Book VI. PASTURE GRASSES. 8f?7 



in them, to furnish as far as possible to the different grasses those soils which seem most favorable to their 

 growth ; a few varieties being adopted for the purpose of ascertaining the effect of different soils on the 

 same plant. The grasses were either planted or sown, and their produce cut and collected, and dried at 

 the proper seasons, in summer and autumn, by Sinclair, his Grace's gardener. For the purpose of deter- 

 mining) as far as possible, the nutritive powers of the different species, equal weights of the dry grasses 

 or vegetable substances were acted upon by hot water till all their soluble parts were dissolved ; the solu- 

 tion was then evajwrated to dryness by a gentle heat in a proper stove, and the matter obtained carefully 

 weighed. This part of the process was likewise conducted with much address and intelligence by Sinclair, 

 by whom all the following details and calculations are furnished. The dry extracts supposed to contain 

 the nutritive matter of the grasses, were sent to me for chemical examination. The composition of some 

 of them is stated minutely; but it will be found from the general conclusions, that the mode of deter- 

 mining the nutritive power of the grasses, by the quantity of matter they contain soluble in water, is 

 sufficiently accurate for all the purposes of agricultural investigation." (Agr. Chem. npp.) 



5148. The leading results of these experiments we have endeavored to present in a tabular view; farther 

 details will be found in the paragraphs (antecedent and posterior) referred to in the first column. On the 

 other columns of the table, it may be observed, that the height is given more by a guess than measure- 

 ment, and after the appearance of the plants in a state of nature or medium sous, it is to be regretted, 

 that the height of the plants at Woburn, were not included in the published details. The time of flower- 

 ing is given, as it took place at Woburn, on which it is observed, that " to decide positively the exact 

 period or season, when a grass always comes into flower, and perfects its seed, will be found impracticable ; 

 for a variety of circumstances interfere. Each species seems to possess a peculiar life in which various 

 periods may be distinctly marked, according to tha. varieties of its age, of the seasons, soils, exposures, and 

 mode of culture." 



5149. The soils, as denominated in the column devoted to them, are thus described. 1st, By loam, is 

 meant any of the earths combined with decayed animal, or vegetable matter, 2nd, Clayey loam, when the 

 greatest proportion is clay. 3d, Sandy loam, when the greatest proportion is sand. 4th, Brown loam, 

 when the greatest proportion consists of decayed vegetable matter. 5th, Rich black loam, when sand, clay, 

 animal, and vegetable matters are combined in unequal proportions, the clay greatly divided, being in the 

 least proportion, and the sand and vegetable matter in the greatest. The terms light sandy soil, light 

 brown loam, &c. are varieties of the above, as expressed. The abbreviations of the names of books and 

 native soils, will be found in common with all the other abbreviations used in this work explained in the 

 General Index. 



5150. On the nutritive products, Sir H. Davy has the following valuable remarks, some 

 of which on the operations in the animal economy of the different substances, composing 

 the nutritive matter, the agriculturist will find useful, as applied to the tables before given 

 (4598. 4738, &c.) of the nutritive products of the corns, legumes, and rootg. The only 

 substances which Sir H. Davy detected in the soluble matters procured from the grasses, 

 are mucilage, sugar, bitter extract, a substance analogous to albumen, and different sa- 

 line matters. Some of the products from the aftermath crops, gave feeble indications 

 of the tanning principle. In the experiments made on the quantity of nutritive matter 

 in the grasses, cut at the time the seed was ripe, the seeds were always separated : and 

 the calculations of nutritive matter made from grass and not hay. 



