0« Rajie-dust, 
193 
A drill, with a double row of coulters, was exliibitcd at the 
Bristol Meeting of the Royal Agricultural Society, which would 
be extremely useful in such cases as this. 
A few ridges which we drilled in this manner look at the pre- 
sent time very well ; some Avhich were drilled in the common 
manner tvith rapc-dvst and eartJi look well. A few drilled with 
rape-dust alone, in immediate contact with the seed, are a failure, 
a large proportion of the seed being destroyed. 
As a manure, also, for potatoes, rape-dust is not infrequently 
used. Like tlie turnip, the potato extracts a great supply of food 
from the atmosphere. It contains, also, a larger share of nitrogen 
than the turnip. It requires, therefore, a ready supply of food, 
in order that its leaves may come into use as soon as possible ; 
and in this food there should be nitrogenous matter. Rape-dust, 
acting as we have already shown, and containing so large a pro- 
portion of nitroyen, appears adapted to supply its wants. But 
the potatoe also requires a lasting manure ; nitrogen is necessary 
in the latter stages of its growth, and rape-dust is not calculated 
to afford a long supply. For this reason it will be necessary to be 
liberal in the quantity used : not lkss than four quarters per acre 
should be applied. 
With this a mixture of a few bushels of gypsum would have a 
beneficial effect. It would prevent the too sudden escape of the 
ammonia (or nitrogen) of the manure, as it will be hereafter shown 
that it possesses the property of " fixing ' this gas in combination 
with one of its own component matters. It is most extensively 
used along with manure for the potato crop in America, and, 
according to the best authorities, with success. 
Although, then, we should be inclined to say to the farmer, use 
farm-yard manure for your potato crops, and rape-dust for your 
corn and turnips, there can be no doubt but that if the latter be 
applied liberally, in cases where farm-yard manure cannot be had, 
a remunerative return may be obtained. 
A case in point may be instanced upon the farm of Mr. Styan, 
of VVhixley, Avhere a very good crop grown with rape-dust maybe 
seen at the present time.* We are told by a person who has been 
* Since the above was written, I find that this crop has not yielded so 
well as was expected. The reason is very easily given — only 2 qrs. of 
rape-dust per acre were used, when, as we have shown above, not less 
than 4 qrs. per acre should be applied for potatoes. 
The supply of nitrogen, &c. required to perfect the produce, at the 
latter stage of the potato's growth, demands a lasting manure, as well as 
an active one; and if rape-dust had been used, it should have been much 
more liberally applied ; 2 qrs. of rape-dust per acre, value 21. 5s., was a 
poor equivalent to 20 tons of farm-yard manure per acre, value from 11. 
to 10 1. —The Author. 
VOL. IV. o 
