has tried the method by ammoniacal fumes with 
success ; but more extensive trials are necessary 
to establish its general efficacy. It may, however, 
be safely adopted, for if it should fail in destroy- 
ing the fly, it will at least be an useful manure to 
the land. 
After the roots and leaves of the infant plant 
are formed, the cells and tubes throughout its 
structure become filled with fluid, which is usually 
supplied from the soil, and the function of nourish- 
ment is performed by the action of its organs upon 
about four bushels to an acre, to pass out, and to fall into the 
drills with the turnip seeds. Whether it was by affording highly 
stimulating food to the plant, or giving some flavour which, the 
flies did not like, I cannot tell ; but in the year 1811, the adjoin- 
ing rows were eaten away, and those to which the composition 
was applied, as above described, were scarcely at all touched. 
It is my intention in future to drill my crop in, first, with the 
composition on the top of the ridge ; and then to sow at least a 
pound of seed, broad-cast, over the whole ground. The expense 
of this will be very trifling, not more than 2s. per acre ; and 
the horse-hoe will instantly sweep away all the supernumeraries 
between the rows, should those escape the flies, to which however 
they will be chiefly attracted ; because it will always be found 
that those insects prefer turnips growing in poor, to those in 
rich ground. One advantage seems to be the acceleration given 
to the growth of the plants, by the highly stimulative effects of 
the food they instantly receive as soon as their growth com- 
mences, and long before their radicles have reached the dung. 
The directions above given apply only to turnips sowed upon 
ridges, with the manure immediately under them; and I am quite 
certain, that in all soils turnips should be thus cultivated. The 
close vicinity of the manure, and the consequent short time 
required to carry the food into the leaf, and return the organ- 
izable matter to the roots, are, in my hypothesis, points of 
vast importance ; and the results in practice are corre- 
spondent.” 
