BY F. VANDERBURGH, M. D.

The popular theory of the Allopathic school of medicine, a theory on which all their calculations of life and health are founded, is, that animal heat is generated by introducing oxygen into the lungs by inspiration; that the process of breathing separates the oxygen of the air from its hydrogen, when the oxygen unites with the blood in the general circulation, and a chemical union of the carbon and oxygen is effected, by which the carbonic acid is expelled from the system through the lungs, and, by means of oxygen thus supplied, animal heat is generated.

This theory is the foundation of their superstructure of life and health. Now, though the teachings of positive truth is the grand means of expelling error, the process is sometimes quickened by the negative argument serving as its pioneer. The reader will be surprised to learn that no experiments have been spared to confirm this theory, and not one of them has pierced the darkness that mantles its birth.

Negatively considered, if the lungs generated heat by means of respiration, it would seem to imply the power to increase or diminish the standard of heat, by multiplying or withholding the number of respirations per minute. But this is not so-no variableness of breathing alters the temperature of the body, while, on the other hand, every man's experience assures him that he generates heat by motion, and that he is soon compelled to breathe fast to cool himself. But in proof of the position we now take, that breathing is a cooling process, we cite for examples the whole animal world, except the genus homo and the genus horse, and these are not exceptions to the law, only to the rule.

The genus homo and the genus horse have a double privilege of refrigeration, while all other animated beings have but one. Many may be surprised to learn that no other beings sweat except men and horses, and hence no other beings can cool themselves, when hot, by perspiration through the skin. The confirmation of this fact is found in the whole range of comparative anatomy, where nature has furnished examples on the most extended scale of magnitude, in the whole animal world, in the largest as well as the smallest of beings.

In all the pachydermata, or thick-skinned animals, except the horse, are found no pores in the skin that exhale heat by perspiration, the envelope on all these animals being only a secreting surface, like others of the internal surface of the body. All the cleft-feet species, including those presenting feet with toes rounded and unprovided with claws, the elephant, rhinoceros, bison, mammoth, mastodon, buffalo, ox, swine, deer, as well as the lion, tiger, bear, wolf, fox, birds, squirrels, dormouse, opossum, racoon, all alike offer the same examples as the dog, that they have no other means of cooling themselves when hot except through the medium of the lungs, by respiration.

The farmer drives his oxen, in the summer heat, with great care, and when they open their mouths and thrust out their tongues, and pant to exhale the heat generated by exercise, if he does not stop their motion, they die with the heat that accumulates within them. His hogs, too, must be driven with more care, and if they are allowed to grow fat in hot weather, they often die, panting, in a state of repose when in the shade.

All these animals, with the exception of the elephant and rhinoceros, are covered with hair and fur, or feathers and down, which vary with the climate.

The fur and down tribe throw off their rich covering at the approach of spring, and revel with their fellows in a summer's sun, and, as the autumn returns, they are refurnished with their furs and down, in anticipation of the winter's frost

In health, these animals have a large deposit of fat beneath the skin-fat is a mixture of two or more ingredients, which differ from each other in consistency-in most instances they are stearine and margarine, along with a liquid oleine; as the weather cools, these oils and fats condense, and as they solidify they become non-conductors of heat, and as the heat accumulates beneath the skin, it generates the delicate furs and down for winter's use; and in the spring, as the temperature rites, the oleine becomes volatile and sheds them again for summer's heat: so that this simple law for the generation of heat, in animal as in vegetable life, is graduated by the fluctuations of the season and the revolutions of time. The familiar example of the dog, who generates his heat at the expense of his substance, as he increases his speed, and, having no pores in his skin, he multiplies his respiration in the ratio of motion, as the only means of keeping himself cool, and having no perspiration to check, he plunges into water with impunity, and returns refreshed, when men and horses, submerged in a similar condition, would suddenly check perspiration, and if they survived the shock, it would be to die with acute or chronic inflammation.

When nature furnishes examples on such an extended scale of operation, for the escape of animal heat, it would seem to deprive the phenomenon of respiration of much of its fictitious value. There are some experiments that have been performed, by introducing foreign bodies into the venous circulation, that are very significant in their results.

When mercury is injected into any part of the general venous system, it is invariably found in the lungs, the lungs being the inevitable outlet for all foreign bodies introduced into the general venous circulation. In conclusion we state, that apart from these experiments and the examples of animal life, the only chemical action which animal life is known to possess, and the only one which is perfectly known and accurately measured, is the excretion of carbonic acid from the lungs, in the form of watery vapor, which carries off with it the surplus heat as the animal system generates it.

