For natural history stands to man’s power over Nature, that is, to his power of being useful to himself and to mankind, in the same relation as do geography, grammar, arithmetic, geometry, political economy; none of them, perhaps, bearing directly on his future business in life; but all training his mind for his business, all giving him the rudiments of laws which he will hereafter work out and apply to his profession.  And even at home, be sure that such studies will bear fruit in after life.  The productive wealth of England is not exhausted, doubt it not; our grandchildren may find treasures in this our noble island of which we never dreamed, even as we have found things of which our forefathers dreamed not.  Recollect always that a great market town like this is not merely a commercial centre; not perhaps even a commercial centre at all:  but that she is an agricultural centre, and one of the most important in England; that the increase of science here will be sure more or less to extend itself to the neighbourhood:  and then lay to heart this one fact.  A friend of mine, and one whom I am proud to call my friend, succeeding to an estate, thought good to cultivate it himself.  And being a man of common sense, he thought good to know something of what he was doing.  And he said to himself:  The soil, and the rain, and the air are my raw materials.  I ought surely then to find out what soil, and rain, and air are; so I must become a geologist and a meteorologist.  Vegetable substances are what I am to make.  And I ought surely to know what it is that I am making; so I must become a botanist.  The raw material does somehow or other become manufactured into the produce; the soil into the vegetable.  I ought surely to know a little about the processes of my own manufacture; so I must learn chemistry.  Chance and blind custom are not enough for me.  At best they can but leave me where they found me, at their mercy.  Science I need; and science I will acquire.  What was the result?  After many a mistake and disappointment, he succeeded in discovering on his own estate a mine of unsuspected wealth—­not of gold indeed, but of gold’s worth—­the elements of human food.  He discovered why some parts of his estate were fertile, while others were barren; and by applying the knowledge thus gained, he converted some of his most barren fields into his most fertile ones; he preserved again and again his crops from blight, while those of others perished all around him; he won for himself wealth, and the respect and honour of men of science; while those around him, slowly opening their eyes to his improvements, followed his lessons at second-hand, till the whole agriculture of an important district has become gradually but permanently improved, under the auspices of one patient and brave man, who knew that knowledge was power, and that only by obeying nature can man conquer her.