72 MASSACHUSETTS HORTICULTURAL SOCIETY. 



which it otherwise could not do, and hence may act as a fertilizer, 

 but indirectl}'. These diverse conditions of land, of season, and of 

 crop, all complicate the subject, and offer sources for error in inter- 

 pretation, so that, notwithstanding the differences of opinion 

 among farmers as to the usefulness of applications, we are satisfied 

 from the few cases where simple causes have been eliminated from 

 the mass of possibilities and stated, that chemicals do offer a sub- 

 stitute for dung to fertilize our fields, and that it is the fault of tlie 

 farmer alone if he use them unprofitably. 



Lcander Wetherell asked Dr. Sturtevant for a detailed account 

 of his experiments. Could he bring a case where stable manure has 

 been used continuously for a long series of yearn without improving 

 the soil ? Or could he give a case where chemicals have been thus 

 used, where the fertilit}' of the soil has been kept up and im- 

 proved ? He thought the doctor manifestly undervalued the reported 

 results of the German Experiment Stations. Prof. Johnson, the 

 Director of the Connecticut Experiment Station at New Haven, 

 Mr, Wetherell said, incorporated into his valuable book, "How 

 Crops Grow," the tables of Prof. Wolff, of the Royal Academy of 

 Agriculture, at Hohenheim, Wurtemberg. The speaker doubted 

 whether Lawes and Gilbert's experiments, if repeated here, would 

 produce the same results as reported on their farm at Rothamstead. 

 He was slow to believe that three specifics, nitrogen, phosphoric 

 acid, and potash, for example, make a universally complete manure 

 in all places and for all time. Some soils are hungry for phos- 

 phoric acid, and have an abundance of potash ; wh}' use potash 

 where it is not needed? The same ma}' be true of nitrogen. Let 

 farmers and gardeners interrogate their soil with reference to these 

 chemicals and use what is needed, and not subject themselves to 

 the expense of purchasing what the soil already contains an 

 abundance of in a soluble condition. He believed in experimenting. 



Dr. Sturtevant said that his remarks had been righth' understood. 

 The German experiments are the most valuable we have, and are 

 thoroughl}' trustworthy^ but he took the liberty of not deferring to 

 authority when he knew better himself. He did not think the 

 experiments described last week would bear out the interpretation 

 given them. 



Mr. Fuller asked, if the straw and vegetable matter from the 

 barnyard were of no account, how we could enrich soils b}' turning 

 in green crops, as sometimes practised. 



