tion of each to, and its action on all the rest, is no less so. This subject, however, belongs to the last question in the series we have proposed, and hence will be deferred for the present. But while alluding to the agent or agents that excite and maintain the organs in action, we ought not to pass unnoticed the opinions recently advanced by Dr. Metcalfe, in his elaborate work on caloric. In this work, the author has bestowed a vast amount of labor and great ingenuity, in endeavoring to show that caloric is not only the great and only motor power of the physical world, but also the grand primary cause of all vital phenomena. Thus, he says, "caloric is not only the most potent and universal stimulant in nature, but the cause of stimulability" that is, if we comprehend the author's meaning, caloric is not only a stimulant of the organic actions, but is itself the cause of the susceptibility of the organs and tissues to the impressions of stimuli. Again, he says, "if the quantity of life throughout the earth be in proportion to the heating power of the sun, what is the use of animal heat? Is it not the essential character of a vera causa, that its power should be proportional to the effects it produces, and that the latter should cease in its absence? Or if an immaterial and unknown principle of life be still admitted, will it explain anything in the absence of caloric?" And again, in speaking of the symptoms of fever, Dr. Metcalfe says, "that the primary cause of these and all the other symptoms, is a loss or deficient supply of caloric, the animating principle, and a consequent vitiated state of the blood." "In short," says an able reviewer, "Dr. Metcalfe has shown that the anima mundi of the Romans, the archeus of Paracelsus, the materia subtilis of Descartes, the pneumatical body of Bacon, the unknown æther or spirit of Newton, the nervous fluid of Willis, Bær. haave, and Cullen, the materia vitæ of Hunter, and the electric fluid of modern times, are only so many different names of one and the same active principle that produces all the transformations of matter, in accordance with unchangeable laws, and under the guidance of Eternal Wisdom-a principle familiarly known under the name of heat or caloric." It may be thought presumptuous in us, to attempt to call in question the correctness of one of the fundamental doctrines of a work, which has been so uniformly eulogized by reviewers both in England and America. But it seems to us that many positions assumed by Dr. Metcalfe are diametrically opposed to each other, while he is not altogether free from the common error of calling mere effects and coincidences, causes. Thus, in the first quotation already made, we have caloric presented both as a powerful stimulant, and the cause of "stimulability" or susceptibility to the impression of stimulants. Hence the organic actions or functions are the result of caloric, a material body, stimulating itself-a self-evident absurdity. On page of the second volume, we are told by our author, in answer to the inquiry, "Why the cold stage of fever comes on so generally in the forenoon," that "the solution of these queries will be found in the fact, that respiration is always very much diminished during the night, and arrives at the minimum about midnight, when all the energies of life are proportionably reduced; so that as the coldest part of the twenty-four hours is just before sunrise, if the body be not well covered, or its temperature maintained by artificial warmth, the chill comes on at an early hour, or sometimes before midday.” Again, on page of the same volume, we find the following, viz. : "The proximate cause of sleep is an expenditure of the substance and vital energy of the brain, nerves, and voluntary muscles, beyond what they receive when awake; and the specific office of sleep is the restoration of what has been wasted by exercise." If we compare these two paragraphs with the third quotation, we have made from the work of Dr. Metcalfe, it will show the following result: 1st. A loss or deficient supply of caloric, the animating or vitalizing principle, is the primary cause of the cold stage and all the other symptoms of fever. 2d. The reason why these symptoms so generally commence with chills in the morning, is, because the "respiration is always very much diminished during the night, and all the energies of life proportionably reduced." 3d. An expenditure of the vital energies during the day is the proximate cause of sleep; the "specific office" of which is to restore such expenditure. The English language could scarcely furnish two statements more at variance with each other; and yet there are many such in the work under consideration. But it is our present intention to notice the views of Dr. Metcalfe, only in relation to the agents which excite or maintain the healthy action of our organs. This office, as we have already seen, our author ascribes exclusively to caloric; not even allowing oxygen to participate in any other manner than to aid in developing caloric by uniting with carbon in the lungs. That a quantity of caloric sufficient to maintain a certain degree of temperature, is essential to the existence of life, we have no doubt; but that caloric is the exclusive cause of life, and the great stimulant of all vital action, we by no means admit. Indeed, Dr. Metcalfe himself contends, that animal heat is derived from caloric generated by the union of oxygen with carbon and hydrogen during the process of respiration; if so, nothing is more plai than the fact that caloric, so far from being a cause of vital action, and the chief stimulant of all our organs, is a mere result of such action, and the product