Billeder på siden
PDF
ePub

the conventional habits belonging to the external order of things, to give and mingle itself with that order which pertains to the higher life.”

We begin with instinct; the end is omniscience. It is a direct beholding; what Schelling denominates a realization of the identity of subject and object in the individual, which blends him with that identity of subject and object called Deity; so that, transported out of himself, so to speak, he thinks divine thoughts, views all things from their highest point of view, and to use an expression of Emerson, “becomes recipient of the soul of the world." Plato himself expressed the idea more concisely. “The light and spirit of the Deity are as wings to the soul, raising it into communion with himself and above the earth, with which the mind of man is wrone to bemire itself." "To be like God is to be holy, just, and wise. This is the end for which man was born, and should be his aim in the pursuit of knowledge.

As might be expected of the persons holding so refined a system of doctrine, their characters corresponded with it most beautifully. It is well depicted in this language of M. Matter, in his Treatise on Gnosticism :

“ The morality which the Gnosis prescribed for man answered perfectly to his condition. To supply the body with what it needs, and to restrict it in everything superAnons ; to nourish the spirit with whatever can enlighten it, strengthen it, and render it like God, of whom it is the image; to make it one with God, of whom it is an emanation—this is that inorality. It is that of Platonism, and it is that of Christianity.”

Whatever the apparent demerits of the Philaletheian doc trines, there must be general approval of the great underlying ideas of Human Brotherhood and perfectibility. Their proper aim was the complete establishment of the rule of peace on earth, instead of that dominion of the sword which had served in former ages, and was destined, in subsequent centuries, to array millions of human beings in mortal warfare against each other, and depopulate countries and districts in the name of religion.

Animal Heat.

BY J. M. F. BROWNE, A. M., M. D. Professor of Physiology and Pathology in the Eclectic Medical College of New York.

WARM-BLOODED animals have the faculty of generating, and of maintaining within them a certain degree of heat, whatever may be the temperature of the atmosphere around them. This power is particularly curious and wonderful. It enables animals to resist extremes of heat and cold without any material change in the temperature of their bodies. The caloric thus generated is called vital, or animal heat. In the human body it is about 98° Fahr., and is the same at all seasons and in every variety of cold. In man the calorifying power is greater than in most animals. He can live, and even enjoy life, both in the polar regions, where the thermometer often falls 100 degrees below the freezing point, and in the equatorial regions, where it not unfrequently rises to 100 de. grees above that point. And for a short period, liis power to resist extremes is greatly beyond what these numbers would indicate. The late Sir F. Chantrey, the sculptor, was accustomed to enter a furnace, where his moulds were dried, when the floor was red-hot, and the thermometer indicated a temperature of 320 to 350 degrees. And Chabert, "the fire-king,” entered, with impunity, an oven, the heat of which was nearly 600 degrees; and in these cases, when water was boiled and meat cooked to a crisp, the heat of the body was but slightly increased.

But this calorifying power does not belong to animals alone. It exists in vegetables also, but in a minor degree. It is a chemical axiom that, whenever gaseous products are liberated, more or less caloric is always evolved. Now, as vegetables respire (or give off oxygen), they must necessarily evolve caloric. But their proper heat is so rapidly dissipated by radiation and evaporation, that it is generally imperceptible by ordinary means. Under some circumstances, however, it may accumulate to such an extent as to be easily appreciable: In the process of malting, for example, and in germination and flowering, there is a well-marked elevation of temperature. A piece of ice placed on a growing leaf-bud will dissolve, when it would remain unchanged in the open air. The flower of a geranium was found, by experiment, to be 6 degrees, and a heap of germinating barley 29 degrees warmer than the surrounding air; and a

66 thermometer placed in the centre of a clump of blossoms of Arum Cordifolium, has been seen to rise to 111, and even to 121 degrees, while the temperature of the external air was only 66 degrees.

Vegetables therefore, as well as animals, possess the power of generating heat. But it is with that power as it exists in animals, that we have at present to do.

