374 APPENDIX E. 



In these solutions are contained in grammes,- 



With the exception of the mixture used in Period V., there 

 •was added to the others also 0-1 gramme of phosphate of iron. 



The duration of these periods was accidental, depending on 

 fluctuating meteorological conditions of the atmosphere, but 

 was so far regulated that a distant period was marked whenever 

 almost exactly 1 litre of water had been exhaled through the 

 leaves of the plants. At this time the remainder of the liquid 

 was drawn off for analysis, and the vessel filled with a fresh 

 solution. 



In the following the results of the analysis are given along 

 ■with the chief periods and circumstances of the experiments. 

 In the analytical results in column a, is placed the total quantity 

 of each acid, and salt received by the plant in that particular 

 period ; in column b, the bases and acids found by analysis in 

 the remainder of the fluid ; in column c, the difference between 

 A and B, indicating the quantity of bases and acids absorbed by 

 the plants. Further, the relations of the bases to each other, 

 and that of magnesia to sulphuric acid (calculated from column 

 a), are given; the quotients also express the proportions in 

 which these matters were given to the plants at the begin- 

 ning of the period. Immediately underneath, indicated by 

 ' absorbed,' are placed the same proportions, calculated from 

 column c, in order to show in what ratio the plant has selected 

 these matters (when there does exist a determinate power of 

 selection). 



