that Genius without sense, is a name without a meaning.

The perversions, or deficiences here spoken of, were extreme; but who can doubt, and none can deny, but that they may exist in every variety of degree in others; more or less perhaps in all; and, of course, the perfection or imperfection of knowledge dependent upon that sense, as far as regards color, must correspondently vary.

What is here stated of an aberration of sense, may, with equal truth, and greater generality, be extended to different powers of it. We have within our daily observation, cases that range from perfect vision to perfect blindness; and varieties of these again in the myoptic and presbytic eye, or long and short sightedness; not to advert to the muscæ volitantes. The mistakes of Dr. Johnson, in his Tour to the Hebrides, can be referred to this cause only. And, to speak logically, whilst an acquaintance with the modes and accidents of bodies; as their form, color, rest, motion, relation, similitude, &c. &c., which constitute all we know of them, depends upon a perfection of the organs of sense, so whenever those organs are defective, that acquaintance must be imperfect.

In further illustration of this argument, I will beg leave, very briefly, to advert to that branch of Logic which respects definition. Definition, as many you well know, consists in bringing together the general nature and essential difference

of

of an object. Now the general nature, even what is called the proximate general nature, exists in those properties which are apparent to all mankind; and may be perceived without much labour. But the essential difference commonly resides in some minute, obscure, or at least not very obvious quality of it; and, therefore, can seldom be discovered but by accurate observation, and diligent research; after multiplied enquiries, and faithful comparisons. And how can he examine accurately, or compare faithfully, whose organs of vision are defective? Thus, for example, a horse and an ox agree in many points; they are both quadrupeds, are both covered with hair, have many members in common &c.; this constitutes their general nature. But they vary in the hoof; the one being whole, the other divided; this constitutes their essential difference. An imperfect eye might discern the first; but a correct eye, and patient investigation, such as were possessed by a Linnæus, will discover both. To a myoptic eye they might for ever have been confounded.

Thus I have endeavoured to show, that all knowledge is dependent upon the senses; and that the degree of perfection of knowledge, will vary with the degree of perfection of the organs of It is true that the quantity of knowledge will vary, if I may use the language of the mathematicians, in a compound ratio, with the perfection of those organs, and the exercise of

sense.

them; but no perfection in the former can supersede the necessity of the latter; although greater diligence, with less perfect organs, may more than compensate such deficiency: this is the tortoise beating the hare. Where a perfect organization is united to incessant industry in collecting and combining ideas, there will result Genius. But it would still be wrong to conclude, that feeble organs cannot be made strong by discipline; and industry we are certain is within our control. An opposite opinion would contradict daily experience; and fatally repress that application, which we may pronounce, almost with certainty, would lead to success.

I might here dwell on that most encouraging consideration, the almost illimitable improvements of which the organs of sense are susceptible; a point of primary importance in the education of the mind.

What a stimulus to exertion do we discover in the Painter, who, from a cultivation of the organ of vision, can distinguish shades of colours where an unpractised eye can perceive none. In the Optician, who will instantly decide upon the graduation of an instrument, which another would have to examine with a microscope. In the Musician, who hears nothing but discords in music, where an untutored ear is sensible of nothing but harmony. Or, to mention more homely examples, how accurately will a Farmer

pronounce upon the weight of an ox, or the size of a field, or even the quantity of a crop! whilst a Sailor at sea, will measure his distance from the land, with a precision almost incredible. And I remember to have heard or read of a blind man who could tell the size of a room by the stamping of his foot. Here we find one, who can write the Lord's Prayer and the Creed within the compass of a sixpence; whilst there is another, who will dissect with ease, and explain with accuracy, the anatomy of a flea. Need I mention, that the parallel lines of micrometers, are sometimes drawn within the ten thousandth part of an inch of each other*; and of the correctness of this parallelism, the eye is required to judge! whilst to a practised touch, the one sixty thousandth part of an inch, is declared to be sensible! Who, after these examples, will set bounds to the improvement of the senses?

But perhaps it will be contended, that Genius

* Mr. Troughton, in a paper read before the Royal Society, observes, "I must here remark, that Smeaton has represented the greatest degree of accuracy that can be derived from vision,

1 4000

in judging of the coincidence of two lines, at part of an

inch. From this it may fairly be inferred, that he had not CULTIVATED the power of the sight, as he had done that of the

1

touch; the latter of which he rendered sensible to the 60,000 It is now quite common to divide the

part of an inch.

puts in a higher claim than has hitherto been assigned it that it exercises itself in creating the fine imaginings of the Poet, the sublime sentiments of the Orator, or in expatiating in the profounder regions of philosophy. To this claim let us now direct our attention. And as the Poet professes to have taken larger draughts of this inspiring spirit than other men, let us first examine the fruits of it in his labours. We shall still find it grounded upon sense; the genuine offspring of sense and industry.

Homer, the prince of Geniuses of this class, describes Neptune in the following lines; which Longinus extols, not only as peculiarly grand, but altogether unearthly; an opinion which he

1

seaman's sextant to 10, and a good eye will estimate the half of it; which on an eight-inch radius is scarcely 10,000 ofan inch. And such is the certainty with which these quantities are seen, that a seaman will sometimes complain that two pair of these lines will coincide at the same time; and this may happen, and yet no division of his instrument err, by more than part of an inch. 20,000 By an eye practised in such matters, a coincidence may undoubtedly be ascertained to

1

1

50,000 part of an inch.”

The above observations of that ingenious artist, are strikingly confirmatory of the opinion expressed in this Essay, and highly encouraging to cultivate the organs of sense.