by Green Plants from certain Organic Compounds. 157 



The plants used for these experiments were — 

 Shoots (cut branches) of — 



Acer pseudoplatanus, L. ; Phaseolus vulgaris, L. ; Ranunculus acris, 

 L. ; Cheiranthus Cheiri, L. ; Tilia Europcea, L. ; Alisma plantago, L. ; 

 Scrophularia aquatica, L. 



Seedling plants (entire) of — 



Acer pseudoplatanus, L. ; Phaseolus vulgaris, L. ; Ph. multiflorus, L. ; 

 Cheiranthus Cheiri, L. ; Quercus robur, L. ; Campanula glomerata, L. ; 

 Euphorbia helioscopia, L. ; PJpilobium hirsutum, L. 



Water plants. — Shoots of — 



Anacharis alsinastrum, Bab. ; Callitriche aquatica, Sm. ; Fontinalis 

 antipyretica, L. ; Chara vulgaris, L. ; Sparganiu'm natans, Bab. 



The plants made use of in ^hese experiments were not selected for 

 any particular reason beyond the fact that I had an abundant supply 

 of them at hand in the ground behind St. John's College Laboratory, 

 where all these experiments were conducted. 



The seedling plants of Tilia, Acer, Cheiranthus, Campanula, 

 Euphorbia were all obtained from the place mentioned. Those of 

 Quercus were brought from a neighbouring field, and planted in the 

 garden in front of the laboratory. 



The young plants of Phaseolus multiflorus and P. vulgaris were 

 raised from seed in damp sawdust, and planted out till required for 

 use. 



The other plants were growing in the garden and immediate 

 vicinity. As I did not in any cases find the results differing with 

 the plants used where I considered the experiments had been satis- 

 factorily carried out, I selected those which seemed best adapted to 

 the apparatus in each case. 



The solution used for the culture of the plants, and referred to 

 throughout as the " culture solution," was prepared so as to contain 

 the weights given below in 100 c.c. of the liquid. 



Potassium nitrate (KN0 3 ) 0'15 grams. 



Magnesium chloride (MgCl 2 ) 0'10 ,, 



Calcium phosphate (Ca 3 (P0 4 ) 2 ). . . . 0*05 ,, 



Ferrous sulphate (FeS0 4 ) O025 „ 



Calcium sulphate (CaS0 4 ) 0'05 



Water (distilled) 100 



In the case of the water plants there was added to the above 

 3 — 4 per cent, of barium acetate (to remove C0 2 ), as mentioned in 

 describing the apparatus for water plants, which would cause some 

 alterations in the soluble salts. Soch a solution contains all the 

 elements necessary for normal growth of a plant except carbon. 



