Stoedes raised tipon barren Land ivith artificial Manure. 357 
23 lbs. of silica, as well as a certain proportion of organic matters 
in the form of ammonia and carbonic acid. It was expected that 
if these were sufficiently supplied to the plant in its early stages, 
the remainder of the carbonic acid and ammonia necessary to the 
perfect swede would be furnished, whether, as Mulder affirms, 
from the decaying matter in the soil (especially the sawdust men- 
tioned afterwards), or from the ammonia brought down by the 
rains according to Liebig. The quantities of inorganic substances 
above enumerated are not constant, but vary, as is well known, 
within certain limits, according to the soil : they must be con- 
sidered as only an approximation to the quantities and proportions 
required. 
Now as potash and soda may to a great extent replace each 
other, I calculated that 30 bushels of woodashes would give those 
alkalis in sufficient measure. I made no provision for the alkaline 
earths, for the chalk soil would plainly yield lime enough; to this 
1 trusted to replace the minute dose of magnesia demanded. The 
phosphoric and sulphuric acids would be found amply in the 
2 cwt. of Ichaboe guano, 50 lbs. of burnt bones treated with 
25 lbs. of sulphuric acid in addition to the sulphates and phos- 
phates contained in the woodashes. The guano would also yield 
sufficient ammonia to the youmj swede-plant ; whilst two pot- 
load of sawdust already in a rotten state, having been fermented 
by pigs' manure and salt, would give out a constant supply of 
carbonic, as well as conduce, according to Mulder, to the constant 
formation of ammonia in the soil. The great affinity of decaying 
sawdust for moisture would prevent the effects of drought so for- 
midable to turnips on our higti chalk-lands. The opposite 
danger of excessive rains washing the manure away from the 
growing plants was guarded against by pouring over the guano 
and ashes employed 10 lbs. of sulphuric acid in a diluted form, 
thereby converting the highly soluble carbonates into the com- 
paratively insoluble sulphates of ammonia and potash. 
In order that every portion of the manure thus calculated 
might, as far as possible, be duly apportioned to each plant, it 
was determined to bury both the seed and manure in holes at 
measured distances; but the looseness of the soil, filling up each 
hole as soon as made, defeated this expedient. The labourers 
were then instructed to begin at the highest point, and working 
down hill to strike out with their hoes small drills 2 feet apart. 
The manure having been previously hauled to the summit, a 
large wheelbarrow, loaded with a sufficient quantity for two 
drills, was wheeled down the interval between the two drills ; and 
a handful of the contents placed at distances of one foot in each 
drill. Children followed dropping upon each deposit of manure 
three fingers-full of seed mixed with fine soil, which served to 
prevent the manure from burning the seed. In descending the 
