to the most malignant type, commonly called congestive fever. If all have been alike exposed upon the same small ship, to the same poison, whence this difference? The difficulty and complexity of this problem, arising about a handful of mariners, may be compre hended when we state that, amongst many other things, its solution would demand a knowledge of the previous history of the physical, chemical, physiological, and moral influences of soil, climate, and disease upon the ancestors, and even upon the races; would demand a knowledge of all hereditary tendencies, peculiarities of temperament, and idiosyncrasy; would demand a knowledge of the relative activity and perfection of the individual organs and apparatus, and of the relations of these to each other; would demand a knowledge of the relations of the vital force to the matter of each organ and tissue and apparatus, and to the morbific agent or agents; would demand a knowledge of the action and reaction of the morbific matter upon the different forms of organized structure, and the consequent derangement of the physical, nervous, intellectual, and moral phenomena; would demand a knowledge of the relations of chemical action to the development of the physical and nervous forces, and the action of the intellectual and moral faculties; would demand a knowledge of the correlations of the physical, vital, nervous, intellectual, and moral phenomena; would demand a knowledge of the relations between physiological phenomena and the phenomena of the exterior universe. Every candid man will admit that the solution of such a problem is impossible at the present time, because the facts are wanting; and they will long be wanting, owing to the extreme complexity of the phenomena.

The imperfections of physiological and pathological investigations are placed in a clear light when we reflect that physiologists and pathologists scarcely recognize the relations between the physical, chemical, vital, and nervous forces; are not acquainted with many chemical changes going on in the body; know little or nothing about the origin and offices of some of the most important constituents of the blood, that great source of the materials of structure and chemical change; dispute about the offices of the spleen, supra-renal capsules, thymus and thyroid glands; and possess no absolutely accurate method of analyzing the blood, or of determining the amount and character of the products thrown off from the lungs and skin.

Whilst, therefore, we assert that the knowledge of pathological

phenomena necessarily includes a knowledge of the relations of all the phenomena of the universe, and affirm that the dignity and glory of a science should depend upon the multitude and complexity of its phenomena-whilst we express the hope that the day will come when the science of medicine shall be founded upon the immovable basis of inductive philosophy, and the world be compelled to recognize the truth that the solution of the problems of medicine requires a higher exercise of the reasoning faculties than the solution of the most complicated and difficult problems in physical and chemical science, a higher exercise of the reasoning faculties than the solution of even the grandest problems of astronomy -we would acknowledge that these physiological and pathological investigations which we are about to present are imperfect in many respects, and are merely beginnings in the right direction.

I shall be satisfied if they demonstrate the impossibility of the successful investigation of even the most striking phenomena of disease by a single individual, and lead to unity and concert of action amongst investigators.

СНАРТER III.

THE BLOOD.

Imperfect state of our knowledge of this fluid-Imperfections in our methods of analysis-Importance and difficulty of establishing a standard formula of the constitution of the blood in health-The composition of the blood varies, not only with the class, but with each species of animals, and corresponds with the development of the organs and apparatuses, illustrated by development of the blood and organs of invertebrate and vertebrate animals-Standard of Lehmann, and of Becquerel and Rodier-Importance of establishing the changes of the blood during thirst and starvation-Importance and difficulty of determining the amount of blood in the system.

In the present state of physiological and pathological science, the investigation of the changes of the blood in health and in disease is attended by great labor and numerous difficulties; and from the complexity of the substances, the number and delicacy and complexity of the chemical changes of these substances, and from the

numerous obscure and complex relations of these substances of the blood with the surrounding organs and tissues, and from the great imperfection of the methods and instruments of investigation, absolute accuracy is impossible. In view of the great labor and numerous difficulties and imperfections and absolute failures necessarily arising from the great complexity of the substances and phenomena, and from imperfections in the modes and instruments of investigation, and from the partial and imperfect nature of all the results of investigation thus far recorded, the profession is compelled to view with consideration even approximations to the truth. These statements are dictated neither by a spirit of exaggeration, nor by a desire to avoid criticism or to crave indulgence. They are true, because important questions with reference to the origin and offices of the most important constituents of the blood remain unsettled and involved in obscurity.