To what is the faculty under discussion due? in other words, what is the source of vital or animal heat? To account for this heat, niuch speculation has been indulged and various theories advanced. Once it was believed that the heart was the great furnace of the system, and that the crimson cnrrents that flow from it at every pulsation, went forth freighted with caloric for the warmth of every part of the body. By and by, however, it was discovered that in respiration, as in combustion, oxygen is absorbed and carbonic acid produced; and it was immediately conjectured that respiration was a species of combustion, and was the cause or source of animal heat. The heart theory was dropped, and the lungs were regarded as the heat-producing power of the system. This was Lavoisier's theory. He regarded the lungs as a kind of furnace or stove by which the body is warmed, through the medium of the blood. According to him, the oxygen inhaled united at once with the carbon of the pulmonary tissues, and is immediately returned to the atmosphere under the form of carbonic acid.

But against this theory grave objections were urged. How is it, it was asked, that the lungs, if they are the heatproducing power of the system, are not hotter than other parts of the body? And to this question no satisfactory answer could be given. Further investigation led to the discovery, that the oxygen of the inspired air does not combine

with carbon in the lungs, but is taken up in solution by the corpuscles of the blood, and thus carried off by the current of the general circulation; and that carbonic acid is not formed in the lungs at all, but in the capillaries of the various tissues of the body.

Another theory was proposed by Liebig; it was Lavoisier's theory, with certain modifications. Liebig believed that the heat of the body is produced by the oxidation or combustion of the saccharine, starchy, and fatty elements of the food, while still circulating in the blood. He therefore divided alimentary subtances into two classes: one, which he called the nitrogenized, or plastic elements, which go to build up the tissues; the other the respiratory elements, which farnish the system with heat. The latter, that is, the respiratory elements, or hydro carbons, le regarded as so much fuel, and maintained that they are not assimilated, that they take no part in the function of nutrition—that they are taken into the blood for the sole purpose of being oxidized or buined, and are destined simply to furnish the system with heat.

This theory of Liebig's for a time was accepted by physiologists as the best that had been proposed, but within a few years its errors and deficiencies were pointed out by Lehinan in Germany, and Robin and Verdeil in France; and since then it has been very generally abandoned.

Another theory is, that animal heat is either produced by, & is dependent upon, the nervous system. This view is founded on a few experiments of Brodie, who kept up artificial respiration in animals he had decapitated, and found that, al. though the usual changes took place in the blood and in the air introduced into the lungs, the temperature fell more rapidly than in another animal killed at the same time, and in which respiration was not kept up. But these experiments are far from being conclusive. The nervous system undoubtedly has some influence or control over calorification, but it is certainly neither the source nor the efficient cause of it. The heat-producing power, it will be remembered, is common to animals and vegetables. This fact is highly important, because it " indicates unequivocally that the source of ani

mal heat must be sought for in the organic functions, and not in the functions of animal life. The fact that any change takes place in vegetables to the same degree (under certain conditions) with that in which it is ever present in animals, is a sufficient proof that that change cannot be dependent upon, although it may be influenced by, nervous energy."

What then is the true theory of calorification ? and how is animal heat produced ?

It may be laid down as an axiom, that all molecular movements which cause a change of state, are attended with a change of temperature. We see this exemplified in combustion, which is simply the union of oxygen and carbon, and the consequent production of carbonic acid'; and we see it exemplified in the mingling of liquids that chemically unite. Now, in all the processes of nutrition, these molecular changes are constantly going on; and it is to these changes, and to the various metamorphoses of the tissues, that the faculty of calorification is due. Animal heat, then, results from the various histogenetic molecular changes that food undergoes in forming the blood and building up the tissues ; and also from the hystolytic molecular changes of the tissues themselves. Every change through which the aliment passes from the moment it enters the stomach until it is elaborated into building material for the tissues, is attended with the production of heat; and erery change that takes place in the tissues during their disintegration and decomposition, is also attended with the production of heat. In this way sufficient caloric is generated to account for all that is found in the animal body.

52 Bond Street, New York.

Transmissibility of Secondary Syphilis.

BY T, J. WRIGHT, M. D.

THERE was a time when gonorrhæa and syphilis were regarded as one and the same disease, modified by peculiarities of constitution, which gave rise to the development of one

« ForrigeFortsæt »