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INTRODUCTION. 



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 correct- 

 ing 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 saUne 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 oljservation, may serve as an instance to point out the importance of 

 a mixture of such grasses as possess some difference in the qualities of their nutritive matter ; 

 and at the same time they will shew, that the bitter extractive is efficacious in correcting the 

 ovci'-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 



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Other with a variety of the natural grasses, for experiment^ with a portion of white clover. Tlie 



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two fields were depastured with sheep. In the enclosure of white clover a considerahle quan- 

 tity of cock's-foot grass grew on the edge of the fence ; it was of a very harsh quality, from its 



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unfavourable situation, and consisted almost entirely of culms. . In a few days the sheep went , 

 to this grass, and ate it down entirely, though there was a profusion of the white clover. In 

 the course of time many of the sheep became affected with the disease termed red-wate?% of 

 which several died. But in the adjoining field, which contained the natural grasses, cock's-foot 

 grass, rough-stalked meadow grass, rye-grass, foxtail-grass, and white clover, the sheep were 

 not affected with that, nor any other disease, and they left untouched the stems of the cock's- 

 foot, which were here of a more tender succulent nature, than those on the edges of the other 

 field, which were so greedily devoured by the clover sheep. 



It may remain only to observe, that if the hard stalks of the cock's-foot in the clover field 

 had ])een in sufficient quantity, they would most probably have prevented the disease from 

 attacking the sheep; but this could not have been by virtue of the (/^t/ /Are only of the culms, 

 because in the adjoining field, where every thing was contrary to disease, the sheep rejected th 

 culms altogether. The dry, or mechanical action of the culms, was here wanting ; yet the ani- 

 mals continued healthy, and fattened, because the bitter extractive was in greater proportion in 

 the leaves or herbage than in the culms which they rejected, and also proved beneficial, though 

 combmed with succulent food, which could have nothing of the action of the dry hay or straw 

 before mentioned. 



X 



The succulency, or the quantity of superfluous moisture contained in the food of cattle and 

 the relative proportions which the sahne matter, and bitter extract, bear to the gluten, sugar, 

 and mucilage of the nutritive matters of different plants, influencing thus their nutritive powers 

 when used in a green state ; these properties, therefore, will be particularly considered in csti- 



