EXPERIMENTS ON VEGETATION IN SOLUTIONS. 371) 



Present Not Present 



0-016 gramme potash Sulphuric acid (only indistinct opalcs- 



O-OOS „ limo coneo with chloride of barium). 



001 „ phosphoric acid Magnesia. 



Iron and silicic acid. 



From the circumstance that in this solution there was no 

 silicic acid, it is plain that the glass vessel had furnished none 

 to the fluid by decomposition in the course of one to two weeks. 



VII. Period. From August 16 to September 4,— 



Weight of plant on 16 August . . . 280 grammes 



„ „ 22 „ at 9 o'clock a.m. 316 „ 



22 „ „ 9 „ p.m. 320 



28 „ „ 9 „ „ 330 



1 Sept. „ 9 „ „ 327 



4 „ „ 9 „ „ 317 



From September 1 the weight diminished by the drying of 

 the leaves, and as this decrease was accidental, the plant was 

 not thencefoi-ward weighed. The leaves shrivelled. The plant 

 had exhaled 3^- litres of water in the period. At this time it 

 was placed in a vessel containing 1 '5 litres of water, to deter- 

 mine what salts returned to the water by endosraone. The 

 water was kept up at the same level by daily additions, and at 

 last was allowed to exhale until the residue was 1 litre. In this 

 litre were found 0-031 carbonate of lime and 0-007 carbonate of 

 magnesia. Both salts were left in the basin undissolved after 

 evaporation, and after the residue had been treated with water. 



In the water with which the residue left on evaporation in 

 the basin had been extracted, the following substances were 

 found in solution : — 



0020 lime f together with organic matter which 



0'0006 phosphoric acid •> reduced a solution of oxide of copper 

 0'0034 potash Land potash. 



In this last solution not a trace of iron, sulphuric acid, or 

 magnesia, was found. As the preceding analyses indicate, the 

 solution of nutritive matters for gramineae must have the 

 following composition : — 



MgOSOg + 4CaON05+ 4KOXO5 + xKOPO, 

 (Compare 'Chem. Central Blatt, 1861,' s. 465, 564, and 945.) 



* At all periods the plants threw off organic substances, but cliitfly in the last 

 periods. 



