SOME NEW CONCEPTIONS OF THE LIVING CELL: ITS CHEMICAL STRUCTURE AND ITS FUNCTIONS.*

BY VICTOR C. VAUGHAN, PH. D., M. D., LL. D., ANN ARBOR, MICHIGAN.

PROFESSOR OF HYGIENE AND PHYSIOLOGICAL CHEMISTRY, DIRECTOR OF THE HYGIENIC LABORATORY, AND DEAN OF THE DEPARTMENT OF MEDICINE AND SURGERY IN THE UNIVERSITY OF MICHIGAN.

Mr. Chancellor, Members of the Faculty, and Students: When I received from my friend, your worthy Dean, an invitation to address you on this occasion, I delayed my reply for some days, during which I seriously debated the question with myself. On the one hand, the memory of previous delightful visits to you and the anticipation of again being with you urged me to accept; while the consciousness that I was not prepared with an address suitable to the occasion, admonished me that the proper thing to do was to decline. However, when I recalled the indulgence with which you had received my former efforts, the decision was reached, and I now have to offer you my best, fully conscious that it is not good enough, and that you will again have opportunity to exercise your charity.

Something more than fifteen years have passed since I had the honor of being the guest of the University of Toronto, and I wish to say that it is with great pleasure that I have today seen the great advance that has been made by this noble institution during that time. I first came here to rejoice with my friend, Professor Ramsay Wright, on the completion of his biological laboratory, and it is a gratification. now to see that this laboratory has more than fulfilled the promises made at that time. The research work of its eminent director, of Professor McCallum, and others, have carried the name of the Univer

*

Opening address before the Medical Department of the University of Toronto, October 4, 1905. Reproduced by courtesy of The Canadian Journal of Medicine and Surgery.

sity of Toronto around the world. I have had great pleasure in going through his new building with Professor Ellis, and in recognizing that a chemist, whatever may be the fate of prophets, is not without honor in his own country.

I also rejoice in your splendid new Medical Building, and I envy the freshman of today, who comes filled with the earnest intention to do his work well, and who, under these favorable conditions, in the wellequipped modern laboratories, with such able masters to direct, begins the study of the beneficent science of medicine. I was greatly rejoiced on reading in the papers this morning of the munificent gifts that have been made for the new university hospital. Surely the people of Toronto are both wise and generous. He who aids in building a hospital, where human suffering may be relieved, is a practical Christian, whatever his theological dogma may be. We know not whence we came, nor can we name the country to which we journey, but we do know that the burdens placed upon the shoulders of those who travel along life's highway are not equally distributed, and he who helps his fellow-man, who is growing faint, serves his God. There is an old legend concerning the origin of the medical profession, which I may, I hope, be permitted to repeat. It runs thus: In the olden days when the world was yet young, a young Hindoo prince, who had all the world could give, entered a temple and, prostrating himself before the image of Buddha, besought his god to instruct him in the ways of righteousHis prayer ended, he felt upon his shoulder a hand as light as that of a child, and a voice as sweet as that of an angel asked, "Wouldst thou most acceptably serve thy God? If this be thy desire, go forth. and serve thy fellow-men," and the prince went forth, the first physician to walk among men.

ness.

My visit is not without its tinge of sadness. I miss several faces that were familiar to this campus fifteen years ago. Of two of these I must be permitted to say a few words. There was a sweet-mannered man, gentle in voice and kind even in reprimand, an eminent ethnologist, an able historian, whose memory has always been to me a charming recollection. Such a man was Sir Daniel Wilson. The other was a professional brother, whose life was a help to those of his own generation and an inspiration to the young. Such a man was the late Doctor Graham, of this city and university.

I have decided to briefly discuss "Some New Conceptions of the Living Cell: Its Chemical Structure and Its Functions." No one can question the importance of this subject, involving, as it does, biological problems, which lie at the foundation of all our conceptions and theories concerning cellular life and cellular activity.

To start ab initio, the cell is made up of matter, and the newer views on matter must be taken into consideration in formulating a conception of the cell. When matter becomes endowed with life it does not cease to be matter; it does not lose its inherent properties; it is not released from the laws that govern its structure, its attractions, and its

motions. In studying the organized cell of living thing, whether vegetable or animal, it should always be borne in mind that it is material in composition and subject to the fundamental laws that govern matter, and possessed of those properties essential to matter. In order that this point, so essential to a proper understanding of the subject, should be thoroughly appreciated, it may be best to recall some of the properties of matter as taught by the most advanced science of the day.

