EXPERIMENTS ON VEGETATION IN SOLUTIONS. 355 



female flower appeared, which was surrounded with paper to pro- 

 tect it from dust. Ou August 16 the height of the plant was 

 l/l metre ; it did not grow any more. The fruit-bearing stalk 

 was, on August 16, already 2 decimetres long, and had below a 

 thickness of 4 centimetres. 



On August 16 the water was drawn off and analysed. 



Present. Not present. 



0'016 gramme potash. Sulphuric acid (only indistinct opales- 



0-008 " lime. cence with chloride of barium). 



O'OOl " 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 

 thenceforward 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 determine what 

 salts returned to the water by endosmone. 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 : 



0-020 lime I together with organic matter which 



0-0006 phosphoric acid-< reduced a solution of oxide of copper 

 0*0034 potash ( and potash. 



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

 nesia was found. As the preceding analyses indicate, the solution 

 of nutritive matters for grammes must have the following com- 

 position : 



MgOS0 3 + 4CaON0 5 + 4KONO 5 + xKOPO 5 

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



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

 last periods. 



