Phospliatic Manures for Root-Crops. 
59 
applied with the liquid-drill as 4 cwts. or more of the same manure 
applied drv. 
The application of superphosphate bv the liquid manure drill 
certainly must be regarded as practically the most economical, 
and philosophically as the most rational, mode of incorporating 
this turnip-manure with the land. 
In the beginning of this paper I expressed the opinion that 
superphosphate mav occasionally be ineffectiye as a turnip- 
manure, because the soils to which it is applied ma}- contain a 
sufficient proportion of phosphates to meet all the requirements 
of the turnip-crop. 
Seyeral striking: instances which have been brousrht under mv 
notice haye shown me that this is indeed the case. In the 
neighbourhood of Swindon, I am informed by Mr. Stratton that 
neither superphosphate nor bone-dust has much, if any, effect on 
the crops to which it is applied. 
Again, in the neighbourhood of Ilchester, I met with an 
unquestionable instance of a soil on which superphosphate, as 
well as other purely phosphatic manures, had no effect whateyer 
on roots. 
I haye heard of many other such localities, and haye no doubt 
that there are soils in other counties besides Wilts and Somerset- 
shire on which this class of fertilizers has no effect on root-crops 
nor on pasture land. 
I haye exatnined the soil from the neighbourhood of Ilchester. 
It is a soil resting on the lower chalk, or rather the junction of 
the lower chalk and greensand formation, and contains a great 
tleal more phosphoric acid than is usually found in most fertile 
soils. 
It is likewise an interesting fact that in the neighbourhood of 
Swindon, where I am informed phosphatic manures are of no 
use, coprolitic nodules haye been found. I liaye in my posses- 
sion specimens of phosphatic nodules from the neighbourhood of 
Swindon, and highly phosphatic marls from other parts of 
\\ iltshire. If in other localities phosphatic manures are unayail- 
mg, the intelligent obsers ation of this apparently anomalous fact 
may there also lead to the discoyerv of yaluable deposits of 
mineral phosphates. 
In the fourth place, it has been stated in the beginning of this 
paper, that a purely mineral superphosphate may fail to produce 
good turnips, because in addition to the phosphoric acid it does 
not proyide the crop with the requisite amount of potash, lime, 
and organic food, which it finds in land of a better tlescription. 
This part of our subject deseryes a careful examination, inas- 
much as it has been stated that the exclusiye use of mineral 
