JExperiments upon Swedes. 157 



those artificials, which, like nitro-phosphate, ammonia-phosphate, 

 blood-manure, &c., convey the idea of manures rich in nitroojen 

 or ammonia, when prepared for turnips, hardly contain any ni- 

 trogen. Still I am informed, on good authority, that there are 

 many soils on which the very cheapest manure that can possibly 

 be used for turnips is guano. 



How can these contradictory facts be reconciled ? I l:)elieve 

 only when tlie subject is thoroughly investigated, without direct 

 reference to the immediate advantages that will result from the 

 investigations to the farmer. It is by laborious, long-continued, 

 and expensive field experiments, and purely theoretical investi- 

 gations, like those referring to the assimilation of nitrogen by 

 plants, and carried out at present in a masterly manner in Mr. 

 Lawes's laboratory at Rothamsted, that, after all, most practical 

 questions have to be answered. The establishment of a single 

 truth in science, especially if it refers to living organisms, is often 

 the work of the lifetime of a man. Many excellent experiments, 

 whether made in the field or in the laboratory — experiments con- 

 ceived in a'^' philosophical spirit, and carried out by men accus- 

 tomed to perform accurate researches with the most praiseworthy 

 industry, perseverance, and personal expense, too — have had the 

 fate of being denounced as unpractical. Such experiments neces- 

 sarily must appear quite mysterious to the uninitiated ; but, after 

 all, they are much more likely definitely to settle important prac- 

 tical questions than many so-called practical trials, made for the 

 special information of the farmer. 



With a view of throwing some light on the action of ammonia 

 on root-crops, more especially on swedes, I made some experi- 

 ments in 1856 and 1857, and have now the pleasure of laying 

 the results of those experiments before the Roval Agricultural 

 Society. I would notice particularly that my object was not to 

 ascertain how large a crop of turnips I could obtain by the 

 application of certain mixed manures, but to determine, if pos- 

 sible, whether on our farm and the soils in our neighbourhood 

 we can dispense with the use of ammonia or not, and what 

 manuring constituents are likely to be of the greatest benefit to 

 this root-crop. 



Experiments upon Swedes in 185G. 

 Skirving's Liverpool Stccdc, 



The field on which the following experiments were made was 

 sown with rye in the autumn of 1855, to afford an early bite for 

 our sheep ; but the green rye having partially failed, the field 

 Avas ploughed up early in spring and repeatedly worked with the 

 cultivator and harrows before the seed was sown. 



