of the 

 substances which remained in the liquid not absorbed, and conse- 

 quently the salts which had penetrated the vegetable. 



In reducing this table, which exhibits the results obtained, the 

 weight of each particular salt in the solution is represented by lOO 

 parts. 



M. de Saussure confirmed these results in experimenting on the 

 common peppermint, {mentha piperita,) Scotch pine, and common 

 luniper. The substances absorbed in greatest proportion by the 

 polygonum and bident were also those that were taken up in largest 

 quantities by these plants. 



