166 Mr. E. H. Acton. The Assimilation of Carbon 



The ethyl ethereal salt was saponified, and the barium salt obtained. 

 From the barium salt the pure acid was obtained by decomposing 

 with dilute H a S0 4 * 



The calcium salt used in No. 6, II, A. and B. was obtained by- 

 neutralising a portion of the pure free acid with Ca(OH) 2 . 



Experiments with " LaBvulinic Acid." 

 A. With Cut Branches. 



Solution used. 



Plants. 



Results. 



The culture solution 

 + 1 per cent, lee- 

 vulinic acid 



Ranunculus acris 

 Alisma plant ago 

 Scrophularia aquatica 



No starch formed (5 

 days) ; not apparently 

 injured. 



B. Solution supplied to the Roots, 



Same solution as 

 above 



Phaseolus vulgaris 

 CheirantJius Cheiri 

 Quercus robur (3 plants) 



No starch formed (8 

 days). 



Plants all recovered normal growth on planting out, and had formed starch 



after 3 to 4 days. 





C. Solution placed on Leaves. 



Same solution as 

 above 



Acer pseudoplatanus (with 

 roots in culture solution), 2 

 plants 



No starch formed (5 

 days). Leaves not ap- 

 parently injured where 

 solution had been ap- 

 plied. 



* Leevulinic acid obtained as described from leevulose or cane-sugar has been 

 shown by Conrad (' Liebig's Annalen,' voL 188, 1877) to be identical with /3-acetyl- 

 propionic acid /acetyl-propionic acid = CH 3 — CO 



CH 2 

 I 



CH 2 

 I 



COOH) 



obtained by the action of baryta-water on diethyl acetosuccinate. Leevulinic acid 

 is therefore one of the " ketonio acids," which have been so largely used in recent 

 chemical synthesis, and the non-formation of starch by the plants from this source 

 I regard as particularly interesting. 



It was my intention at the beginning of these experiments to try the calcium or 

 magnesium salts of " aceto-acetic " acid and " acetyl-phenyl-propionic acid," as 

 also some of the substituted " malonic ethers" of the form R.B/.C.(CO.C 2 II 5 ) 2 

 (R.R'. = alcohol radicles), all of which are powerful reagents in organic synthesis, 

 but, finding the results negative with lsevulinic acid, I conclude that they would 

 probably not be different with the above-mentioned bodies. 



