EXPERIMENTS ON WHEAT. 175 



The season of 1845 was iiu)rc favorable for wheat, tlian that of 

 1844, and the crops on all the plots were better. On plot No. 3, 

 whieli had no manure last year, or this, the yield is 23 bushels per 

 acre, ajrainst 15 bushels last year. 



Lust year, the 14 tons of barn-yard manure Lrave an incrense of 

 only 5i bushels per acre. This year it gives an increase of nearly 

 9 bushels per acre. 



"Do you mean," said the Deacon, "that this plot, No. 2, had 

 14 tons of manure in 1844, and 14 ions of manure again in 1845 ?" 



" Precisely that. Deacon," suiil 1, •' and this same plot has receiv- 

 ed this amount of manure every year since, up to the present time 

 — for these same experiments are still continued from year to year 

 at Hothamsted." 



" It is poor farming," said the Deacon, "'and I should think the 

 land would get too rich to L'row wheat." 



" It is not so," said I, "and the fact is an interesting one, and 

 teaches a most important lesson, of which, more hereafter." 



Plot 5, last year, received 700 lbs. of superphosphate per acre. 

 This year, this plot was divided ; one half was left without ma- 

 nure, and the other dressed with 252 lbs. of pure carbonate of 

 animonia per acre. The half without manure, (5a), did not pro- 

 duce quite as much grain and straw as the plot which had received 

 no manure for two years in succession. But the wheat was of 

 better quality, weighing 1 lb. more per busliel tlian the other. 

 Still it is sufficiently evident that superphosphate of lime did no 

 good so far as increasing the growth was concerned, either the first 

 year it was applied, or the year following. 



The carbonate of ammonia was dissolved in water and sprinkled 

 over the growing wheat at three different times during the spring. 

 You see this manure, wliieli contains no mineral matter at all, gives 

 an increase of nearly 4 bushels of grain per acre, and an increase 

 of 887 lbs. of straw. 

 " Wait a moment," said the Deacon, " is not 887 lbs. of straw to 



' The mannrpp termod PHporphoisphafo of lime and phosphate of potas?, were 

 made by acting upon bono-aph hv moans of sulplmiic acid, and in the ca-c of 

 the potass salt nontralizins the compound thus obtained, by means of pearl-ash. 

 For the sn-erphoshate of lime, the proportions were. ^ parts bone-ash. .3 parts 

 water, and -i parts sulphuric acid of sp. p:r. l.'^: and for the phosphate of potass. 

 4 parts bone ash. water as needed. :^ parts snlphuric acid of sp. pr. 1.84 ; and an 

 equivalent amount of pearl ash. The mixtnres. of course, lost weight consider- 

 ably by the evolution of water and carbonic acid. 



3 The medicinal carbonate of ammonia; it was dissolved in water and top- 



dress<^d. ■■ -,v n ■ . 



* Plot T}. was 2 lands wide (in after vears. respeetivelv. .'ia and .W : 5' con lift- 

 ing of 1 aitf-rnate one fourth lengthsacross both landB, and .5^ of the 2 remain- 

 ing oni'-fourth lenirtlis. 



* Top-dressed at once. • Top-dressed at 4 intervale. ^ Peruvian. * IcliaDoe. 