of one organ. For that which is a product of respiration necessarily supposes the pre-existence not only of a respiratory apparatus, but also such apparatus already in action: hence, instead of caloric being the "animating principle-the universal stimulant," and, therefore, the first in the order of sequence, it is plainly the fourth; for we must first have lungs, next they must be endowed with vitality or a susceptibility to impressions-third, they must be stimulated to action; then, and not until then, do we bring the oxygen of the inspired air in contact with the carbon and hydrogen of the blood, and thereby develop caloric. If there is either order in nature or force in logic, there is no escape from this conclusion. Neither will it aid Dr. Metcalfe, to allege that the foetus is supplied with caloric from the mother before the commencement of respiration; for that will only throw us back on the creation, as recorded in the Book of Genesis. And here we are happily enlightened by the comments of our author himself. For on page 484, he says, "that when it is said God 'breathed into the nostrils of man the breath of life, and man became a living soul,' we can understand only that man was created with breathing organs, for the purpose of obtaining life from the atmosphere." Here our author not only admits that life, or what he makes synonymous with it-caloric-is a product of respiration, but expressly states that it comes "from the atmosphere." But breathing is the act of a living being; hence life must precede breath, and breath precede the development of caloric or animal heat, according to the philosophy of Dr. Metcalfe himself. Neither are his arguments derived from the agency of caloric in the germination of seeds and the greater prevalence of vegetable and animal life in the warmest parts of the earth, more sound. He makes "solar caloric cause the germination of seeds, the growth of plants, and all the vital transformations of the vegetable world." We think it would trouble him, however, to make a seed germinate by the application of any degree of caloric, without the presence of both air or oxygen and water. And if the presence and influence of all these agents or substances are equally essential, what right has Dr. Metcalfe to single out caloric as the cause, in preference to either of the others. And so far is the hottest part of the earth from being the most productive of vegetable and animal life, that no part of the globe, except the polar circles, is more thinly populated, or more destitute of vegetation, than a great part of the torrid zone. Now, it is a sound axiom in philosophy, which should ever be borne in mind, that where the presence of two, three, or more substances are absolutely essential to the existence of a body in its natural and healthy condition, no one of them can be separated out and assigned as the cause of such existence. For the plain reason that whatever is the result of the combined influence of two or more agents, cannot be considered as the result of one of them. Hence, so far is caloric from being "the universal stimulant and the cause of stimulability" throughout all animate nature, that not a living organized being can exist without the presence and influence of at least two other substances, viz.: atmospheric air or oxygen and water. And we might with just as much propriety deprive an animal of life, by placing it in vacuo, or abstracting from it all its water, and then claim that air or water was the animating, vitalizing principle; as to plunge a man into a bath of mercury at 30° below zero, and because death was immediate, infer that caloric was the principle of life- —as done by Dr. Metcalfe. Indeed, we suppose life would be extinguished quite as soon by plunging a man in a bath of mercury, at a temperature of 662° above zero, as 30° below. And if the latter experiment proves that caloric is the life-supporting agent, the former must prove it equally the life-destroying agent. But if Dr. Metcalfe has committed the not-uncommon error of reasoning in a circle, by making animal heat at once the cause and the product of vital action, he is equally unfortunate in his explanation of its agency in disease. As will be seen by a quotation already made, he makes a "loss or deficient supply of caloric" the cause of all the symptoms of the first or cold stage of fever, and consequently, also, the cause of the "vitiated state of the blood." According to this sentiment, the chain of causation would run in this wise. What is the cause of fever? A. A loss or defi. cient supply of caloric. What causes the loss or deficient supply of caloric ? A. A diminution of respiration or vitiated state of the blood. What diminishes respiration or vitiates the blood? A. A loss or deficient supply of caloric. If this last answer is denied, for the purpose of avoiding the argumentum ad circulum, then, the author's whole doctrine, concerning caloric as a cause of disease, is denied also. For the moment we admit the disturbed respiration and the vitiated state of the blood to precede the loss or diminished supply of caloric, that moment we make these the primary cause of the febrile phenomena, and the loss of caloric only a result or effect. The truth is, that, after all our generalizations and our most rigid scrutiny, there is in all animate nature a prima causa, an inherent condition of organization that forms a link, a step anterior to, and beyond, human explanation. It is this first link or condition of organization that renders organized matter susceptible to the influence or stimulus alike of caloric, oxygen, electricity, and all other physical agents. And every attempt to change the order of