Jethro Tull's theory, from the day it was formulated, has been the subject of controversies, extending to the present day. It is not intended to reproduce here the theory as it appears in the Horse-hoeing Husbandry. This has been done repeatedly and has led both to high praise and vigorous criticism. Nor do we intend to make another critical study of the theory itself. There are grounds, as it seems, for Lord Ernle's views as well as for Mr Marshall's. But if Tull's work itself is not to be analysed, being absolutely outside our scope, its importance, in the light of the agricultural situation in mid-eighteenth-century France, cannot be too strongly emphasized.

Certain points are apparently agreed to be Tull's chief legacies to the new agricultural conceptions as a whole: clean farming, economy in seeding, drilling, the worthlessness of manures, and finally, the maxim that the more the irons are among the roots, the better for the crop. While Lord Ernie praises him as the first to practise what is nowadays successfully applied at Rothamsted —i.e. a highly scientifically developed agriculture—Mr Marshall, besides criticizing his physiological theories, points out three major ‘heresies’: his opinions on the use of manures, his theory of perpetual cultivation of corn, and his advocation of a drastic reduction of seed employed per acre. All this may be excellent for the purposes of English agriculture. That Tull's main ideas might have been either discovered or suspected before him, that his drill had been long known both in Spain and in some parts of England, is perfectly true. But in France, it was the first time that a scientifically constructed and complete agricultural theory had appeared. Hitherto, the names of Grew, Evelyn, Woodward, Bradley, etc., were almost completely unknown to the French public. So were their theories (which seem to have roused less interest than those of Tull, even in England itself). Other reformers may have been suspicious of Tull's ‘sovereign treatment for all cases’ in England. These other reformers were at the time unknown in France. Tull had the luck of being imported as the sole dispenser of an agricultural panacea at the time when theories coming from England were highly esteemed.