WATFOKD NATTJEAL HISTOKY SOCIETY. Iv 



the grasses having entirely pushed them out. In the adjoining 

 plot (11) a great excess of ammonia salts added to the minerals 

 had reduced the number of species from 49 wlien unmanured, to 1 8. 

 At a plot (4) showing a number of so-called "fairy rings," Dr. Gilbert 

 mentioned the curious fact that, although the fungi which grow on 

 fairy rings are exceedingly rich in nitrogen, they grow on places 

 where there is the least nitrogen supplied in manure ; and at 

 another (13) that with cut wheat-straw there was a more compli- 

 cated herbage than without straw, and a much greater increase of 

 produce than the amount of straw added would have led him to 

 expect. 



" Hoos Field," in which about 4^ acres are devoted to experi- 

 ments on the continuous growth of barley ; " Broadbank Field," 

 of about 13 acres, devoted to experiments on the continuous growth 

 of wheat ; and "Geescroft Field," in which about three-quarters of 

 an acre are devoted to experiments on the growth of oats, were 

 then visited in succession. Dr. Gilbert giving the principal results 

 arrived at from the application of different manures. The various 

 results obtained by sowing at different periods of the year, and by 

 applying the manures in varying quantities according to the state 

 of the weather or the difference in climate, were also dilated on by 

 him. In one case he stated that after a heavy dressing of ammonia- 

 salts a quantity of nitrates was found in the drainage waters, which 

 would correspond to a loss of nearly 181bs. of nitrogen per acre, 

 provided an inch of rain had passed as drainage of that strength. 

 On another occasion, after a heavy dresssing of nitrate of soda, the 

 quantity of nitrates found in the drainage water, reckoned in the 

 same way, would be equivalent to a loss of about 1 3lbs. of nitrogen 

 per acre. Thus in wet seasons, such as we have lately had, and 

 might in our climate usually expect, it was the most economical 

 for the agriculturist to apply his nitrogenous manures as a top- 

 dressing to the crops in the spring, whilst the mineral manures, such 

 as superphosphate of lime, etc., might be ploughed in with the 

 seed, as phosphoric acid and potash were in a greater degree 

 retained by the soil, and less liable to be washed away during wet 

 winters. 



Some other fields were then visited, from one of which a distant 

 view of Flamsted Church tower was seen ; and after hearing some 

 particulars of the experiments on various leguminous and potato 

 crops, to which these fields are appropriated, the members took 

 leave of Dr. Gilbert, thanking him heartily for the amount of 

 interesting and valuable information they had received from him.* 



While a few then returned to Harpenden, the majority left the 

 park in an opposite direction, pursuing their way by Hammond's 

 End along bye-roads and across fields to Hcdbourn Bury, where 

 they had been invited to tea by Mr. and Mrs. Arnold. 



After a substantial and most acceptable repast, for which the 



* Only a few of the points treated upon have been but briefly alluded to in 

 this report. 



