21 



made up to loo cc. gave values shown in Table XVI. A trace only of 

 pentoses was found in the extract. 



Table XVT. — Sugar Determinations in Extracts. 



Cupric-r educing power. 

 Mg. CuO. 



Original. Clerget. Complete. 



398.0 1656.8 19336 



652.8 1873.6 1990.4 



The results are similar to those in Table XV. 



Examination was made for starch in carnation leaves taken from the 

 plant after a day of sunshine by boiling them for some time in alcohol, 

 then in water, and testing leaf sections with an alcoholic solution of iodine ; 

 starch was found to be plentiful. Comparative determinations of the 

 starch content* were made upon the residues from sugar extractions, using 

 a diastase solution prepared by extraction of ground malt with mono- 

 sodium phosphate solution at ice-box temperature, but not dialyzed.** 

 Fifty cubic centimeters of water were added to the residue and the starch 

 gelatinized by boiling for five minutes, with continuous stirring. After 

 cooling to 60°, 5 cc. of the diastase solution were added with a pipet and 

 digestion allowed to proceed for an hour. The mixture was again heated 

 to boiling and 5 cc. of diastase again added and after an hour the mixture 

 was filtered and washed thoroughly. The maltose in the filtrate was 

 hydrolyzed to glucose by the modified Sachsse method and glucose deter- 

 mined with Fehling's solution, correction being made for maltose in the 

 diastase solution. The values obtained for samples from sets of 2-10-15 

 and 2-1 7-1 5 are shown in Table XVII. 



Table XVII. — Starch Content of Carnation Leaves. 



Starch per cent. 

 Treatment. 2-10-15. 2-17-15. 



check 2.72 3-44 



K 1.94 3.09 



A lower starch content in "check" tissue is indicated by the results. 

 While these analyses were not made over a long enough period to form 

 a basis for a conception of the effect produced by potash upon carbohydrate 

 production and transformations, the higher sugar with lower starch 

 content is interesting in view of the work of Sherman and Thomas^^ upon 

 the activating action of potassium sulfate upon diastase. 



Summary. 



The purpose of the investigation was to determine the effects upon the 

 plants of large applications of certain commercial fertilizers to the soil 

 on which carnations were grown. 



* Brown and Morris* state that preliminary washing with cold water as in the 

 O'Sullivan method, is unnecessary in Tropaeolum majus. 



** Sherman and Schlesinger, /. Am. Chem. Soc, 25, 1619 (1913). 



