14 H. A. SPOEHR 



in opposite directions. Thus far it has not been possible to dis- 

 cover conditions which favor only the synthetic action. In the 

 light from a quartz mercury vapor lamp, both the synthetic and 

 the decomposing actions are greater than in sunlight. It is an 

 interesting fact that the photolysis of this syrup yields, besides 

 formic acid, a volatile substance giving many of the tests for 

 aldehyde. All that can be said at this time, however, is that this 

 is not formaldehyde. 



Attention has already been called to the fact that the basis of 

 the Baeyer theory is the fact that the formaldehyde solutions are 

 condensed to sugars by means of alkalies. It is important to 

 consider the conditions under which this reaction takes place. 

 From the very extensive researches of Nef^^ it is certain that the 

 condensation of formaldehyde to sugar takes place only with 

 alkali hydroxides and at high temperatures. Is, therefore, this 

 reaction actually applicable to the plant? 



It is true that the heat energy necessary in the vitro reaction 

 might be obtained in the plant from the sunlight. But that the 

 necessary concentrations of alkali exist in the plant seems very 

 doubtful, and there is no evidence for assuming the presence of 

 some unknown enzyme which might take the place of the alkali 

 hydroxides. As to the action of the chloroplasts in this connec- 

 tion, we are equall}^ without evidence. It seemed therefore not 

 without interest to determine the action of sunlight on formal- 

 dehyde solutions in the presence of weak alkalies, such as might 

 possibly exist in the plant, and at ordinary temperatures. 



Three per cent formaldehyde solutions were used, with the salts 

 in tenth normal concentration. These solutions, in glass flasks, 

 were exposed directly to the sunlight. Calcium carbonate, po- 

 tassium bicarbonate, basic magnesium carbonate, zinc carbon- 

 ate, and potassium nitrate (which forms an alkaline solution 

 in the sunlight), ^^ after four months of insolation showed no trace 

 of sugar formation. Lead hydroxide, calcium hydroxide and 



'1 Nef, J. U., Dissociationsvorgiinge in der Zuckergruppe. Ann. d. Chem. 

 (Liebig) 403: 355, 1913. 



*■- Spoehr, H. A., The Relation between Photosynthesis of Carbon Dioxide and 

 Nitrate Reduction. Science 23: 63-4, 1911. 



