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operate both on masses and atoms, are called into action, and hence it is, that the very evolution of a living form depends on the condition, that all these various agents conspire. There is no mystery in animated beings, which time will not at last reveal.” — p. 2.

Not only are living beings the result of the action or equilibrium of a great variety of common purely physical forces, - if we rightly apprehend the statement, — but the living body offers no more or other resistance to these physical forces than a dead carcass.

For “it is a vulgar error, says our author, “that a living being possesses a principle of resistance to external agents, while a dead one submits to them ; both equally change, or, of the two, the living one putrefies and changes the more rapidly.” (p. 6.) “Life and vitality figure away in these visionary speculations (the theories of physiologists) as though they were realities.” (p. 41.) If, indeed, vital, as distinguished from common physical, forces have no existence, we may as well admit the doctrine with which the following sentence concludes. " What, then, are the final impressions left upon our minds by these general considerations ? They teach us, that life never occurs except in regions to which the imponderable agents can have access, an observation which is equally true of vegetable and of animal forms; that elementary organization directly or indirectly arises from the plastic agency of those all-pervading forces.(p. 14.) Surely, the author would disclaim the inference which he here seems to invite.

The scientific readers of Dr. Draper's large volume will find themselves as much mistaken as we were, if they suppose, that, although addressed to chemical philosophers, it is actually filled with original contributions to science. These, if separately presented, would occupy but a moderate space. Indeed, from the discursive and tropically luxuriant style, and from the particularity with which the author enters upon the most detailed explanations of perfectly trite and elementary matters, we should imagine that the treatise may have been originally prepared, and have done service, in the form of popular lectures to medical students. The introductory chapter, in particular, though well enough adapted for that purpose, an ill-natured critic might compare to an omelette soufflée, of which Dumas and Cuvier may have furnished - No. 126.

17

VOL. LX.

the egg, Humboldt, Lyell, and others, the condiment, and Dr. Draper the intumescence.

The author's ingenious views on the rise of the sap in plants, and the circulation in animals, are prefaced by an elementary treatise on capillary attraction. Before we reach his proper observations on the action of light upon foliage, we have two very diffuse chapters to undergo, on the solar spectrum in general, Newton's theory of colors, the calorific and the chemical rays, and a great variety of elementary matters, with which a philosopher of the lowest acquirements might be presumed familiar, or for which, if he would refresh bis school-boy recollections, he might turn to his forgotten text-books. And when at length the interesting experiment comes to be described, (the substance of which we have given in a former page,) the reader's attention is directed, not so much to the point which it was intended to prove, as to the gaudy tints that are reflected by the apparatus upon the wall of the room.

“ This prismatic experiment is one of the most beautiful objects which organic chemistry can offer, carried on in a chamber which would be totally dark, were it not for the intensely colored curves which are cast upon the walls by reflection from the tubes, curves which often are many yards in length, indicating by their gaudy tints and brilliancy the intensity of the sun's light. The tubes and the vegetable leaves glow with the colors in which they are immersed. Meantime the most inter. esting phenomenon which can be witnessed is silently going for. ward; dead and inanimate matter is, under the influence of the plastic beam, putting on the form of organization and life.” —

p. 64.

This reminds us of one of the newspaper articles, emanating from an American observatory, upon the great comet of 1843, about the time of its first appearance. The observer, unfortunately, did not see the comet for wbich he was searching ; but he filled his page with a glowing account of the twilight, and with some miscellaneous observations on the fixed stars.

And, finally, when the nervous principle of plants is considered, — and what that is our readers are already informed, - we are treated, by way of introduction, with a particular account of the five senses; of which the following may serve as a specimen.

“ The optic nerve, which gathers on its retinal expansion the images of outward forms, transmits them to the brain. To that cerebral tract to which it goes, the power is given to be affected by luminous agency; it is immaterial whether that agency consists of undulations of an ethereal medium, or spends itself in producing a chemical change of the retina. The portio mollis of the seventh pair, also, exposes itself in the cochlea of the ear, and having the function of audition committed to it, vibrates correspondingly to those oscillatory movements which constitute sound. So, too, with the olfactory nerve, which, pushing its way through the cribiform plate of the ethmoid bone, expands in a million of ramified branches on the Schneiderian membrane, and is ready to be impressed by odors or smells. There is no such thing as a mutual convertibility of the offices of these different machines ; no vicarious interchange of action ; each one has its own duty to perform, each has to discharge its proper task, and the construction of each is suitably arranged. In human contrivances, the same necessity of result arises; the telescope will not answer for a piano, nor a piano for a telescope."

