"The abstraction of heat must, therefore, be viewed as quite equivalent to a diminution of the vital energy; the resistance opposed by the vital force to external causes of disturbance must diminish, in certain temperatures, in the same ratio in which the tendency of the elements of the body to combine with the oxygen of the air increases."
Secondly. In the situations alluded to, we generally find poisonous and noxious plants, with an abundance of decayed vegetable matter. An English writer has said, "The farmers of England might advantageously employ a million at least of additional laborers in clearing their wide domains of noxious plants,[28] which would amply repay them in the superior quality of their produce. They would then feel the truth of that axiom in philosophy, "that he who can contrive to make two blades of grass, or wholesome grain, grow where one poisonous plant grew before, is a greater benefactor to the human race than all the conquerors or heroes who have ever lived." The noxious plants found in such abundance in the Western States are among the principal causes, either directly or indirectly, of the great mortality among men, horses, cattle, and sheep. The hay would be just as destructive as when in its green state, were it not that, in the process of drying, the volatile and poisonous properties of the buttercup, dandelion, poppy, and hundreds of similar destructive plants found in the hay, evaporate. It is evident that if animals have partaken of such plants, although death in all cases do not immediately follow, there must be a deficiency of vital resistance, or loss of equilibrium, and the animal is in a negative state. It is consequently obvious that when in such a state it is more liable to receive impressions from external agents—in short, is more subject to disease, and this disease may assume a definite form, regulated by location.
Thirdly. A loss of vital resistance may result from drinking impure water. (See Watering, p. 15.) Dr. Graff tells us that "another peculiar appearance, which serves to distinguish these infected spots, is the breaking forth of numerous feeble springs, called oozes, furnishing but a trifling supply of water." Such water is generally considered unwholesome, and will, of course, deprive the system of its vital resistance, if partaken of.
Fourthly. A loss of vital resistance may result from exposure; for it is well known that cattle which have been regularly housed every night have escaped the attacks of this malady, and that when suffered to remain at large, they were frequently seized with it.
Lastly. The indirect causes of milk fever exist in any thing that can for a time prevent the free and full play of any part of the animal functions. The direct causes of death are chemical action, resulting from decomposition, which overcomes the vital principle.
Professor Liebig tells us, that "chemical action is opposed by the vital principle. The results produced depend upon the strength of their respective actions; either an equilibrium of both powers is attained, or the acting body yields to the superior force. If chemical action obtains the ascendency, it acts as a poison."
Remarks.—Let us suppose that one, or a combination of the preceding causes, has operated so as to produce an abnormal state in the system of a cow. She is then suffered to remain in the unhealthy district during the night: while there, exposed to the emanations from the soil, she requires the whole force of her vital energies to ward off chemical decompositions, and prevent encroachment on the various functions. A contest commences between the vital force and chemical action, and, after a hard conflict in their incessant endeavors to overcome each other, the chemical agency obtains the ascendency, and disease of a putrid type (milk fever) is the result. The disease may not immediately be recognized, for the process of decomposition may be insidious; yet the milk and flesh of such an animal may communicate the disease to man and other animals. It is well known that almost any part of animal bodies in a state of putrefaction, such as milk, cheese, muscle, pus, &c., communicate their own state of decomposition to other bodies. Many eminent medical men have lost their lives while dissecting, simply by putrefactive matter coming in contact with a slight wound or puncture. Dr. Graff made numerous experiments on dogs with the flesh, &c., of animals having died of milk sickness. He says, "My trials with the poisoned flesh were, for the most part, made on dogs, which I confined; and I often watched the effect of the poison when administered at regular intervals. In the space of forty-eight hours from the commencement of the administration of either the butter, cheese, or flesh, I have observed unequivocal appearances of their peculiar action, while the appetite remains unimpaired until the expiration of the fourth or fifth day." From the foregoing remarks, the reader will agree with us, that the disease is of a putrid type, and has a definite character. What is the reason of this definite character? All diseases are under the control of the immutable laws of nature. They preserve their identity in the same manner that races of men preserve theirs. Milk sickness of the malignant type luxuriates in the locations referred to, for the same reasons that yellow fever is peculiar to warm climates, and consumption to cold ones; and that different localities have distinct diseases; for example, ship fever, jail fever, &c.
Before disease can attack, and develop itself in the bodies of men or animals, the existing equilibrium of the vital powers must be disturbed; and the most common causes of this disturbance we have already alluded to. In reference to the milk, butter, cheese, &c., of infected animals, and their adaptation to develop disease in man, and in other locations than those referred to, we observe, that when a quantity, however small, of contagious matter is introduced into the stomach, if its antiseptic properties are the least deranged, the original disease (milk sickness) is produced, just as a small quantity of yeast will ferment a whole loaf. The transformation takes place through the medium of the blood, and produces a body identical with, or similar to, the exciting or contagious matter. The quantity of the latter must constantly augment; for the state of change or decomposition which affects one particle of the blood is imparted to others. The time necessary to accomplish it, however, depends on the amount of vital resistance, and of course varies in different animals. In process of time, the whole body becomes affected, and in like manner it is communicated to other individuals; and this may take place by simply respiring the carbonic acid gas, or morbific materials from the lungs, of diseased animals in the infected districts.
We are told that the latent condition of the disease may be discovered by subjecting the suspected animal to a violent degree of exercise. This is a precaution practised by butchers before slaughtering animals in any wise suspected of the poisonous contamination;[29] for according to the intensity of the existing cause, or its dominion over the vital power, it will be seized with tremors, spasms, convulsions, or even death. The reader is, probably, aware that an excess of motion will sometimes cause instant death; for both men and animals, supposed to be in excellent health, are known to die suddenly from excessive labor. In some cases of excess of muscular exertion, the active force in living parts may be entirely destroyed in producing these violent mechanical results: hence we have a loss of equilibrium between voluntary and involuntary motion, and there is not sufficient vitality left to carry on the latter. Professor Liebig says, "A stag may be hunted to death. The condition of metamorphosis into which it has been brought by an enormous consumption both of force and of oxygen continues when all phenomena of motion have ceased, and the flesh becomes uneatable." A perfect equilibrium, therefore, between the consumption of vital force for the supply of waste, protecting the system from encroachments, and for mechanical effects, must exist; the animal is then in health: the contrary is obvious.
Treatment.—The greatest care must be taken to secure the patient good nutritious food, pure air, and water. The food should consist of a mixture of two or more of the following articles, which must be cooked: linseed, parsnips, shorts, carrots, meal, apples, barley, oats, turnips, slippery elm, oil cake, &c. We again remind the reader that no single or compound medicine can be procured that will be suitable for every stage of the disease; it must be treated according to its indications. Yet the following compound, aided by warmth, moisture, and friction, externally, will be found better than any medicine yet known. It consists of