Imágenes de páginas

itself, and its singular properties were satisfactorily ascertained and established.

This extraordinary menstruum, the most active with which we are acquainted in nature, is now well known by the name of gastric juice, so called from the Greek term for the organ that pours it forth.' Its apparent simplicity of composition is as remarkable as its digestive power: for, in a pure and healthy state, it is a thin, transparent, and uninflammable fluid, of a weak saline taste, and utterly destitute of smell. Its antiputrescent property is of as extraordinary a nature as its digestive : for it will render perfectly sweet the most offensive and putrid food that gipsies, or hungry dogs can be made to swallow, in about half an hour after such food has been exposed to its action. This gastric juice farther possesses, in an equal degree, both these curious powers of dissolution and restoration to sweetness, as well out of the body as in the stomach itself.

How majestically quiet and easy is the common walk of nature ! (employing the term in its usual acceptation as “ a name for an effect whose cause is God”)-how simple are the means she makes use of !-how wonderful in their operation !-how adequate to the end proposed ! Measuring her, as we too often do, by our own imperfect powers, we take it at once for granted, that that which is to us elaborate, must be equally difficult to herself: in tracing her we are apt to overlook the principle of simplicity which is stamped on all her footsteps ; we surround ourselves with a world of machinery, and lose our aim by the mere multiplicity of our agencies ; till accident, in a lucky hour, suggests to us a new and easier track, on entering which we are equally surprised at our own dulness, and at the wisdom that beams before us.

But it is more than time that I should conclude. We have seen in the principal cases which I have selected, how much has sprung from

apparent accident: I shall scarcely expect to be forgiven by this assembly, if I omit to add, that it was only accident in appearance. How many thousand persons had seen an apple fall, before Newton, with respect to whom the observation had been altogether unproductive ? Besides the event of the falling apple, there needed the simultaneous operation of various independent causes to render it an epoch in the history of philosophy. It was necessary that it should be observed by a man at leisure to pursue any train of reflection that should thereby be suggested : it was necessary that it should be noticed by a man of research, and that not as a lawyer,

? Even the stomach itself, when deprived of vitality, has been found acted upon, and, in a manner, digested by it. See John Hunter, on digestion of the stomach after death. Phil. Trans. vol. lxii. Or, J. Hunter's Observations on the Animal Economy, in which this paper is reprinted. VOL. XIII.



not as a theologian,-- not as an anatomist, a botanist, an entomologist, or a chemist, but as a mathematical philosopher. It was farther necessary that the observer should have a certain fund of previous knowledge, and yet, that his mind should not be pre-occu pied. Had the falling apple been observed by Newton when he was absorbed in his admirable investigations concerning light and colors, it might no more have led to the theory of universal attraction and the perfection of physical astronomy, than it would in the contemplation of the most illiterate porter that paces the streets of this metropolis. Let us view these matters aright. It is not chance, but previous design, that in this and other similar instances, brings so many independent circumstances into juxta-position ; just as in the case of two travellers, -one passing from London northwards, the other from York southwards-meeting on the way, the accident of their meeting is a necessary consequence of the previous determinations of both to start at a certain time, and to travel by the same road.

The practical inference we may draw from the whole, and which I would strongly urge upon the younger part of my auditory, is simply this :-Do not hastily relinquish a train of thought suggested by a fresh class of circumstances, even though the prospect of utility be very remote. If the poet spake truly that “ our thoughts are heard in heaven," may not a philosopher remark with equal truth, that our noblest thoughts are suggested in heaven, and that all genius is a species of inspiration ? Among the ancients, when nature was not, as too frequently happens among us, concealed under a thick veil of elucidation, this was unhesitatingly admitted ; as by Plato, by Phædrus, and even by Longinus, the most reserved of ancient critics. They distinguished accurately the enthusiasm or inspiration of genius, from the perturbed suggestions of the connato and Phrenetici; but sought the occasion of both ab extra, and not in the imagination itself. In the latter case, they regarded the bark as driven of necessity, wanting cable and anchor to hold her; in the former, as sailing from choice, because the gale is from a favorable quarter, and the voyage desirable. Under another metaphor they viewed the imagination of the poet, and in its kind and degree, that of every man of genius, as a field in which the Author of Nature produces a set of objects which existed not before ; as a region in which new images and combinations arise, like new plants, under auspicious circumstances of culture or climate, according to the settled laws of the Creator. So fruitful is the womb of nature ! So true is it, that we are all, more or less, the children of circumstances; and it behoves us, therefore, to avail ourselves to the utmost of the circumstances into which we are thrown. Distinguish, then, sedulously between the dictates

