VIII INTRODUCTION, 
modifications, work on the principle of retaining the 
superfluous rainfall till the earth is at leisure to 
absorb it, but there is a weak point in this way of 
dealing with the heavy rains of Ceylon. No one 
has ever made holes big enough, or embankments 
strong enough, to meet; the requirements of the case. 
All precautions may be taken with satisfactory results 
for a long time; yet the day comes, when all is of 
no avail: embankments give way, holes overflow, the 
water gathers body and force, and rushes down the 
hill sweeping away every obstacle, leaving a deep 
trench behind it, down to the subsoil, and often far 
into it, all which may be the spoil of a few minutes, 
and thus the work and watching of years may be 
neutralized in an hour. 
If I could retain the superfluous rainfall of one 
Season so as to apply it to the deficiency of another, 
1t would in some districts be a paying operation to 
secure that end at a considerable cost; but retaining 
the water on the surface till the land can absorb 
it is not the way to accomplish this, nor do I know 
of any plan within the limited expenditure of a paying 
cultivation, by which it can be done. The water 
that passes through the soil occupied by the roots 
of my plant, and sinks beyond them, may feed 
springs at a lower elevation, butit is of no service to 
my plant. Were there a definite quantity of ammonia, 
in all the rain that fell, and were that quantity 
proved of sufficient value to justify expensive works 
for retaining it in the land, good and well, but all 
that we know on this subject is, that there is more 
or less ammonia contained ina thunder shower that 
falls after a period of dry weather, whea the soil is 
most absorbent; but that in the great bulk of the rain 
that falls in the course of the year there is hardly 
a trace of nitrogenous matter. I cannot therefore 
see any advantage to my cultivated plant in retain- 
ing more of the rainfall on my land than the soil 
naturally absorbs during the fall, and as I observe 
that the period of thorough saturation is not one of 
growth, but of compelled rest to the plant, I see it 
to be my business to convey the superfluous water, 
as quickly and with as little injury as possible, off 