Tait says: "Matter is that which can be perceived by the senses, or is that which can be acted upon by or can exert force." Since force is the result of motion, we may say that anything and everything that moves or can be moved, or whose position in space may be changed is matter. There are many forms of matter that cannot be seen or felt, and can be recognized only by their motions.

Matter is indestructible; it may be successively solid, liquid and gas, but in undergoing these changes it neither gains nor loses. It has always been, and it always will be. It is without beginning and will be without end. Matter consists of infinitely small particles, called atoms. According to the computation of Lord Kelvin, the diameter of an atom is not greater than a 1-50,000,000 of an inch; however, all atoms are not of the same size or weight. When like atoms combine they form chemical elements, of which about seventy are known. The hydrogen atom is the lightest of all known elements, and it therefore is taken. as the base or standard in the determination of atomic weights. When unlike atoms combine, chemical compounds are formed, and the number of these is beyond computation. It was supposed, until the discovery and study of radium, that one chemical element is never converted into another, and consequently that the number of kinds of atoms is fixed and unchangeable. However, it has been found that the x-rays of radium consist of most minute particles, which, when confined in glass, condense and form another element, helium. With this demonstration of the formation of one element from another it is within the range of sanity to suppose that all the elements have been developed from a primordial ancestor, probably from the universal ether which pervades all space. Nothing has been created; everything has grown. Even silver, iron, and other metals came into existence by being cast off from some common ancestral element. The atomic weight of radium is 225 and that of helium 2.02. It would seem from this that an atom of the former breaks up into about one hundred atoms of the latter, and in this way a new element is born, although in this case it is probable that the mother atom is split into two or more kinds. It will be seen from this that even atoms may be split up. Indeed, there are reasons for believing that the hydrogen atom consists of a nuclear ion about which some seven hundred particles or electrons revolve, and an atom of mercury is believed to consist of not less than one hundred thousand electrons. Atoms and electrons are in constant motion, and so small are they that the distances between them may be relatively as great as those between the planets of the solar system. The living

cell is composed of molecules, made up of atoms, composed of electrons. that are in constant and systematic motion, and may be compared to a group of stars with attendant suns, each of which is surrounded by its own planets. A molecule of albumin is of like composition.

Another property of matter is that it is gravitative. Every particle of matter attracts every other particle. When this attraction is manifest between masses it is called gravitation; between molecules, it is called cohesion or adhesion, as the molecules held together are alike or unlike; between atoms it is known as chemical affinity or chemism. Still another property of matter is inertia, by which term we indicate the inability of matter to change either its rate or direction of motion without being acted upon by other matter. It is of great importance that this property of matter be held in mind in the study of cellular chemistry, and the proper mental picture of a cell molecule represents each of the atoms in the molecule, and each electron in each atom moving each about its centre and each at a definite rate. If such a cell molecule could be cut off permanently from the disturbing influence of other matter, its atoms and electrons would continue the same motions, unchanged in direction or rate, throughout eternity, but, as we shall later see, it would be impossible for living matter to continue to live apart from other matter. Within the living cell molecule change in number, kind, and arrangement of atoms is constant; and the direction and rate of the motion of the atoms are also susceptible to the influence of other matter and are of constant occurrence. Whole groups of atoms are physiologically being dropped from the cellular molecule and being replaced by other groups split off from the pabulum upon which the cell feeds. In this way the cell renews itself and keeps itself supplied with energy.

Some of the most noted physicists are inclined to the belief that matter is made up of electric charges, but recognize that this is not a demonstrated fact as yet, and speak with caution. Lodge says: "There may possibly be two different kinds of inertia, which exactly simulate each other, one electrical and the other material; and those who hold this as a reasonable possibility are careful to speak of electrons as 'corpuscles,' meaning charged particles of matter of extremely small size, much smaller than an atom, consisting of a definite electric charge and an unknown material nucleus; which nucleus, as they recognize, but have not yet finally proved, may quite possibly be zero."

The only essential and constant difference between living and nonliving matter is that within the molecules of the former there is constant metabolism, while in the latter no such process occurs. We are to conceive of the living molecule as made up of numerous atoms and each atom surrounded by its electrons: atoms and electrons in ceaseless motion, and groups of atoms being constantly cast out of the molecule and replaced by new groups split off from matter outside the molecule. As soon as a molecule becomes the seat of assimilation and excretion, it is no longer dead, it lives. As a result of assimilation