of wisdom and of folly, the suggestions of reason and of fancy; but do not abandon a train of inquiry, merely because it seems likely to produce but little.' Remember that lofty trees grow from diminutive seeds; copious rivers flow from small fountains; slender wires often sustain ponderous weights; injury to the smallest nerves may occasion the acutest sensations; the derangement of the least wheel or pivot may render useless the greatest machine of which it is a part ; an immense crop of errors may spring from the least root of falsehood ; a glorious intellectual light may be kindled by the minutest sparks of truth ; and every principle is more diffiosive and operative by reason of its intrinsic energy than of its magnitude.

And let me entreat you, above all things, to avoid the great error of « mistaking or misplacing the ultimate object of knowledge.” For many, says Lord Bacon, « have entered into a desire of learning and knowledge, some upon an inbred and restless curiosity; others for ornament and reputation ; others for contradiction and victory in dispute ; others for lucre and living ; few to improve the gift of reason given them from God, to the benefit and use of men. As if there were sought in knowledge, a couch, whereupon to ease a restless and searching spirit ; or a terrace for a wandering and variable mind to walk up and down in, at liberty unrestrained; or some lofty tower of state, from which a proud and ambitious mind may have a prospect; or a fort and commanding ground for strife and contention; or a shop for profit and sale; and not rather a rich storehouse for the glory of the Creator of all things, and the relief of man's estate.” 2

I“ Les applications du thermomètre dans la physique, la chimie et les autres sciences naturelles, sont innombrables. Les indications qu'il nous donne sont la base de toute la théorie de la chaleur ; il est le régulateur de toutes les opérations chimiques; l'astronome le consulte à chaque instant dans ses observations, pour calculer les déviations que les rayons lumineux émanés des astres éprouvent en traversant l'atmosphère, qui les brise et les courbe plus ou moins, selon sa température. C'est encore au thermomètre que nous devons toutes les connoissances que nous avons sur la chaleur animale, produite et entretenue par la respiration. C'est lui qui fixe dans chaque lieu la température moyenne de la terre et du climat; qui nous montre la chaleur terrestre constante dans chaque lieu, mais diminuant d'inteisité depuis l'équateur, jusqu'aux pôles constamment glacés; c'est encore lui qui nous apprend que la chaleur décroît à mesure que l'on s'élève dans l'atmosphère, vers la région des neiges éternelles, ou qu'on s'enfonce dans les abimes des mers, d'où résultent les changemens progressifs de la végétation à diverses hauteurs. Lorsqu'on voit tant de résultats obtenus par le seul secours d'un peu de mercure enfermé dans un tube de verre, et qu'on songe qu'un petit morceau de ser, suspendu sur un pivot, a fait découvrir le NouveauMonde, on conçoit que rien de ce qui peut agrandir et perfectionner les sens de l'homme, ne doit être d'une légère considération." Biot-Traité de Physique, tom. i. pa. 62.

Bacon's Advancement of Learning, lib. i. ch. 5.


[20 Rest not, then, till you acquire a capacity of rising spontaneously, from the contemplation of the sublime in matter, to that of THE SUBLIMEST in mind ;-to that of the SUPREME REALITY, who comprehends all which he has made, and infinitely more than what, as yet, delights and interests us, within the scope of one grand administration ;-to him whose ineffable character“ gathers splendor from all that is fair, subordinates to itself all that is great, and sits enthroned on the riches of the Universe !."













« AnteriorContinuar »