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did not necessarily appear to be a defective supply of fluids. In the stomach they were often as copious, sometimes more copious, than usual ; and the latter was almost always the case in the lungs. The fault seemed to be, that a due change on them had not been effected. We know that the vessels of circulation possess no powers but the elastic and the muscular, or what in many of its properties resembles the latter. Can we suppose, that the vessels of secretion, which are only a continuation of those of circulation, all at once assume a different nature; or is it at all consistent with our knowledge of the phenomena of chemistry to suppose, that by any influence the powers just mentioned, or indeed any that can be supposed to belong to vessels, could be enabled to separate and re-combine the elementary parts of the blood ? The first of the above positions being set aside, it seems a necessary inference from the experiments referred to, that in the function of secretion, the vessels only convey the fluids to be operated upon by the influence of the nervous system.
It is not to be overlooked, however, that the vessels convey the fluids in a peculiar way. By the lessening capacities of the capillaries, the blood is divided, as by a fine strainer, some of its parts being too gross to enter the smaller vessels. How far the blood may thus be: subdivided we cannot tell. As this structure of the vessels is uniform, we have reason to believe, that its effect on the blood is necessary to prepare it for the due action of the nervous influence.
We are now prepared to consider the question, for what purpose is the influence of the whole nervous system bestowed on the muscles of involuntary motion ? Admitting, it may be said, that the due performance of secretion requires the united power of all parts of the brain and spinal marrow, and that we may therefore explain why their united influence is bestowed on secreting surfaces; the question still remains, why should their united influence be bestowed also on the muscles of involuntary motion ?
It is evident, that affections of the nervous system could produce no occasional increase of the secretions, were not the sanguiferous system, and particularly the vessels of secretion, capable of being stimulated by the same influence which operates in the formation of the secreted fluids. The increase of secreting power in any part would be in vain, were there not at the same time a corresponding increase in the supply of the fluids on which it operates. A similar observation applies to the excretory muscles, as far as they are muscles of involuntary motion. The same increase of nervous influence which occasions an increased flow of secreted fluids, excites these muscles to carry off the increased quantity. Nature does not seem to trust this to the increase of stimulus, occasioned by the increased flow of the secreted fluid, which we have reason to believe from the modus operandi of certain causes of inflammation, would often occasion morbid distention. Now the vascular system, and the muscles of excretion, if in them we include the alimentary canal, comprehend all the muscles which are supplied with ganglionic nerves, unless we regard the iris as a muscle. The state of this organ is quite anomalous in the animal economy, being one of involuntary motions, excited only through the medium of the nervous system.
In the preceding view of the subject, we find the relation of the
vessels of secretion to the nervous system the same as that of the heart and vessels of circulation. Their function is independent of, but capable of being influenced by, this system.
Thus, we perceive, the necessity of every part of the function which the ganglions appear to perform. A combination of the whole nervous influence is necessary to the due formation of the secreted fluids; and that there may be, under all circumstances, both a due supply of the fluids to be acted upon, and a due removal of those prepared, whether for the functions of life, or for the purpose of being thrown out of the system, it is necessary, as appears from what has just been said, that the powers which convey all these fluids should be subjected to the influence by which secretion is performed. This function, it is evident, requires a more regular supply of fluids than could have been obtained, had the usual action of the vessels depended on the nervous system, which is subject to continual variation ; but had not this system been capable of influencing the vessels, not only no change in it could have influenced the flow of secreted fluids, but every occasional increase of the influence of the nervous system, supplied to secreting surfaces, finding no increase of fluids to act upon, would necessarily have excited disease. Thus, it is requisite that the power of the sanguiferous should be independent of the nervous system, yet capable of being influenced by it; as from direct experiment, we have just seen, it is found to be.
The secreting processes are constantly attended with a temperature considerably raised above that of the surrounding medium. Does this also depend on a function of the nervous system?
It appears, from experiments above referred to, that the destruction of any considerable portion of the spinal marrow, deranges the function of secreting surfaces. Together with this effect, it was always found to lessen the temperature of the animal, more or less, according to the extent and importance of the part destroyed. Some years previously, Mr. Brodie, in the Croonian Lecture for 1810, gave an account of experiments which led to the inference, that the maintenance of animal temperature is under the influence of the nervous system, and in the Philosophical Transactions of 1812, he relates additional experiments, tending to strengthen this inference. The experiments related in the inquiry just referred to, seem in a striking manner to confirm the opinion of Mr. Brodie. He found that poisons impairing the vigour of the nervous system, impair the temperature. It appears from my experiments, that lessening the extent of this system, by destroying part of the spinal marrow, has the same effect.
