126 
end of the rainy period, when the rainfalls became less frequent, the 
percentage rose to nearly its former value. On the other hand there 
was a regular diminution of the other elements that were not sugar, 
and consequently an improvement in the percentage of purity. There- 
fore a permanent injurious influence of the heavy rainfall on the 
quality of the beet was not proven. 
| | Percentage Per 
|» @e= _ cent- 
| eo. |= = —$— | age 
Zz Date of measures. | 1 Dee . ee pe geal 
days. |Sugar. | a eat Bal ib 
sugar 
September 20 (before rain). ___._. LIA Aah BG Sa 0) 118.13 |" “3.273 30s0)) meee 
September2/((alter rain) =- === 8: oss sas ote eee 6} 12.35.) 3.15) 79.6) 25.4 
October 9\(atterrain) =. 5-222. ese ee ee ee eee 9| 12.56] 2.84 81.5 | 22.5 
October/20\(alterrain)) 1. =e eee ese eee eee 3| 13.04] 2.81] 82.3) 21.4 
Grassmann (1887) also confirms the results of Girard to the effect 
that the sugar once formed in the beet remains there, no matter what 
the further growth may be. There the diminution of the percentage 
of sugar after a rainfall is only relative in that the sugar is dissolved 
in more sap, and this is distributed throughout a greater mass of beet; 
the sugar, and with it the percentage of purity, sinks only very lit- 
tle after the first rainy day, but on the second sinks more considera- 
bly and then slowly rises from the third to the fifth day. (See 
Wollny, X, p. 300.) 
REMARKS. 
Now that the previous studies have shown the importance in agri- 
culture of the quantity of available water the question still remains 
whether the results of these experiments are directly applicable to 
determining the influence of rainfall on vegetation under the natural 
climatic conditions. We could in advance answer this question in 
the negative, inasmuch as the precipitation is never so uniform as the 
water artificially supplied in these experiments, as also because the 
utilization of the natural rainfall by the earth varies with the physi- 
cal properties of the latter; but by a closer consideration one is led to 
the conclusion that in spite of the departure from natural conditions 
still the results of these experiments do allow us to draw many con- 
clusions as to the influence of rainfall on the growth of cultivated 
useful plants, especially when we leave out of consideration the effect 
of the water at different epochs of vegetation and the peculiarities of 
the capacity of the soil for water, and at first study only the average 
character of the climate as depending on the amount of precipitation 
and consider the weather during the growing season. 
