CHAPTER II.

THE EXTENT, OBJECTS, AND IMPERFECTIONS OF PATHOLOGICAL

INVESTIGATIONS.

IN the preceding chapter we endeavored to sketch the general relations of man to the exterior universe, and demonstrate the extent and complexity of his phenomena.

If man be related to celestial and terrestrial bodies-if the existence of man be dependent upon the adjustments of the solar system, the seasons, the climate, the action of the vegetable kingdom, the soil, and upon the great circulation of matter, kept up by the forces of the sun-if the derangement of only one link in this complicated chain of phenomena would result in the destruction of the human race-if the phenomena of man in health be thus complicated, how much more complicated must be the phenomena of disease, when the constitution of the complex solids and fluids of man may be altered in many ways, and the relations between the physical, chemical, vital, and nervous forces, and intellectual and moral faculties may be correspondingly deranged.

In view of the immensity and complexity of physiological and pathological phenomena; in view of the fact, that no single man, even during a long lifetime, is capable of investigating thoroughly the phenomena presented by only one disease, the investigator should always state clearly his views of the extent and bearing of physiological and pathological phenomena, and define the scope and bounds, and methods of his investigations, and candidly acknowledge their omissions and imperfections.

We will now proceed, in a condensed and brief manner, to point out the sources of disease.

1. Astronomical changes are attended by corresponding changes in the phenomena of man. The changes of the day, and month, and year, and seasons are attended by corresponding changes in the constitution and phenomena of man. Not only would derangement of the adjustments of the solar system be attended by corre sponding derangements in the little world of man, but his diseases,

arising from whatever cause or causes, must be influenced by these changes. As the sun with his attendant planets are progressing continuously through space, it is not unreasonable to suppose that the phenomena of man might be modified by the properties and forces of the regions of space through which the solar system travels. That a resisting medium does exist in space, to which the transmission of luminous and thermic vibrations may be referred, has been conclusively demonstrated by astronomers in the case of Encke's comet. What the matter is composing this resisting medium, and whether this matter is uniform, or varies with the dif ferent regions of space, and whether it exerts any influence upon the phenomena of man, are questions worthy of a solution.

Geology teaches that the climate of this earth has been altered during different periods of past times, and that causes have in past times destroyed whole races of plants and animals. Whether these causes were astronomical or terrestrial, it is nevertheless true that similar causes may be the sources of disease.

2. The surrounding medium may be physically and chemically altered, either by an excess or deficiency of its ordinary ingredients, or by an excess or deficiency of the forces by which it is circulated.

Whilst it is true that the amount of force annually received by the earth from the sun is a fixed quantity, it is nevertheless true that, owing to the peculiar constitution of the atmosphere, the nice adjustment of its forces (the ease with which one mode of force may be converted into another, as heat into electricity, and vice versa), its relations to moisture, its relation to the distribution of the forces of the sun, and its relations to the distribution of the solid and fluid. masses of the earth; the climate is subject to variations which cannot be predicted, and are not uniform. Corresponding disturbances are produced in the phenomena of man. The truth of this proposition is conclusively demonstrated by the relations of certain diseases, as pleurisy and pneumonia, to the weather. And even when diseases are not directly produced by the disturbances of the structure and forces of the surrounding medium, it is nevertheless true that the course and phenomena of disease are modified, to a great extent, by meteorological phenomena. The value of the determination of these relations in the investigation of the origin, progress and treatment of disease, cannot be over-estimated.

3. As the compounds composing the body of man have all been formed by the vegetable kingdom, from the inorganic elements, it

follows that any deficiency of the necessary elements of the soil would be attended by deficiencies in the constitution and by composition of the food, elaborated by the vegetable kingdom, and by corresponding disturbances of the constitution and phenomena of man. Corresponding changes in the constitution and phenomena of plants may be induced by meteorological phenomena. Hence, in the investigation of the origin and phenomena of disease, it is necessary to determine the chemical and physical constitution of the soil, and its relations to the vegetable kingdom.

4. The salts of the blood, which are absolutely necessary for its healthy constitution, are obtained in part from the water daily introduced into the system. These salts may exist in deficiency or excess; and other abnormal noxious, saline and organic matters may exist in the water. Each of these causes may be a source of disease. Hence the necessity in pathological investigations of a careful examination of the water.

5. Any one of the normal constituents of the body of man may be deranged, and occupy different relations to each one of the other constituents. As these constituents are numerous, the resulting derangements may be correspondingly numerous. The forms of this class of diseases may be as numerous as the different positions which the elements may be made to assume towards each other.

6. Any one of the elements of his body may be in excess or deficiency, and the diseases may be as numerous as the elements themselves, and at the same time, totally different from the diseases arising from an alteration in the relative position of the ele

ments.