Thus, it follows, that the temperature of the animal body depends on the state of the nervous system; but many observations point out that it depends also on that of the powers of circulation. When the power of the heart and vessels is greatly impaired, so that the motion of the blood languishes, the temperature falls. If by exercise, or the use of stimulants, we increase the action of the heart and vessels, the temperature in the same proportion rises. When there is a natural defect in the organs of circulation, and particularly when this defect is such as prevents the blood passing through the lungs, with the freedom necessary to its healthy state, the temperature is found below the natural standard. The reader may consult a paper on this subject, by Mr. Earle, in the seventh volume of the transactions of the Medico
Chirurgical Society, in which there are many excellent observations, As we proceed, we shall find proofs founded on direct experiments, that the temperature depends on the state of the circulation, and particularly on the passage of the blood through the lungs, which to detail here, would too much anticipate some of the other parts of the subject.
Whether caloric be a substance, or as some of the first chemists of our time are inclined to believe, only a certain motion of the particles of bodies, it is of course foreign to this paper to inquire; but it appears from the foregoing observations, and will, I think, appear still more strikingly from those I shall have occasion to add, that the maintenance of animal temperature must be ranked among the results of the action of the nervous system on the blood. It is on this account that I have elsewhere said, that if caloric be regarded as a substance, its evolution in the animal body must be ranked with the secreting processes; the definition of secretion, I conceive, being the evolution of a tertium quid, in consequence of that action.
When to the functions which have now been detailed, we add, that the nerves are the means of conveying impressions to and from the sensorium, we have, I believe, enumerated the whole of the functions of the nervous system properly so called.
Although it has been very generally admitted, that the nerves of the organs of sense perform no other function but that of conveying to the more central parts of the nervous system the impressions they receive, it has been supposed that the nerves of other parts, and particularly those of the viscera, are capable of so impressing each other, that these parts sympathize independently of the more central parts of the system. This position, which, were it correct, would seem in opposition to many established laws of the nervous system, I have considered at some length in the ninety-sixth and following pages of the second edition of my Treatise on Indigestion. It appears, as far as I can judge, from the facts there adduced, that it is altogether unfounded, the nerves seeming in the latter as in the former case, only to convey impressions made on their extremities to the more central parts of the system.
FROM THE MONTHLY MAGAZINE
Travels in Georgia, Persia, Armenia, Ancient Babylonia, &c. &c.
during the Years 1817, 1818, 1819, and 1820. By Sir Robert Ker Porter.
This is one of the best written, and most elegant books of travels, which, for many years, has issued from the press. The countries visited are deeply instructing from numerous associations, and we have not often had travellers who have had the author's courage to explore their recesses, his ability to describe them, or his pencil to depict their most remarkable objects. He travelled too with the feeling which gratifies the reader's curiosity in regard to the most striking objects, and his descriptions are full, clear, and satisfactory. We may instance his description of the ruins of Babylon, those objects of universal sympathy, and those pictures of what time will render all cities, howeyer great or proud.
A SACRED VILLAGE IN PERSIA.
“At three o'clock in the morning of August 1st, we left the caravansary, and turned our cavalcade into a north-western direction through another narrow valley; bounded on each side by craggy mountains,
which were traversed by the most opposite and varied strata I had ever seen. A stream, equally clear and inviting with those of the Kala-Gul-Aub, flowed by our path, which lay under groves of wild almond, hawthorn, and mulberry-trees, intermixed with large bushes bearing a flower resembling lavender both in appearance and smell. Notwithstanding the vernal luxuriance of such a scene, the road itself was extremely desert and bad, being a continuation of rough, loose stones the whole way from Mayan to Iman Zada Ismael, a journey of three farsangs. This latter village is considered holy ground, and not only shows a general aspect of comfortable means, but an air of civilization seldom met with on this side of Ispahan. Every individual in the place claims his descent froin Mahommed; hence they are all called Saieds, or sons of the prophet. A picturesque old caravansary nearly in ruins, and a high-domed building, are its most conspicuous objects. The hospitality of the natives seems to have rendered the former useless; and the latter, which gives its name to the village, covers the holy relics of the Iman Zada Ismael. Of his particular history nothing is now remembered, but that this is his tomb; the sanctity of which would of itself hallow the ground in its vicinity; therefore this spot has a double claim to reverence, being an abode of the living descendants of the prophet as well as of the dead.