sequence so as to make any one or all of these agents the cause of this primary condition, which we term vitality, inevitably involves the author of the attempt in endless contradictions and absurdities. And though Dr. Metcalfe has invested caloric with many new attributes, and in fact made it swallow up electricity and all the other so-called imponderable agents, yet he has not escaped the same result. In criticizing thus freely some of the propositions contained in Dr. Metcalfe's work on Caloric, we would by no means be understood as denying that it is a work of great value, and the product of a highlycultivated and investigating mind. We come back, then, to the position, that all animate matter is possessed of a principle of vitality or an essential condition of organization, by which it is rendered susceptible to the impression of oxygen, caloric, etc., as stimuli; and that the functions of the various organs which make up the human frame are the result of the actions induced by the impression of these physical agents on the organized tissue. The particular changes produced in the organic actions and functions, by alterations in these physical stimuli, will be more properly considered under our third inquiry, viz. Of what morbid changes are our organs susceptible, and what the agents capable of producing those changes? ART. V.—An Address to the Westchester County Medical Society, on TO THE EDITOR,-Dear Sir; The within is an address read before the Peekskill, July 27, 1847. GENTLEMEN, If you have expected from your President to-day a learned treatise on some branch of medical science, you will be disappointed. We all enjoy, in common, the same literary facilities for acquiring medical knowledge, and many of you, probably, improve those facilities much more than I do; for I have an innate want of confidence in the opinions of others, on all doubtful subjects, until all the facts of the case in question are brought within the cognizance of my own senses. This native incredulity will lead to solitary thinking. You will, therefore, not ascribe to arrogance what is justly due to honest confession, but listen with the greater curiosity to the result of my own reflections, during my clinical practice in epidemic fevers. As it is the first object of this address, to illustrate by facts the laws of epidemics, it is necessary to look back in my history to the fall of 1828. At that time a bilious remittent fever prevailed in the eastern part of this town, with peculiarities which I had never before witnessed. There were not less than seventy-five cases on the sick-list at one time. Although this was a marsh or malarial fever, where intermittent had been the endemic of that district, its history will illustrate the laws of epidemics, as clearly as that of any other fever; for it matters not whether malaria, or any other invisible poison be the originating cause. The striking peculiarity of this endemico-epidemic, was an inordinate sensibility or irritability of the bowels, without diarrhoea. Such cathartics as are usually given in bilious fevers, if taken in the morning to operate in the rising stage of the paroxysm, would, by their excessive irritation, almost extinguish life; their effects would imitate all the phenomena of Asiatic cholera, except the extreme collapse. This perplexing attendant appeared to be connected, as a consequence, with a total suspension of, or diminished excretion of bile. In this embarrassing condition, without medical authority at that day, I waited for the extreme height of the paroxysın, generally 10 o'clock at night, after the irritability had been exhausted by the action of fever; then to give a purging dose of calomel with one grain of opium. This would procure a quiet night, gentle perspiration, dark-colored bilious stools, and a clear remission in the morning. Repeating this remedy two or three nights, would dispel all that irritability, so that we might resume our usual laxatives with impunity. In the three following years, there were sporadic cases of the same pathological character, but of greater severity-the paroxysms were more irregular. The gastric irritation was so intense, that the patient, rolling on his bed, would name his sufferings an "inexpressible agony." It was necessary for the physician to sit up at night, to watch for the subsiding stage of fever, that he might give with success his soothing cathartic. During these three years I witnessed two interesting cases of cholera asphyxia, which may be called artificial cases. One was produced by a large dose of Epsom salts, followed the next day by a heavy antimonial emetic; the other was the result of a full dose of calomel given for a diarrhoea, to a man at his usual labor, on the day of intermission of a quartan ague. The article during the first hour, produced excessive vomiting and stools of pure blood; after this, other liquid stools, and terminated fatally in sixteen hours. I saw both cases, as counsel, in the state of collapse with icy-cold, and bluish-colored skin. Next year I saw a perfect likeness of these two cases, called Asiatic cholera, in the Park hospital of New York. You will observe I have proceeded in my history through the four years immediately preceding the epidemic cholera, that climax of all locked states of the excretory organs of the liver, and will now stop to suggest a clue to the true pathology of that mighty scourge. In the remittent fever which I have described. it was necessary to improve the hour and minute of the lowest grade of irritability, and add to this circumstance the sootning power of opium, in order to obtain the innate, specific action of calomel on the secretory and excretory organs |