8 HORTUS GRAMINJEUS WOBURNENSIS. 



sionally fed in the field, and on examining the insoluble portion of 

 the dung, (after separation from the soluble parts), nearly one- 

 fourth part in weight consisted of the woody fibre of hay, which 

 evidently had afforded the extra quantity of bitter extractive to 

 the dung. 



The sheep ate of the hay from choice, and not necessity, and 

 it is more than probable that the bitter extractive it contained, 

 was, under such circumstances, the most valuable part of its 

 nutritive matter, in supplying the deficiency of it in the turnips. 



It is worthy of observation here, that the leaves or herbage of 

 the common pasture grasses, contain nearly the like proportion of 

 bitter extractive as that in the dung ; the sheep, therefore, in this 

 instance, had taken that proportion of hay which, combined with 

 the turnips, formed a natural food, or that which had nutritive 

 qualities analogous to natural pasture. 



The dry fibre of the hay or straw given with turnips, may also 

 assist mechanically in correcting the watery nature of this food 

 in the cold season of the year in which it is given to sheep, when, 

 an excess of moisture may be more hurtful than in a warmer 

 season. 



In some plants there is a comparative excess of saline matter, 

 and when such plants are given unmixed with any other to 

 cattle, they are most subject to disease, or continue for a length 

 of time before they improve, however abundant the supply. The 

 following facts, which came within my own immediate observa- 

 tion, may serve as an instance to point out the importance of 

 a mixture of such grasses as possess some difference in the quali- 

 ties of their nutritive matter; and at the same time they will 

 shew, that the bitter extractive is efficacious in correcting the 

 over-succulency, or laxative nature of green food, without the aid 

 of dry vegetable fibre. 



Two fields were sown down for pasture ; one with white clover 

 and trefoil only, and the other with a variety of the natural 

 grasses, for experiment, with a portion of white clover. The 

 two fields were depastured with sheep. In the enclosure of 

 white clover a considerable quantity of cock's-foot grass grew on 

 the edge of the fence ; it was of a very harsh quality, from its 

 unfavourable situation, and consisted almost entirely of culms. 

 In a few days the sheep went to this grass, and ate it down en- 

 tirely, though there was a profusion of the white clover. In the 

 course of time many of the sheep became affected with the 



