Page:The American Cyclopædia (1879) Volume I.djvu/556

 524 ANIMAL HEAT matter happens to be the most familiar and useful of the artificial means for producing heat, it is by no means the only one which will have that effect. A great variety of both physical and chemical changes, other than oxi- dation, are attended with an elevation of tem- perature, often of a very active kind ; as in the ordinary slaking of lime, where a boiling tem- perature may be reached in a few minutes by the simple combination of water with the al- kali, which already contains the oxygen it is capable of absorbing. A great variety of chem- ical and physical changes are constantly go- ing on in the process of nutrition, varying in their character in the different organs ; and of their details we are in many cases still igno- rant. As we have seen that animal heat is pro- duced as a local phenomenon in the different or- gans, it may be the result of these combined changes, which vary in character in different parts of the body. 2. The first absorption of oxygen by the blood, which takes place in the lungs, is not accompanied by any very marked elevation of temperature. This elevation, if it exist at all, is not sufficient to compensate for the cooling effect of the air and exhalation in the pulmonary cavities ; for we have seen that in the living animal the blood has been found by experiment to lose slightly instead of gain- ing in temperature while passing through the lungs. The oxygen is here taken up by the red blood globules, and thence distributed to the tissues ; but it is doubtful whether its sub- sequent transfer to the ingredients of the tis- sues has any more the character of an active combustion than its first absorption by the blood. Some physiologists regard oxygen as a kind of food which must be supplied to the body with great regularity and constancy, and which is destined to become a constituent part of the tissues very much in the same manner as other nutritive elements. 8. The produc- tion of carbonic acid in the interior of the body is directly due, not to a combination, but to a decomposition of the ingredients of the tissues. Carbonic acid may be generated at any time in either of two ways : by the immediate combi- nation of oxygen with carbon, as in the com- bustion of charcoal ; or by the decomposition of another body still more compound in its na- ture, as in the decomposition of carbonate of lime by an acid, or the decomposition of sugar in fermentation. In both these latter cases carbonic acid is evolved without any direct oxidation taking place ; and the process will go on accordingly without the access of oxygen or atmospheric air. In the animal body it is by such a process of decomposition that car- bonic acid is produced ; and the proof of this is, that if the fresh muscles of a frog, or the living animal itself, be enclosed in an atmosphere of hydrogen or nitrogen, or even in a vacuum, they will still for a considerable period continue to exhale carbonic acid. This has been fully shown by the experiments of Marchand. 4. While it is true that the development of animal ANIMAL MAGNETISM heat is in proportion to the consumption of oxygen and the exhalation of carbonic acid, this is also true of most if not all the other sub- stances consumed and eliminated by the living body. An abundant production of warmth coincides with a general vigor and activity of all the animal functions, with muscular exer- tion, capacity of endurance, and a liberal con- sumption of both the nitrogenous and non- nitrogenous elements of food. We cannot safe- ly attribute the heat-producing power exclusive- ly to one or the other class of alimentary sub- stances ; for while fat and albuminous matters are both consumed in large quantities in cold climates, on the other hand starchy materials form a considerable proportion of the food in warm weather and in tropical climates. In point of fact, oxygen and carbonic acid are two substances which enter and are discharged from the system by the same organ, the lungs ; but there is not necessarily any direct relation between them, except that oxygen is one of the nutritious substances essential to the body, and carbonic acid is excrementitious. ANIMAL MAGNETISM, or Mesmerism, an influ- ence analogous to terrestrial and metallic mag- netism, supposed to reside in animal bodies :m<l to be capable of transmission from one to another. It was first brought into notice in Germany in 1775 by Mesmer, a native of Swa- bia, who had graduated in medicine at Vien- na nine years before, and had written as his inaugural thesis a treatise on "The Influence of the Planets on the Human Body." He regarded the new force, which he said could be exerted by one living organism upon another, as a means of alleviating or curing disease. Maximilian Hell, a professor of astronomy at Vienna, had made some suggestions to Mesmer a few years earlier as to the possibility of pro- ducing an effect on the human body by mag- netism, and he soon claimed to be the discoverer of the new influence. Mesmer declared that the effects he produced were those of animal magnetism, capable of transmission without his touching the body of the patient, while Hell's theory, he affirmed, had made necessary the actual contact of the patient with a metallic magnet. The disputes to which this rivalry gave rise, together with various accusations of imposture, caused Mesmer to receive a warning from the government. He left Vienna, and in 1778 transferred his residence to Paris. Here he appears to have been from the first regarded with dislike, or at least with suspicion, by the medical profession, but with great favor by the general public. He received at his house pa- tients suffering from various diseases, and per- formed upon them many reputed cures by the influence of the magnetic fluid. His method was to seat himself in front of the patient, with his eyes steadily fixed upon him, and to per- form with the hands a few preliminary manipu- lations about the epigastrium and hypochon- drium in order to establish between them what he called the "magnetic relation." He then