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p. 100.

Why did not our author add the classical illustration, Ου γαρ σύριγγα κέρκου του χοίρου ποιητέον ? Surely, the doctrine of an ancient savant, one Bottom, “ The eye of man hath not heard, the ear of man hath not seen, man's hand is not able to taste, his tongue to conceive, nor his heart to report," - opposed although it has been in these Mesmeric days, - is now incontrovertibly established. Again :

“ The nervous and optical mechanism of the eye is so arranged as to have entire charge of the reception of impressions conveyed by the luminiferous ether; the auditory mechanism of the ear is constituted so as to receive undulations of gaseous bodies like atmospheric air; and, correspondingly, if intelligence has to be communicated to a distance, and received by other minds through the agency of a visual organ, the motor nerves of the hand are put in action, the fingers move, and letters appear upon the paper." - p. 101.

But the number of these letters is sometimes out of all proportion to the amount of intelligence communicated.

ART. VII.-1. Commerce of the Prairies : or the Journal

of a Santa Trader, during eight Expeditions across the great Western Prairies, and a Residence of nearly nine Years in Northern Mexico. Illustrated by Maps and Engravings. By Josiah Gregg. New York:

Henry G. Langley. 1844. 2 vols. 12mo. 2. Narrative of the Texan Santa Expedition ; com

prising a Description of a Tour through Texas, and across the great Southwestern Prairies, the Camanche and Caygua Hunting-grounds ; with an Account of the Sufferings from Want of Food, Losses from hostile Indians, and final Capture of the Terans, and their March, as Prisoners, to the City of Mexico. With Illustrations and a Map. By Geo. WILKINS KENDALL. New York: Harper and Brothers. 1844. 2 vols. 12mo. Mr. Gregg's book is obviously not the production of a very practised writer. The interest of his narrative is in some degree impaired by introducing episodes by way of illustration, and by combining details belonging to different years, with the laudable view of giving all his information in the smallest possible compass. There are so few writers who have sufficient heroism to sacrifice any materials they may chance to have on hand, that we cannot find it in our hearts to censure him for this ; and the want of a more lively and continuous narrative is compensated by his obvious desire to give full and just views of the subjects which he treats. He was actively engaged, for many years, in the commerce between the United States and the northern provinces of Mexico. In the prosecution of this commerce, he has traversed the vast intervening regions, till the incidents of life and travel on the prairies have become familiar to him as his fireside ; perhaps a little more so, as he acknowledges, that it is only in the Far West that he really feels himself at home. His personal adventures, however, were not attended with much peril, and the subject has of late been rendered in some degree familiar by more practised writers. We are much more interested in those portions of the work, in which he gives the results of his observations in New Mexico, and relates the origin and progressof the trade to which we have alluded.

No better illustration could be given of the daring and ever-active enterprise which distinguishes the Americans even more than the race from which they sprang, than is to be found in the history of this over-land commerce with New Mexico. In its conception and general character, it is a revival of the caravan trade of the East. Before it began, that country had depended for its supplies of all commodities other than its own on the ports of Mexico, with which the communications were slow and far from easy. James Pursley, in 1805, was the first American adventurer who found his way across the wilderness to Santa Fé; and the heart of this trading pilgrim must have been as stout as that ascribed by Horace to the navigator who first launched his bark upon the sea ; for it does not appear that he had any other companions than some Indians, whom he encountered on his way. But the same enterprise had been safely accomplished during the preceding year, by a French Creole, named La Lande, who went as the agent of a merchant of Kaskaskia. Neither of these hardy adventurers appears to have returned to tell the story of his perils. Pursley remained in Santa Fé some years ; his subsequent bistory is not known, though there is no reproach resting on his character. But the Frenchman forgot to render an account to his employer, and became a prosperous gentleman with the aid of the capital so dishonestly obtained. Captain, afterwards General, Pike's account of his well known expedition, which was begun in 1806, gave the first impulse to enterprise in this direction. By pursuing the course which he had pointed out, a party found their way, in 1812, to Santa Fé, supposing that Hidalgo's declaration of independence, two years before, had removed the restrictions imposed by the royal government upon the trade; but before they reached their destination, independence was prostrate, and royalism once more in the ascendant ; their goods were confiscated, and they were imprisoned and detained for a long period as spies. Other attempts were subsequently made, some of which were attended with disaster, and some with tolerable success. It is from the year 1822, that Mr. Gregg is disposed to date the real opening of the trade ; wheeled vehicles, the introduction of which gave it an importance it could never otherwise have had, were first employed in 1824.

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