with the enunciation of the theories of Charles Darwin came the most timely scientific awakening that medicine has ever known, because this was a pure science of nature and this is the true goal of medicine.

The discovery of plant and animal cells by Schleiden and Schwann, which now had begun to be utilized, had a far reaching influence in medicine. The laws of physics and chemistry began to be applied to anatomy and physiology, and physiologic chemistry had its birth.

Claude Bernard began his physiological experimentation.

Embryology also came to have a prominent place in medicine, and many structures and organs which previously were not understood were seen to be quite simple when studied from an embryological standpoint of view. Marking another epoch in the development of medicine was the enunciation of the cell doctrine by Virchow and with it the idea of protoplasm as the basis of all living substance. The cell became the morphological unit and the life of the individual depended upon its activity. The far reaching influence of this discovery can scarcely be estimated. The gist of his cellular pathology was that all cells, whether physiological or pathological, arose from a pre-existing cell, thus he proved the origin of the morbid cells from the normal ones and put disease, in some respects, upon an entirely new basis. This gave a great impulse to the use of the microscope which has done so much for medicine. Nothing could be more conducive to exactness in medicine than to be able to correlate the symptoms of a disease with the microscopical as well as the gross findings after death.

One of the most valuable contribution to scientific medicine was the work of Pasteur. Laboring to determine the cause of fermentation in wines he found it to be due to a minute vegetable organism which he called bacteria, the action of which caused the splitting up of the sugar into C O 2 and alcohol. He therefore formulated the law that fermentative and putrefactive processes were due to bacteria and that three conditions were necessary for these processes to take place i. e., the presence of bacteria, moisture and a certain degree of warmth and that by the exclusion of any one of these the process could be prevented.

In connection with this work he also exploded the theory of spontaneous generation. Next solving the problem of the silk worm diseases. which were threatening the silk industry of Southern Europe, by proving that each was due to a specific germ-one protozoan and the other bacterial-he then investigated several human diseases such as septicemia, puerperal fever, and rabies as well as chicken cholera, etc. It was however left to Robert Koch and others to actually isolate and demonstrate the germs. Pasteur went further than this, however, and invaded the field. of immunity. He found that by innoculating chickens with a culture of chicken cholera germs, which were old and attenuated, that the fowls not only did not develop the disease, but were later found to be immune

to ordinarily fatal doses of the culture. He employed this same principle in his investigation of hydrophobia; the spinal cord of an animal afflicted with rabies emulsified and injected into a susceptible animal will invarjably cause hydrophobia, but he found that by attenuating them by drying for varying periods of time, then beginning with the most attenuated and graduating them up to the least, so he could produce a positive immunity. Thus was established one of the principles of immunity, which probably promises more than all else in the world to minimize human suffering.

The problem of infectious diseases is so broad and their manifestations so protean that it is difficult to know how to approach the subject. First let us notice that pathogenic or disease producing germs are of two principal varieties, i. e., vegetable micro-organisms-bacteria or fungi and animal micro-organisms or protozoa-as well as certain other low forms of animal life; next, how do these germs affect the living body?

First, as the itch-mite, by burrowing beneath the epidermis and causing mechancial irritation as well as inflamatory reaction by its poisonous excretions.

Second, by the loss of blood caused by some intestinal parasites, which often leads to grave anemias, such as the ankylastoma-duodenale.

Third, a certain nematode, filaria-sanguinis horminis, by mechanically blocking the lymph-chamuls; and elaborating a toxine which produced the disease known as "sleeping sickness." The plasmodium of malaria cause anemia, by distruction of blood cells as well as febrile disturbances by their toxines. The bacteria produce disturbances both in a mechanical and toxic way-however, the toxic element is considered. more and more the real cause.

Baterial intoxications are of two classes, those due to a soluable toxin excreted by the bacteria, and intra-cellular toxins or those situated within the bodies of the bacteria themselves and probably not eliminated until the death of the bacterium.

Koch's laws, which are quite generally accepted to prove the specific cause of a disease, are as follows: First, the suspected organism must be constantly found in the proper tissues of an animal suffering from the disease, or which has died from it; Second, the organism must be cultivated artificially in a pure state; Third, it must be possible to reproduce the disease in a suitable animal by inoculation with the pure culture; Fourth, the organism must again be cultivated in a pure state from the tissues of the experiment animal.

However, we are not always able to apply each of these laws, because certain germs have not been successfully grown on artificial media; others are not toxic for the lower animals, upon which we must experiment, or do not produce the same symptoms in lower animals.

The following diseases however, have had their germs isolated:

Diptheria, tetanus, typhoid fever, cholera, anthrax, tuberculosis, leprosy, plague, dysentery, influenza, glanders, chancroid, recurrent fever, gonorrhea, epidemic cerebro-spinal meningitis, actinomycosis, blastomycosis, malaria, tick or mountain fever. There are many others in which evidences enough has not been collected that their specific nature can be proven, yet may be placed in the same group from analogy.

Now having proven the specific nature of a disease, how shall we proceed to prevent it, or minimize its effects? This is the problem of immunity.

There are two kinds of immunity; natural and acquired-it is well known that many animals and some persons are wholly insusceptible to diseases to which others readily succumb-they must possess some substance which the others lack, else they must lack some substance which the others possess. The nature of this process is not well understood. It is supposed however, that the cells of the body secrete some substance which either neutralize the toxin of the germ or else has a destructive influence upon the germ itself.

