•204 



On Superphosphate of Lime. 



for nitrate there can be no reason why we should not obtain a 

 cheaper supply. 



As to the practical application of nitrate with salt, I speak 

 with diffidence, but I should look to it more for curing defects 

 in a crop arising from season or from poverty of soil than for 

 raising a good crop to a very high figure upon good land. Indeed 

 in looking over the experiments made 10 years ago, 1 find that 

 nitrate sometimes does not act at all upon good land. 



We all know, however, how apt wheat is to turn off from frosts 

 or from wireworm in February, and 1 do not think it would be 

 at all rash to say that nitrate, used with judgment in such cases as 

 a cordial to the sick plant, would almost enable us to control 

 this source of uncertainty in the yield, and raise 20 bushels to 28, 

 as it did with me, at a very moderate cost certainly for an extra 

 quarter of wheat. 



Above all I think nitrate may be most valuable upon cold 

 undrained clays, as we know it indeed to have been. I do not 

 of course mean that any clays should remain undrained — but 

 many are undrained, and for want of funds are likely long to 

 remain so. It is an old practice on heavy undrained land to dress 

 the chilled wheat near the furrows with pigeons' dung. The 

 nitrate would act in the same manner. Our forefathers were 

 limited in such applications by their very narrow supply of arti- 

 ficial manures containing nitrogen, doves' dung only, or soot. It is 

 the feature of the last 10 years that wide beds of nitrate, and now 

 of phosphates, whole pyramids too, one may say, of guano, have 

 been laid open to us. Their practice, therefore, should widen in 

 our hands as our resources have widened. 



Pusey, August 21, 1851. 



XIII. — On Superphosphate of Lime: its Composition, and the 

 Methods of Making and Using it. By J. Thomas Way, Con- 

 sulting Chemist to the Royal Agricultural Society of England. 



Of the different kinds of artificial manures now in use in this 

 country, guano and superphosphate of lime are undoubtedly the 

 most important and most extensively employed. Of the former, 

 more than 100,000 tons are annually consumed in England and 

 Wales ; and although it is impossible to form anything like a 

 correct estimate of the extent to which the superphosphate of 

 lime is manufactured, it is evident from the number of persons 

 engaged in its production, and its extended and still extending 

 application for the turnip crop, that the quantity annually con- 



