VARIATIONS IN MINERAL COMPOSITION OF SAP, 

 LEAVES, AND STEMS OF THE WILD-GRAPE VINE 

 AND SUGAR-MAPLE TREE 



By O. M. Shedd, ' 

 Chemist, Kentucky Agricultural Experiment Station 



INTRODUCTION 



In a previous publication Kastle and the writer (9)^ have shown the 

 relation existing between the mineral components of the sap of the wild- 

 grape vine (Vitis cordifolia) and those contained in the young leaves and 

 stems at a certain period in its growth during the same year. At that 

 time these writers stated that they did not know whether these relations 

 would hold true throughout the growing season, and they purposed to 

 continue the investigation so as to include the sap and other materials 

 from different portions of this vine and other plants. 



Since our former publication, the writer has found in the literature at 

 hand that considerable work has been done by Chandler (i), Harris and 

 Gortner (8), Dixon and others (2, 3, 4, 5, 6, 7) on the physiochemical 

 properties of certain saps or plant juices, but, so far as we have been able 

 to find, no work has been done on the mineral composition of the sap or 

 on the changes occurring therein which might have any bearing on the 

 above-mentioned investigation. 



EXPERIMENTS WITH WILD-GRAPE VINE 



With this idea in view, the writer has during the last three years 

 (1912-1914) collected samples of the sap from the vine employed in the 

 former work, in order to determine (i) whether the mineral composition 

 of this sap varies at the same time in different parts of the vine, (2) 

 whether it varies during a single season at a certain point, and (3) whether 

 it varies during different years. The analyses are of interest, inasmuch 

 as they show large differences in the composition of the sap, depending 

 on the time and place of collection. The results are given in Tables I to 

 XI and are expressed in percentage by weight, except where otherwise 

 stated. The mineral components of the original sample have been cal- 

 culated from the amounts found in the ash, except the chlorin, which 

 was determined in the fresh sap. The sulphur-trioxid content of the 

 original substance is probably low, since more or less sulphur is lost in 

 ashing organic materials. 



^ The author desires to express his gratitude to Dr. J. H. Kastle, Director of the Kentucky Experiment 

 Station, for his helpful advice during the progress of this investigation. 

 ^ Reference is made by number to " Literature cited," p. 541-542- 



Journal of Agriculture Research, Vol. V, No. 12 



Dept. of Agriculture, Washington, D. C. Dec. 20, 191s 



bh Ky. -3 



(529) 



