10 
Research Bulletin No. 3 
plant with three large leaves was grown under similar condi- 
tions but in a soil of vegetable mold. Sachs had expected a more 
favorable outcome in the latter experiment on account of the 
greater hygroscopicity of the soil used but the results were simi- 
lar to those in the first. 
Mayer 1 in 1871, altho questioning the correctness of the cal- 
culations which showed a transpiration exceeding the precipita- 
tion, accepted the old view. "The absorptive power of the soil 
for water * * * is under all circumstances a useful soil 
property, as it becomes active only when there is an actual 
scarcity of water in the soil and so acts as a regulator." "The 
water thus condensed in porous solid bodies conducts itself ex- 
actly like other capillary held water and can, for example, 
when a field soil has in this way condensed water, be taken up 
by a plant's roots just like that which has entered the small in- 
terstices of the soil from the rain or by watering." 
RECOGNITION OF THE FALSITY OF THE OLDER VIEW. 
Wilhelm, 2 was as early as 1861 inclined to conclude from 
his experiments that the absorptive power of the soil was useless. 
Reisler, 3 according to Hilgard, began, in 1868, the experi- 
mental testing of the reality of the accepted importance of the 
absorptive power of the soil for the development of plants. 
Mayer 4 in 1875 reported experiments similar to those of 
Sachs, using peas, barley, and buckwheat in flowerpots filled with 
sand, garden soils, marl, and sawdust, the last as representative 
of very hygroscopic soils. In the case of each he determined 
both the water content at the time of the collapse of the plant 
and the hygroscopicity by Schtibler's method. He concluded that 
the power of condensation of the soil does not benefit the plants, 
as these have already been injured beyond recovery before the 
soil is able to absorb moisture from the air, and that the trans- 
piration of plants in the field had been greatly overestimated, 
there being no proof of an actual deficit of water. He recog- 
nized that the water remaining in the soil on the wilting 
of a plant was closely related to the maximum amount of 
1 Mayer, Adolph. Agrikulturchemie, First Edition, 1871, Part II, p. 
130. The writer is responsible for the translation. 
2 Wilhelm, G. Der Boden und das Wasser, 1861, Vienna, as reviewed 
in Hoffmann's Jahresberichte iiber die Fortschritte der Agrikulturchemie, 
vol. 5, 1862-1863, p. 18. 
3 Hilgard, E. W. Ueber die Bedeutung der hygroskopischen Boden- 
feuchtigkeit fur die Vegetation. Forschungen auf dem Gebiete der Agri- 
kulturphysik, vol. 8, 1885, p. 93. 
4 Mayer, Adolph. Studien iiber die Wasserverdichtung in der Acker- 
erde. Fruhling's neue landwirthschaftliche Zeitung, vol. 24, 1875, pp. 87- 
97, as abstracted in Biedermann's Centralblatt fur Agrikulturchemie, vol. 
11, 1877, pp. 243-249. 
