EXPERIMENTS ON WHEAT. 175 



The season of 1845 was more favorable for wheat, than that of 

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

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

 acre, against 15 bushels last year. 



Last year, the 14 tons of barn-yard manure gave an increase of 

 only 5 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 tons of manure again in 1845 ? " 



" Precisely that, Deacon," said I, " 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 Rothamsted." 



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

 land would get too rich to grow 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 Ibs. of superphosphate per acre. 

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

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

 ammonia 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 Ib. more per bushel than 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, which contains no mineral matter at all, gives 

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

 of 887 Ibs. of straw. 



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



2 The manures termed superphosphate of lime and phosphate of potass, were 

 made by acting upon bone-ash by means of sulphuric acid, and in the case of 

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

 For the superphoshate of lime, the proportions were, 5 parts bone-ash. 3 parts 

 water, and 3 parts sulphuric acid of sp. gr. 1.84 ; and for the phosphate of potass, 

 4 parts bone ash, water as needed, 3 parts sulphuric acid of sp. gr. 1.84; and an 

 equivalent amount of pearl-ash. The mixtares.'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 ard top- 

 dressed. 



4 Plot 5. was 2 lands wide (in after years, respectively, 5a and 56) ; 5 1 ccnMst- 

 ing of 2 alternate one-fourth lengths across both lands, and 5 2 of the 2 remain- 

 ing one-fourth lengths. 



6 Top-dressed at once. Top-dressed at 4 intervals. T Peruvian. 8 Ichaboe. 