Whilst the physiological chemist knows that the elements of the blood are ultimately derived from the inorganic world (one portion directly and the other secondarily through the vegetable kingdom); whilst the chemist is able to investigate all the combinations and relations of these inorganic bodies out of the living organism; whilst the physicist can demonstrate the correlation and establish the mechanical equivalents of the forces generated during these chemical changes; while the physiologist can describe the general process of digestion, and the general superficial changes of the inorganic and organic materials during their preparation for the blood and structures; whilst the physiological chemist can isolate many of the constituents of the blood, and of the secretions formed from the blood; whilst the physiological chemist can isolate many of the substances resulting from the metamorphoses of the tissues and blood, and form plausible hypotheses with reference to the relations of these chemical changes to secretion, nutrition, and the development of the forces-still, the knowledge of the physiological chemist is incomplete, because numerous chemical changes have never been investigated, and his knowledge does not cover sufficient ground to allow the analysis, comparison, and generalization of all the physical, chemical, and physiological actions, or the determination of the origin, development, and metamorphoses, and physical, chemical, and physiological relations of each substance, or the determination of those fixed relations or laws by which it would be possible, not only to explain the correlation of the physical, chemical, vital, and nervous forces, but also predict with abso

lute certainty the effects of disturbances in the chemical changes and in the development and mutual relations of the forces.

The imperfection of physiological and pathological science is placed in a clear light when we consider that the cause of the coagulation of the blood, the most striking and apparently simple phenomenon presented by this fluid, is still undetermined, notwithstanding the researches of Hewson, Hey, Prater, Hunter, Fordyce, Langish, Thackrah, Scudamore, Brücke, and Richardson; when we consider that the mode of origin and offices of fibrin are still matters of dispute, Zimmerman, Simon, and Inman considering it as an excretory product, of no further use in the animal economy, destined to be still further metamorphosed, and finally cast off, whilst Paget, Carpenter, and other physiologists regard it as the most perfect of the nutritious products destined to enter into the constitution of the organs and tissues; when we consider that the mode and place of origin, and the offices, and the mode and place of death and disintegration and excretion of the colored bloodcorpuscles are still subjects of dispute and investigation with the best physiological chemists; when we consider that the mode of the formation of the secretions from the blood, and the connection of the nervous system with secretion, nutrition, and excretion, are undetermined, and are now engaging the attention of the best minds of the profession; when we consider that the series of chemical changes which the elements undergo during the nutrition of the organs and tissues, and during the development of the forces, are very imperfectly understood, if not wholly unknown; when we consider that the physical and chemical relations of the elements of the living body to the vast majority of poisonous compounds are unknown; when we consider that physiological and pathological knowledge extends merely to the time and place, and results of change, and not absolutely to the nature of the changes themselves; when we consider that no definite opinions prevail with reference to the relations of the physical, chemical, and nervous forces and phenomena with the vital and intellectual and moral principles. Should these imperfections in physiological and pathological science cause indolence and indifference? Should the complexity of the phenomena, and the imperfections in the instruments and modes of analysis, lead the honest inquirer after truth to abandon the investigation in despair?

The honest attempts to unravel complicated phenomena, by honest and truth loving minds who are not afraid or ashamed to

point out their failures, and the imperfections of their modes of investigation, and who ardently desire to incite others to investigation, and who would cheerfully destroy with their own hands every erroneous statement or hypothesis or theory which they have promulgated, have been and will often be characterized by the parasites and vultures of the medical profession, as failures, yea, even as dishonest failures, simply because they yield only negative results, or fail to elicit the whole truth.

In judging of the value of original investigations, we should at all times bear in mind the fact, that the development of all sciences has been the slow result of the labors of many minds, and that the rapidity of the development of each branch of knowledge has been in exact proportion to the complexity of the phenomena. Thus mathematics, and astronomy and mechanics, which deal with the most simple and general phenomena, were the first developed, and are now the most perfect of all sciences. As man stands upon a pyramid, the foundation of which is the inorganic world, and the materials composing this pyramid, consisting first of plants in various stages of development, the simpler extending downwards, the more complicated extending upwards, diminishing in numbers as they increase in complexity; and secondly of animals in various stages of development, increasing in complexity and diminishing in numbers as they extend upwards; and as the existence of man is absolutely dependent upon the relations of the component members of the universe; and as the forces of man are all the resultants of the action of the same forces of the sun which keep up a never ending circulation and change of the matter upon the surface of our globe; and as the development and action and life of man and of all organized beings depend upon the forces not only of our sun but also of the fixed stars, it is evident that he is a type of the universe and comprehends within himself all phenomena, astronomical, physical, chemical, physiological and psychological, and that his phenomena are exceedingly complex, and require for their complete solution the most laborious investigations and the most exalted exercise of the reasoning faculties. Notwithstanding, that from the complexity of the phenomena and the difficulties of the investigations, the progress of physiology and pathology must be slow; the observer, so far from being discouraged, should be animated to vigorous and prolonged effort, remembering that every honest physiological and pathological investigation must be productive of good, even if its results be only negative. Negative