Superphosphate of Lime. 
155 
It should be observed, however, that in this experiment the 
land was probably more suited lor swedes than white turnips ; 
but, on the other hand, the lateness of the season was more unfa- 
vourable to the swedes, besides which the crop previous to the 
globes had been manured with stable-dung, whilst the other field 
had received no dressing since J 843. 
Supposing that these results are to be attributed to the greater 
suitability of the manure for swedes, and not owing to other 
causes, the result is certainly in keeping with the comparative 
analysis of the ashes of swedes and white turnips, which tells us 
that the former contains 408 lbs. of phosphoric acid, and the 
latter only 73 lbs. in 100,000 lbs. each. 
It must be evident from this circumstance that white turnips 
do not require so large a quantity of bones, whether vitriolized or 
not, and it also corresponds with the well-known facts that 
swedes require a larger quantity of dung to supply the necessary 
phosphoric acid, and also that white turnips on favourable land 
can be raised with ashes alone far more easily than swedes. 
I would therefore recommend in all cases with white turnips, 
that a less quantity of vitriolized bone be employed, and that 
guano, or some other manure possessing its properties, should 
be used in combination with it. 
In May last, a portion of land consisting of 1^ acre was drilled 
with Matson's green top globes, and manured with 1 bushel of 
sulphated bones, 1 cwt. of African guano, and about 25 bushels 
of turf-ashes per acre. The crop was a very good one, exceed- 
ing 20 tons to the acre. 
In several instances within my own knowledge where guano 
has been used with ashes, the crop has been destroyed by the 
pungency of the manure, probably owing to the ammonia which 
it contains. There is no danger of this taking place with vitriol-, 
ized bones, and I have found, though seeds will not vegetate if 
entirely surrounded with them, they readily will if the manure 
is mixed with twice its weight of mould. 
The last season has not been a favourable one for displaying 
the peculiar advantages of vitriolized bones, or rather, it has been 
from its wetness so favourable for common bones and every other 
description of manure, that an indifferent field of turnips has 
been the exception and not the rule. It is in a dry season when 
the fly is particularly rife and active, when crop after crop is de- 
stroyed by this entomological pest, that the advantages of ensur- 
ing a vigorous growth to young plants is properly appreciated. 
Amongst all the specifics or antidotes for the fly, there is none, I 
believe, equal to the employment of vitriolized bones. Hitherto 
I have not met with, or heard of, a single instance in which it 
has failed to force the plants out of the way of the fly. It is in a 
