120 ON NEW AND ACID LAND, 



No. 2 made 7 bushels, 2 pecks, or to the acre, 30.2 

 The same in 1821, after marling, . . 16. 2 & 



Increase average, . . . . .13.3'} 



The second dressing of marl, or the larger quantity, had but 

 little effect in making the increase of crops greater than in 1821. 

 The difference was caused mainly by the greater length of time 

 since the clearing of the land. 



1825. The whole twenty-six acres, including the subjects of all 

 these experiments and observations, were in wheat. The first 

 marled piece, in Exp. 1, was decidedly the best and a gradual 

 decline was to be seen to the latest. I have never measured tho 

 product of wheat from any experiment, on account of the great 

 trouble and difficulty that would be encountered. Even if tho 

 wheat from small measured spaces could be reaped and secured 

 separately, during the urgent labours of harvest, it would be 

 scarcely possible afterwards to carry the different parcels through 

 all the operations necessary to show exactly the clean grain derived 

 from each. But without any separate measurement, all my obser- 

 vations convince me that the increase of wheat, from marling, was 

 at least equal to that of corn, during the first two years, and cer- 

 tainly greater afterwards, in comparison to the product before using 

 marl. 



It was from the heaviest marled part of Exp. 1, that soil was 

 analyzed to find how much calcareous earth remained in 1826 

 (page 78.) Before that time the marl and soil had been well 

 mixed by ploughing to the depth of five inches. One of the 

 specimens of this soil then examined consisted of the following 

 parts half an inch of the surface, and consequently the undecom- 

 posed weeds upon it, being excluded. 

 1000 grains of soil yielded 



769 grains of silicious sand moderately fine, 

 15 finer sand, 



784 



8 calcareous earth, from the manure applied, 



108 finely divided gray clay, vegetable matter, c. 



28 lost in the process. 



1000 



This part, it has been already stated, was originally somewhat 

 lighter than the general texture of the remainder of the land. 



Experiment 4. 

 The four acres marked A D n o were cleared in the winter of 



