At no period in the progress of civilisation have the advantages to be derived from the study of nature been so highly appreciated as at the present day, when descriptions and representations of the various objects by which we are surrounded, or which have been observed in distant countries, are issuing from the press in a variety of forms calculated to attract the attention and to gratify the taste of almost every class of society. Only a few years ago, Natural History was held in some degree of contempt by the enlightened as well as by the ignorant; its cultivators were considered as triflers, wasting their energies upon that which could profit nothing; and the information which it affords was looked upon as unworthy of the attention of persons fitted for intellectual pursuits. Now, it is raised in popular estimation to the highest dignity, and is pronounced to be a science capable of exercising the most splendid talents, and of affording pleasure to the most improved minds. Of the several changes that have recently taken place in society this is not the least important. The diversified productions of Nature,--those objects, in the formation of which have been exercised unlimited wisdom and power,--are not now considered beneath the notice of the wisest of the sons of men. It still, however, remains to be perceived, that in the construction of the familiar fly that buzzes through our apartments, not less than in the frame of the mighty elephant,--in the simple blade of grass that springs from between the stones of the pavement, not less than in the knotted oak or the graceful palm,--in the small cube of salt, not less than in the granitic mountain or the volcanic cone,--there is something of a mysterious nature, the comprehension of which would be a much more glorious achievement than any that the human intellect has yet performed. The ship that carries the adventurous merchant over the great ocean is an object worthy of our admiration; but how complicated is its apparatus, compared with the fins of the most common fish! The balloon that floats calmly in the atmosphere,--what an unwieldy instrument is it, compared with those beautiful organs of Divine workmanship by which the swallow is conveyed from the equatorial to the polar lands, or pursues its prey through the pathless air!