5151. The order in, which these substances are nutritive, is thus given : " Jhe albumen, sugar, and mu- 

 cilage, probably when cattle feed on grass or hay, are for the most part retained in the body of the animal ; 

 and the bitter principle, extract, saline matter, and tanning, when any exist, probably for the most part 

 are voided in the excrement, with the woody fibre. The extractive matter obtained by boiling the fresh 

 dung of cows, is extremely similar in chemical characters to that existing in the soluble products from the 

 grasses. And some extract, obtained by Sinclair from the dung of sheep and of deer, which had been 

 feeding upon the lolium perenne, dactylis glomerata, and trifolium repens, had qualities so analogous to 

 those of the extractive matters obtained from the leaves of the grasses, that they might be mistaken for 

 each other. The extract of the dung, after being kept for some weeks, had still the odor of hay. Sus- 

 pecting that some undigested grass might have remained in the dung, which might have furnished 

 mucilage and sugar, as well as bitter extract, I examined the soluble matter very carefully for these sub- 

 stances. It did not yield an atom of sugar, and scarcely a sensible quantity of mucilage." Sinclair, in com- 

 paring the quantities of soluble matter afforded by the mixed leaves of the lolium perenne, dactylis 

 glomerata, and trifolium repens, and that obtained trom the dung of cattle fed upon them, found their 

 relative proportions, as 50 to 13. 



5152. From these facts it appears probable that the bitter extract, though soluble in a large quantity 

 of water, is very little nutritive; but probably it serves the purpose of preventing, to a certain extent, the 

 fermentation of the other vegetable matters, or in modifying or assisting the function of digestion, and 

 may thus be of considerable use in forming a constituent part of the food of animals. A small quantity of 

 bitter extract and saline matter is probably all that is needed, and beyond this quantity the soluble mat- 

 ters must be more nutritive in proportion as they contain more albumen, sugar, and mucilage ; and less nu- 

 tritive in proportion as they contain other substances. 



5153. In cotnparing the composition of the soluble products afforded by different crops from the same 

 grass. Sir H. Davy found, in all the trials, the largest quantity of truly nutritive matter, in the crop cut when 

 the seed was ripe, and least bitter extract and saline matter ; most extract and saline matter in the autum- 

 nal crop ; and most saccharine matter in proportion to the other ingredients, in the crop cut at the time of 

 flowering. 



51.54. The greater proportion qf leaves in the Spring, and particularly in the late autumnal crop, accounts 

 for the difference in the quantity of extract; and the inferiority of the comparative quantity of sugar in 

 the summer crop, probably depends upon the agency of light, which tends always in plants to convert sac- 

 charine matter into mucilage or starch. Amongst the soluble matters afforded by the different grasses, 

 that of the elymus arenarius {fig. 543 a.) was remarkable for the quantity of saccharine matter it contain- 

 ed, amounting to more than one-third of its weight. The soluble matters from the different species of 

 festuca, in general afforded more bitter extractive ^matter, than those from the different species of poa. 

 The nutritive matter from the seed crop of the poa compressa was almost pure mucilage. The soluble 

 matter of the seed crop of phleum pratense, or meadow cat's-tail, ai^xdeA more sugar than any of the 

 poa or festuca species. The soluble parts of the seed crop of the holcus mollis, and holcus lanatus, con- 

 tained no bitter extract, and consisted entirely of nmcilage and sugar. Those of the holcus odoratus 

 afforded bitter extract, and a peculiar substance having an acrid taste, more soluble in alcohol than in 

 water. All the soluble extracts of those grasses, that are most liked by cattle, have either a saline or 

 subacid taste; that of the holcus lanatus is similar in taste to gum arable. Probably the holcus lanatus, 

 which is so common a grass in meadows, might be made palatable to cattle by being sprinkled over with 

 salt. 



5155. No difference wasfouAd in the nutritive produce of the crops of the different grasses cut at the same 

 season, which would render it possible to establish a scale of their nutritive powers ; but probably the solu- 

 ble matters of the aftermath crop are always from one-sixth to one-third less nutritive, than those from 

 the flower or seed crop. In the aftermath the extractive and saline matters are certainly usually in ex- 

 cess ; but the aftermath hay mixed with summer hay, particularly that in which the fox-tail and soft 

 Brasses are abundant, would produce an excellent food. .^ 



