And yet, by Hercules! a single invention before now has elevated men to the rank of gods; and how many an individual has had his name immortalized in being bestowed upon some plant which he was the first to discover, thanks to the gratitude which prompted a succeeding age to make some adequate return! If it had been expended solely upon the plants which are grown to please the eye, or which invite us by their nutrimental properties, this laborious research on the part of the ancients would not have been so surprising; but in addition to this, we find them climbing by devious tracts to the very summit of mountains, penetrating to the very heart of wilds and deserts, and searching into every vein and fibre of the earth—and all this, to discover the hidden virtues of every root, the properties of the leaf of every plant, and the various purposes to which they might be applied; converting thereby those vegetable productions, which the very beasts of the field refuse to touch, into so many instruments for our welfare. CHAP. 2. (2.)—THE LATIN AUTHORS WHO HAVE WRITTEN UPON THESE PLANTS. This subject has not been treated of by the writers in our own language so extensively as it deserves, eager as they have proved themselves to make enquiry into everything that is either meritorious or profitable. M. Cato, that great master in all useful knowledge, was the first, and, for a long time, the only author who treated of this branch[510] of learning; and briefly as he has touched upon it, he has not omitted to make some mention of the remedial treatment of cattle. After him, another illustrious personage, C. Valgius,[511] a man distinguished for his erudition, commenced a treatise upon the same subject, which he dedicated to the late Emperor Augustus, but left unfinished. At the beginning of his preface, replete as it is with a spirit of piety,[512] he expresses a hope that the majestic sway of that prince may ever prove a most efficient remedy for all the evils to which mankind are exposed. CHAP. 3.—AT WHAT PERIOD THE ROMANS ACQUIRED SOME KNOWLEDGE OF THIS SUBJECT.