534 
Journal of Agricultural Research 
Vol. V, No. 12 
Table VIII .—Percentage composition of ash of samples in Table VII 
Constituent. 
Sample 
No. 285. 
Sample 
No. 812. 
Sample 
No. 852. 
Sample 
No. 900. 
Ratio 
between 
minimum 
and maxi¬ 
mum. 
Silica (Si 0 2 ). 
Ferric and aluminic oxids (Fe 2 0 3 + 
A1 2 0 3 ). 
O. 405 
• 540 
19. 49 ° 
3.900 
1. 500 
41. 380 
5. 090 
4 - 590 
0. 809 
• 387 
36. 070 
7 * 594 
2. 742 
19. 617 
3 - 059 
2. 742 
0.339 
. 261 
41. 628 
6. 364 
3 - 234 
13. 146 
3. 860 
5.008 
0.485 
• 143 
33 - 432 
5.828 
1.483 
23. 787 
4-349 
3 - 562 
1 : 2. 39 
1 :3. 78 
i : 2. 14 
1 : 1. 95 
1 : 2.16 
1 : 3 - IS 
1 : 1. 66 
1 : 1. 83 
Calcium oxid (CaO). 
Magnesium oxid (MgO). 
Sodium oxid (NaaO).. 
Potassium oxid (K 2 0 ). 
Phosphorus pentoxid (P 2 0 6 ). 
Sulphur trioxid (S 0 3 ). 
Cflrnnn dirvxid. not d^t^rmined . 
Total . 
76.895 
73. 020 
73 - 840 
73.069 
As stated before, Nos. 285, 812, and 852 were collected from the same 
branch, whereas No. 900 was taken an equal distance from the root on 
another branch, as the former was so greatly weakened that no sap 
exuded from it at the proper time, although new growth came on it later, 
showing that it was not dead. If a comparison now be made of Nos. 285, 
812, and 852, it will be found that there has been a marked reduction in 
practically all of the mineral substances in the sap in the two succeeding 
years compared with the first, and, moreover, this was very sharp in 
some constituents in the second and, in others, in the third year. Fur¬ 
thermore, it will be noticed that among those which show a decided 
decrease in the second year are potassium and phosphorus, both of which 
are included among the chief essential plant-food elements. 
According to the different analyses of the sap, potassium is among 
the high mineral constituents, and as this element has shown the largest 
loss, this may account for the weakened condition of the branch. 
The ratios of calcium oxid to magnesium oxid and of potassium oxid 
to sodium oxid in the various samples of Table VII are as given in Table 
IX. 
Table IX .—Comparison of ratios of calcium oxid to magnesium oxid and potassium oxid 
to sodium oxid in sap of wild grape from the same point on the vine at the beginning of 
the sap flow during four successive years 
Sample No. 
Ratio of 
calcium 
oxid to 
magne¬ 
sium oxid. 
Ratio of 
potassium 
oxid to 
sodium 
oxid. 
5.0 : 1 
27 * 5 : 1 
7. 0 : 1 
4. 8 : 1 
6. 7 : 1 
8C2 . 
4. 2 : 1 
16. 7 : 1 
5*7 : 1 
