HORTUS GRAMINEUS WOBURNENSIS. 3 



has shewn, that the nutritive matter of grasses, or soluble pro- 

 ducts, consist, for the most part, of five distinct vegetable sub- 

 stances, viz. mucilaginous, saccharine, albuminous, bitter ex- 

 tractive, and saline matters ; and that " it is probable that the 

 excellence of the different articles, as food, will be found in a 

 great measure proportional to the quantities of soluble, or nutri- 

 tive matters they afford ; but still these quantities cannot be 

 regarded as absolutely denoting their value : albuminous or glu- 

 tinous matters have the characters of animal substances ; sugar 

 is more nourishing, and extractive less nourishing, than any other 

 principles composed of carbon, hydrogen, and oxygen ; certain 

 combinations of these substances, likewise, may be more nourish- 

 ing than others *." 



A certain quantity of food will keep an animal for a great length 

 of time, without increasing or diminishing its weight in any sensi- 

 ble degree ; but if the quantity of food be sufficiently augmented, 

 under favourable circumstances, the animal becomes fat, and its 

 weight consequently increased. We have no means, however, to 

 ascertain the exact proportions of food required for these two 

 purposes distinctly ; for it depends not on the quantity and qua- 

 lity of the food alone ; the age of the animal, and its exposure to 

 heat or cold, are also concerned in the process. It is likewise 

 evident, that of two animals of the same breed or variety, the one 

 will frequently acquire a much greater weight of flesh in any 

 given length of time than the other, though both shall have been 

 fed on the same kind of food, and in all other respects treated 

 equally. The nutritive powers of the food cannot therefore be 

 determined absolutely, even by these means, though the com- 

 parative merits and value of the different breeds or varieties of 

 animals are thereby fully ascertained ; for it is manifest, that it is 

 not the deficiency of nutritive matter in the food, but want of 

 power in the animal to profit by it. 



* " Agricultural Chemistry." Since the first publication of these pages, the 

 author has had abundant opportunities of proving that the quantities of soluble 

 nutritive matter afforded collectively by all those grasses which constitute the pro- 

 duce of the richest ancient pastures, denotes absolutely the degree of nourishment 

 they afford, as well as comparatively with other and different combinations of 

 grasses ; these will be noticed in the course of the work. With grain, and with 

 farinaceous roots, as the potatoe, &c., the case is different; for the soluble nutri- 

 tive matters of these constitute but a small portion of the nutritive matter they 

 afford, whereas the nutritive matters of the grasses are wholly soluble. 