Having stated, as we trust, satisfactorily, .that breathing is a cooling process of life, we come next to the consideration of the true and only cause of the generation of heat is man. The analysis of the saliva, gastric juice, chyle and blood, has proved the first process of its formation to be effected by the agency of water; if we now show from whence the water is derived, the chain of testimony will be furnished. Liebig has established all the phenomena of the generation of heat acceptably, but overlooking one of its most important facts, (the proportion of water in the tissues,) he left the mystery as he found it, in its primitive darkness. He had a clear conception of its generation by the decomposition of the tissues of the body and in the same manner as fire is generated by the decomposition of the wood it burns up; and that both are governed by the same law; in short, that the body is consumed, wasted and transformed by the generation of heat, precisely as any other ignited substances, and parts with its heat to surrounding matter as that of any other heated mass; that oxygen in both cases combines with the carbon and hydrogen; in both cases the same product is given out, namely, heat, carbonic acid, and the vapor of water; that its generation is rapid in proportion to the loss of substance by exercise, creating a rapid transmutation of the tissues of the body. So that life is a fire, the body its furnace and the aliments its fuel.

After knowing and saying so much it would seem impossible that so distinguished an author should fall back and seize upon the same errors that were common to his predecessors. If his mind had not been so carefully instructed in the errors of respiration, he would have seen that more oxygen is introduced into the stomach in one minute by a tumbler of pure water, than could be introduced through the medium of the lungs by inspiration (if they could admit it) in several hours.

In ordinary health the average weight of water drunk by a healthy man is about thirty-two ounces per day, while a hard-laboring man will often drink from sixty to seventy ounces per day, the quantity being proportioned to the transmutation of the tissues, by the generation of heat and muscular motion.

In every thirty-two ounces of water, the average daily supply of a healthy man, are found twenty-eight ounces and four-ninths of oxygen. Eight ounces of bread is a low average of daily consumption, and this contains two ounces and a half of water, while four-fifths by weight of animal food is water, and if we calculate one pound of this to be the average weight daily consumed, it will yield fourteen ounces and two-ninths of oxygen, which foots up the account in round numbers to about forty-four ounces of oxygen daily introduced by degrees into the stomach of a healthy man, which is twelve ounces more than the advocates of pulmonary absorption claim to be sufficient to effect the gradual decomposition of all the hydro-carbons and nitrogenized substances that enter the system in the form of food.

Now here is a dilemma. If thirty-two ounces and a half of oxygen were daily introduced into the system through the medium of the lungs, and thirty-two ounces and a half be sufficient to generate animal heat for twenty hours, what conceivable force could restrain the spontaneous combustion of the body, if forty-four ounces should get into the system by some other channel, that had been overlooked. Apart from all these plain, simple, and obvious facts, the experiments by the thermometer repudiate this generation of heat in the lungs, as the standard of heat by this instrument ranges from one-half to three-fourths of a degree higher in the stomach than in the lungs. In this central organ combustion begins by the rapid mutation of water, vegetable and animal food, as they are converted into starch, alcohol, lactic acid and chyme into chyle, where every stage in the process from the development of one substance into the next in order, evolves an accumulating force of animal heat. The chyle is then conveyed into the receptaculum chyli, heated a little above the standard heat of the body and ascends through the thoracic duct, is conducted from thence into the subclavian vein, from thence into the heart, from whence it is driven into the lungs, (just as the sap is driven into the leaves of the tree,) not for the purpose of being heated, for it returns cooled, but for the purpose of excreting the effete matter immediately derived from crude materials, and is then prepared for the general circulation, when, as it returns, it parts with its infinitesimal deposits among the various solids of the body, evolving animal heat in the ratio of .the conversion of fluid into solid matter.

It is now, we trust, very obvious to our readers, how the human system generates its heat. No matter what the temperature of the food may be when taken into the stomach, it is immediately raised to that of the blood. A tumbler of iced water at the temperature of 32 is raised to that of 98 in one-twentieth part of the time that it could be heated to that degree in the blaze of the hottest fire. Now if there was no appointed outlet for this rapid generation of heat, what would become of the animal system? It is plain it could not maintain its standard at 98, but must run at once into fever and from thence into combustion. In order to maintain its average standard of heat at 98, there must be a provisionary arrangement for the escape of the accumulating caloric, and this has been proved to be through the channel of the lungs by expiration.