7. Foreign morbific agents may be introduced into the fluids and solids, which will excite abnormal changes in the solids and fluids. The generation of these morbific agents will depend, in great measure, upon the relations of climate and soil, and water and organic matter, and the forces of the sun. The number of diseases of this class will correspond to the number of distinct morbific agents.

Combinations of these morbific agents may produce still more numerous and complicated diseases.

8. As the matter composing the human body is fashioned into definite organs and tissues destined to accomplish definite results, and combined into apparatuses, definitely related to each other, it is evident that the disturbance of the mutual relations of any one of these organs and tissues and apparatus must, to a greater or

lesser extent, produce corresponding disturbances in the component members of the human organism.

9. The Creator has associated the vital force with a definite constitution of matter. Whatever interferes with this constitution, interferes with the action of the vital force. Whatever interferes with the vital force, necessarily disturbs its relations with the physical, chemical, and nervous forces. If the balance of the forces, their correlation be disturbed, the chemical actions between the elements may not only be deranged in kind, but also in degree, and the generation of the physical forces which work the machinery, and the manifestation of the nervous, intellectual and moral phenomena, correspondingly altered.

10. The development and structure of the vegetable kingdomthe development and structure and actions of the most simply constructed animals-the appearance of the nervous system in the animal kingdom, and in the foetus of the higher animals, subsequently to the grouping of the atoms of formless matter into definite forms and apparatuses-the formation of the digestive and circulatory apparatus, before the formation of nervous cells and nervous systems, demonstrate unequivocally, conclusively, and absolutely, that development, nutrition, and the direction of the forces of matter to the fashioning of another part are under the guidance of the vital principle-demonstrate unequivocally, conclusively and absolutely, that the nervous system is itself developed and its perfection maintained under the guidance of the vital principle. Hence diseases may arise independently of the nervous. system. Hence we may have chemical and physical changes of the elements of all the organs and systems of organs, incompatible with the existence of the vital force in that altered matter.

Whilst we admit these propositions, we must at the same time bear in mind the true offices of the nervous system. The nervous system is the last and best work of the forces of matter directed by the vital force, and is destined to form the medium of communication between the intellectual faculties and the exterior world; and is destined to connect together and influence the various organs and apparatuses; and is destined to regulate secretion and excretion, and the consequent development of force; and is destined to excite and control the actions of the dynamic muscular apparatus, not by the possession and emission of a peculiar force generated de novo, but rather by a modification of physical force generated by the mutual chemical reactions of the blood and nervous systems.

That the nervous force is not capable of itself of carrying on the acts of nutrition, secretion and excretion, is conclusively demonstrated by the fact that plants, and the simply constructed animals, which are devoid of a nervous system, are capable of carrying on the offices of generation, development, digestion, assimilation, nutrition, secretion, excretion, and of preserving a definite form amidst unceasing chemical changes. Many of the simply organized animals, although without a nervous system, still possess sensation and voluntary motion. The nervous system appears only when the parts of the machinery are complicated, and need special means of communication.

The development and perfection of the nervous system correspond exactly to the development, perfection and complication of the organs and apparatus. This fact is true of the animal kingdom, in its successive degrees of development, and also of the successive stages of the development of the solids and fluids of each individual highly organized animal. Physical and chemical actions take place in a similar manner in all animals, simple or complex; they differ only in intensity. The higher the animal, the more complicated its parts, the more rapid the chemical changes, and consequent generation of the forces, and the greater is the necessity for some special apparatus which will bring all the complex organs and apparatus and actions into harmonious relation.

Unless the actions of different organs can be telegraphed (so to speak) to each other, confusion in a complicated organism will necessarily result. Thus, if the amount of blood circulating through any organ and the chemical actions are too great, how can they be regulated without some medium of communication, and some means of regulating the chemical and physical actions.

7

The observations and experiments of Rufus Ephesus,' Galen,2 Piccolhomini, Riolan, Plempius," Wills, Chirac, Winslow, Bohn," Duverney, Vieussens, Schrader, Valsalva, Morgagni, Baglivi, Con

1 Appellationes, Part. Hum. Corp. Græcé. Parisiis, 1554, p. 32.

2 Galeni Opera. Venetiis, apud Juntas, 1576, de Hippocr. et Plat. decretus, lib. ii. cap. vi. p. 238.

3 Anatomicæ Prælectiones Archang. Piccolhomini, Romæ, 1586.

4 Opera Anatomica. Lutetiæ Parisiorum, 1649.

5 Fundamenta Medicinæ. Lovanii, 1644.

6 Opera Omnia, edente Balsio. 1682, tom. i. Nervorum Descriptio.

7 Circulus Anatom. Physiol. Lipsiæ, 1697.

8 Treatise on the Heart, Toulouse, 1715.