“We were lodged in the house of one of the ten thousand branches of the great holy stock, where the most unexampled attention was shown to our convenience. A principal division of the mansion was cleared entirely of its usual inhabitants, and the vacated apartments, above and below, appropriated to the sole use of ourselves, our people, and our quadrupeds. Every sort of provision that the village afforded was at our command, and due attendance to prepare and serve it. We were surprised by finding the women of the place not only walking about in freedom, but completely unveiled, and mixing promiscuously in discourse or occupation with the male inhabitants ; neither
lid they retreat from their various domestic employments on our near approach. Their features are regular, with dark complexions, and large fine eyes; and their figures are good, with a general appearance of cleanliness, a grace not very common amongst the lower classes in Persia. The chief cause of such humble affluence and manifest content, lies in the sacred village being exempted from tribute of any kind. Neither does it furnish the customary quota of armed men, demanded on the part of government from all less holy districts, to attend the king in his wars or annual encampments; and, in addition to these privileges, the prince-governor of Shirdz pays a yearly sum of forty tomauns towards the repair and decoration of the Iman's tomb. The village is well constructed, clean, and at every point shows a flourishing condition. A large tract of garden-ground, abundantly stocked, and a corresponding space for corn in as favourable cultivation, stretch before the walls. The whole southern face of the mountain, wherever practicable, is clothed with quantities of grapes; and every little sheltered spot rendered some way profitable by these in
dustrious people. They have not the advantage of even a single stream to assist their labours, but are obliged to transport all the water they use, from wells; which increases the toil, and lamentably circumscribes the extent of their cultivation."
THE PERSIAN CHARACTER.
“ The variety of character amongst these people is equally interesting and extraordinary, and that variety does not exist more in certain dissimilarities distinguishing one individual from another, than in those very dissimilarities often' meeting in one man, The Persian's natural disposition is amiable, with quick parts; and on these foundations, the circumstances of climate and government have formed his character. Perhaps a stronger proof could not be given of the former trait, than that we find in their history no terrible details of sanguinary popular tumults. The page is blotted in a thousand places, with massacres done by order of a single tyrant; but never a disposition for insurrection, and wide murderous revenge, in the people en
Fonder of pleasure than ambitious of the sterner prerogatives of power, they seek their chief good in the visions of a fanciful philosophy, or the fervours of a faith which kindles the imagination with the senses. The dreams of their poets, the delights of the Anderoon, the vigour of the chase; these, with services at court, whether to the Shah, or to his princely representatives over provinces, or to their delegated authorities in towns and villages, all alike form the favourite pursuits of the Persian, from the highest khan to the lowest subject in the empire.
"I have already mentioned, that the peculiar temperament of the Persian is lively, imitative, full of imagination, and of that easy nature which we in the west call 'taking the world lightly; and that hence he is prone to seek pleasures, and to enjoy them with his whole heart. Amongst these, the gaiety of his taste renders him fond of pomp and show; but his fear of attracting suspicion to his riches, prevents him exhibiting such signs in his own person, beyond an extra superb shawl, a handsomely hilted dagger, or the peculiar beauty of his kaliouns. The utmost magnificence of his house, consists in the number of apartments, and extent of the courts; of the rose-trees and little fountains in the one, and the fine carpets and nummuds in the other. But vessels of gold or silver are never seen. The dinnertrays are of painted wood; and those on which the sweetmeats and fruits appear, are of copper, thickly tinned over, looking like dirty plate. Neither gluttony nor epicurism is a vice of this nation. The lower classes also live principally upon bread, fruits, and water. The repasts of the higher consist of the simplest fare ; their cookery being devoid of any ingredient to stimulate the appetite. Sherbets, of different kinds, are their usual beverage ; and tea and coffee the luxuries of ceremonious meetings. In this general abstinence from what is usually styled the pleasures of the table, we find a nearer resemblance to the manly frugality of ancient Persis, or Iran, (which the admirable institutions of the first Cyrus extended from that people to the less temperate Medes,) than to the manners which prevailed even in so short a time as a century after, under the reign of Artaxerxes Mnemon.
“ From the earliest times, the breeding of fine horses has been a pas