EXPERIMENTS OX VEGETATIOX IN SOLUTIONS. 373 



line solution on the growth of plants, were observed hy Knop 

 and Stobmann. 



In the following are communicated the experiments of 

 Knop and Stobmann on the vegetation of maize, in watery 

 solutions. 



I. — Experiments of Knop. 



Knop based his experiments with maize on the earlier obser- 

 vations which he had made on the vegetation of barley and 

 cresses (see 'Chem. Central Blatt,' 1861, s. 564). According to 

 these observations the graminete require for their growth nothing 

 more than a normal solution, which contains sulphate of mag- 

 nesia, nitrate of lime, and nitrate of potash, according to the 

 proportion MgOS03 + 2CaON05 + 2KON05, in which phosphate 

 of iron was suspended, and phosphate of potash as required was 

 dissolved. The normal solution A made according to the above 

 formula contained in grammes — 



0-4512 2-2560 2-7072 



In consequence of using the solution in a more dilute form 

 in the first period, in order to promote a better radication, 600 

 cubic centimetres of the above solution were employed at this 

 time ; at every other period, 500 cubic centimetres were measured 

 off, and to this last quantity the phosphate of potash was now 

 added in the proportion indicated. The mixture, therefore, had 

 the folloAving composition in the five periods. The potash 

 which was added as KOPO5, ^^^ ^^ KONO5, are given separately 

 and united with a bracket. 



Period 

 I. 12 cent. cub. solution of KOPO;;,* 600 cent. cub. noiroal solution A 

 IL 10 „ „ 600 „ 



IIL & IV. 20 „ „ 600 



V. 30 „ „ 500 



cub. of the solution contained exactly 1 decigramme of KOPO5 



