BULLETIN OF THE BUSSEY INSTITUTION. 189 
The heaviest crops were the best in every sense, since they con- 
tained the largest and finest potatoes. The small crops were small 
potatoes. It is noteworthy that the field sloped slightly, in such 
wise that plots 1 to 5 were a little lower than the rest; though 
before the potatoes were dug, the lower land had been thought to 
be poorer than that of the other parts of the experimental field. 
The slope was insufficient to divert rain-water from the other plots ; 
and, as it happened, very little rain fell during the course of the 
experiments. For that matter, the drought of 1873 is said to have 
been rather worse at West Peabody than at the Bussey Farm. It 
would seem to be plain that in this case also, as well as in the exper- 
iments of Sections A and AA, the unmanured strip of land (No. 3) 
supplied to the potato crop all the food it could make use of under 
the conditions of this exceptionally dry summer. Since none of the 
manures applied to the other strips could do more than this, the 
various mixtures were necessarily useless as regards this particular 
crop. If the land in question could only have been moistened, the 
crop of 1873 would have been able to partake not only of the natural 
supplies of food, and that more readily than was possible under the 
adverse circumstances that actually obtained, but it would have used 
the added fertilizers also. 
Norte. — It will be remarked that in several instances, notably in the trials 
numbered 8, 9,10, 11, the more soluble saline fertilizers, although applied in very 
moderate doses, seem to have done distinct harm to the crops. I am inclined to 
believe that this hurtful influence depends upon the fact noticed by Lawes (“‘ Experi- 
mental Investigation into the Amount of Water given off by Plants during their 
Growth,” London, 1850, p. 10), and by Sachs (Die landwirthschaftlichen Versuchs- 
Stationen, 1859, 1, 203), who find that the absorption of water by the roots of plants 
and the exhalation of water by their leaves is interfered with and retarded by the 
presence of saline matters in the soil which surrounds the roots of the plants. It 
is, of course, readily conceivable that the retardation of the transpiration of water 
may be beneficial to the plant under certain conditions, as Sachs has urged. But, 
upon the other hand, it is to be remembered that the free movement of water 
into and from the plant is a process wellnigh essential to vegetable growth, and 
that the presence in the soil of matters that tend to check or hinder it may be 
highly prejudicial to the prosperity of any crop that is not amply supplied with 
water. In the experiments of Mr. Saltonstall, where the plants were exposed to 
hot, dry air at a time of severe drought, when the soil could supply only a small 
fraction of the moisture that was needed for their healthy growth, there is good 
reason to believe that the saline manures did harm by interfering with the natural 
movement of water in the plants. | 
