HORTUS GRAMINEUS WOBURNENSIS. 123 



In one instance, beds of these soils (No. II. and No. VIII. ex- 

 cepted) were arranged in the order in which they have just now 

 been mentioned. Seeds of all the grasses peculiar to each soil 

 were sown on distinct spaces of each bed. The seeds of the dif- 

 ferent grasses vegetated on all the soils, except on the inert peat 

 (No. XII.), which remained completely barren. In the ensuing 

 season, it was remarkable to see the different degrees of luxu- 

 riance exhibited by the same species of grass on different soils. 

 The superior grasses, or those which constitute the produce of 

 rich ancient pasture lands, formed nearly a perfect convex ridge of 

 grass ; beginning at the poor siliceous sandy soil (No. I.), where 

 they were the most diminutive, they gradually increased in luxu- 

 riance, till they reached the bed of rich alluvial soil (No. IX.), 

 and afterwards decreased in the quantity of produce, till they ter- 

 minated at the inert peat (No. XII.). It is of importance to 

 observe, however, that after the second year, this order of luxu- 

 riance did not continue in the same proportion. The rich sili- 

 ceous sandy soil, on the fourth and fifth year, was greatly inferior 

 in produce to what it was on the second and third, and the pro- 

 duce of the poor siliceous sandy soil decreased annually in quan- 

 tity after the second year. The produce of the sandy loam, and 

 clayey loam, continued much the same ; but the rich alluvial soil, 

 and rich clayey loam, increased in the quantity of produce till the 

 fifth year, and have since continued, with but a trifling diminution 

 in the weight of their annual crops, though no manure in any 

 instance has been applied. 



By referring to the details which shew the composition of the 

 rich siliceous sandy soil, which soonest became deficient of produce, 

 it appears, that the finely divided matter contains more of decom- 

 posing vegetable matter, in proportion to the earthy ingredients, 

 than that of the rich alluvial soil, and of the clayey loams. The 

 proportion of sand to the finely divided matter is likewise much 

 greater in that soil than in the others, whose productive powers 

 seemed rather to increase for five successive years. 



A space of the poor siliceous soil was richly manured, and the 

 produce of grass for two years exceeded that of the rich siliceous 

 soil which had no manure : but on the fifth year was so much re- 

 duced, as hardly to equal its original produce. These facts con- 

 firm the opinion, that certain soils may produce large crops of grain 

 or other annual crops, but are nevertheless unfit for the production 

 of the superior perennial grasses. 



