120 



Mr. E. H. Acton. The Assimilation of [May 16*. 



The shoots or plants in this liquid were placed under a bell- jar, so 

 arranged as to exclude all possibility of entry of C0 2 from surround- 

 ing air during the experiments, but to allow a free circulation 

 between the air in bell-jar and external atmosphere : this is effected 

 by tubes introduced through the india-rubber stopper of bell- jar com- 

 municating with the outside through soda-lime U" tnoes - Several 

 capsules of soda-lime and cylinders of strong KOH solution were 

 placed under the bell-jar to absorb any C0 2 given off by respiration. 



In No. 2, special precautions were taken to prevent any C0 2 

 evolved from roots finding its way to the leaves. 



In No. 3, the same result was obtained by the addition of barium 

 acetate to the solution in which the plants were immersed. The 

 apparatus was less complex in this case. 



In all the experimeuts, provision was made that the air in confined 

 spaces mig'ht be in free communication with external atmosphere (to 

 admit free supply of oxygen), but always by passage through soda- 

 lime U- tu ^ es - 



The plants used were not selected for any particular reasons beyond 

 the fact that a good supply of them was conveniently at hand during 

 the progress of these experiments. They were for No. 1, shoots (cut 

 branches) — 



Acer pseudo-platamis, L. 

 Manuncidtis acris, L. 

 Tilia Europcea, L. 

 Alisma plantago, L. 



Phaseolus vulgaris, L. 

 Cheiranthus cheiri, L. 

 Scrophularia aguatica-, L. 



For (No. 2) whole plants, seedling plants of — 



Acer pseudo -plat anus, L. 

 Phaseolus multiflorus, L. 

 Qiiercus robur, L. 

 Euphorbia helioscopia, L. 



For (No. 3) water-plants, shoots of- 



Anacharis alsinastrum, Bab. 

 Sparganium natans, Bab. 

 Chara vulgaris, L. 



Phaseolus vulgaris, L. 

 Cheiranthus cheiri, L. 

 Campanula glomerata, L. 

 Epilobium hirsutum, L. 



Callitriche aguatica, Sm. 

 Fontinalis antipyretica, L. 



The substances (carbon compounds) used in all cases (1) and (2) 

 in some cases also (3) were acrolein, acrolein-ammonia, acrolein com- 

 pound with acid sodium sulphite (NaHS0 3 .C 3 H 4 0), allyl alcohol, 

 glucose (partly quantitative), acetic aldehyde, aldehyde (acetic) 

 ammonia, glycerin, la3vulinic acid, calcium lsevulinate, saccharon (cane- 

 sugar, partly quantitative), inulin,* dextrins, soluble starch, glycogen, 



# The inulin was free from glucoses, but it is doubtful whether it was really 

 pure. 



