: 118 
maintaining a very constant state of moisture in each. with the 
following results: 
} \| 
Gone Harvest. Cone Harvest. 
2. | LO) | ———S | | stant |- 
| Tub. ny | | || Tub. = 
| eneet Straw. Grain. | cance Straw.| Grain. 
| P. et. | P. ct. | 
1 SO | 0 8.8 } 5 20 | 6.9 17 
2| 60 | 12.8 9.9 Ga) a0 3.0 3.3 
BF | 40 dee O52 Nas | 5 Orde |-2eseeee 
+} | 83] 8s 1 eee | 
| | \| } | 
The general result, therefore, was that the largest harvest is given 
by soil containing 40 per cent of its maximum capacity for water. 
The general appearance of the plants showed that those having too 
little water had a less intensive life and were suffering from lack of 
nourishment rather than from the want of pure water itself. 
Fittbogen (1873) conducted a series of experiments on twenty 
tubs in groups of four. The relative weights of his harvests of oats 
were as follows: 
i] 
| ; | Harvest. | , Harvest. 
Mois- |__ Mois- 
Tub. ture i | __ || Pub. ture | - 
’ | Straw. Grain. | : Straw.) Grain. 
Pct: (PACs | 
it 80-60 oti 6.0 4 30-20 Syl | 4.0 
2 60-40 | 6.9 5.8 5 20-10 OO ONG 
40-30 | 7.7 6.1 || | 
These figures show that for moistures varying between 30 and 80 
per cent there was very little difference in the harvest, while for 
drier soils the harvest was decidedly diminished; but it is notable 
that for the driest soil (No. 5) the grain ripened earliest of all. 
Haberlandt, in 1875, reports the results of experiments on three 
tubs sown with summer wheat. The quantity of water allowed to 
tub No. 1 was just sufficient to keep the wheat alive; the other quanti- 
ties, with the harvest, are given in the following table: 
P . : 
| | Num- | Equiv- Harvest. 
I Tub Quantity|ber wa-| alent | 
‘| water. | ter- rain- : ‘i 
| ings. fall. SERIE ISR 
3 | = . 
cc. mm, 
1 6,200 | 381 | 24.4 | 21.8 6.6 | 
| { 
2 | 14,400 | 36 | 56.6 | 20.4 | 16.4 | 
3 24, 800 31 97.5 41.6 | 31.6 | 
Whence it would seem that the limit of useful water had not yet 
been reached. 