Now can we not help the system to elaborate these materials (active immunity) or cause them to be elaborated by other animals and injected into the system of the individual (passive immunity)? This has been done to a considerable extent, notably in diphtheria and tetanus, but the principal obstacle lies in the fact that only a small number of germs excrete this soluable toxin, their products being much more complex, and located within the germs themselves, therefore, the process of immunization is much more complicated, requiring as it were a cytolytic or cell destroying substance. A cytolytic is supposed to require two bodies the ones which actually destroy the foreign cell are normally present, but it seems incapable of action without the inter-mediation of another body, which is produced by the immunizing action. The first is called the intermediary body, the second, the complement. The production of this body in sufficient quantity is a goal to which we aspire.

The system is stimulated to the production of this body in some instances by the injection of minimal amounts or of attenuated forms of the virus or the dead germs themselves. Much work is being done along this line and there are some hopeful promises, though as yet, except for the antitoxic group, it is principally still in the experimental stage.

In this connection also, we may consider antisepsis and asepsis, which have made the surgery of today possible, a condition undreamed of fifty years ago. About that time a noted surgeon so discouraged by the poor results obtained in brain surgery, wrote an inscription in the forehead of a skull: "Abandon hope, all ye who enter here."

It is now recognized that all infection comes from without and if we can exclude it by rules of asepsis and antisepsis, there will be no sup

puration. This is, however, as Shakespeare would say: "A consummation devoutly to be wished."

We may mention here also the part played by intermediary hosts, such as that of the mosquito in transmitting diseases, such as malaria, yellow fever and filariasis. It has shown that when these intermediary hosts can be positively excluded, there is no transmission of the diseases from man to man and these once dreaded perils will soon be things of the past we hope.

Turning now to the subject of the secretions of the ductless glands, which until recently have been little, if at all understood, it has been discovered that certain glands, such as the thyroid, the suprarenals, the pituitary body, the pancreas, the spleen, the ovaries and the testes, elaborate substances which are returned to the blood and in a way, which is but imperfectly understood, effect the metabolic processes of the body; the absence or perversion of these secretions often have a very profound effect on the organism. Thus, removal or suspension of the function of the thyroid gland, reduces the individual to a state recognized as myxoedema or cretinism characterized by a mental and physical stunting of the individual, and this condition can be overcome by the internal administration of the thyroid gland of lower animals.

As a result of the work in physiological chemistry, the various secretion and excretions of the body are now quite well understood as well as the composition of the normal fluids of the body, and in the absence or reduction of any one of these elements, the effort is made to supply it artificially, else to stimulate the system to its formation; and if this can not be done, as may be the case, with digestive ferments, then the elements of diet which require these substances are omitted and much damage prevented. Infants deprived of their natural food can now be fed on other foods so modified as to imitate the mother's milk and the deathrate thereby much diminished.

A great impetus was given to the study of nervous and mental diseases by the introduction of the neurone theory, by which is meant the unit of the nervous system is a neurone, that is a cell composed of a cell body with its nucleus and two varieties of processes; one class, of which there may be a great number, are called dendrites, and are centripetal in their function, that is, bring in impulses to the cell body; the other a single branching process known as the axone or axis-cylinder process is centrifugal in its function. It is supposed by the majority that these neurones have no protoplasmic continuity with each other or with any other substance.

By the study of these, reflex actions have come to be understood and their relation to the so-called higher psychical centres, which, thanks to the phychologist, has also come to be considered reflex.

Mental disease which was once considered so mysterious, is now con

sidered to be nothing more nor less than a disease of the brain, whereby its function is perverted or suspended and the individual is put out of harmony with his environment.

The department of hematology has also been a great addition to medicine. The leucocytes and red-blood-corpuscles are counted, the size, shape and abnormal qualities noted, especially the various forms of leucocytes, which have a great deal of significance in disease, both as to diagnosis and prognosis. The hemoglobin is measured and its relationship to the number of red-corpuscles noted, this being of much importance in various forms of anemia. We have the interior of the kidney held up to us in a mirror by chemical and miscroscopical examination of the urine.

There is a growing tendency to accuracy and a more truly scientific spirit is gradually pervading the ranks.

The day of the shot-gun prescription is passing, omnibus terms are becoming unpopular and it is demanded that a physician shall have a reason for every dose of medicine he gives. I do not believe with Professor Lee, that we shall soon triumph to the extent of ridding the world of disease germs, in fact, many people would not know what to do with

out them.

Our philanthropists are coming to see the great field that is open to medical research and are nobly responding to the calls. Thanks to preventive medicine, the great scourges which once swept the country, in some instances almost depopulating them, are almost a thing of the past. Thanks to the biologists our understanding of heredity and kindred subjects are becoming clearer and many ills from that source are prevented.

Throughout this brief review of the infant science "medicine-" I believe we have observed two contending forces empericism and science; and at times it has seemed that the former predominated, but in the end this is not true.

True science must prevail and the more closely we adhere to these principles, regardless of apparent results, the sooner will we reach that medical Utopia of which we all dream.

MEDICAL ETHICS

*By F. E. Waxham, M. D., Denver, Colo.

If the millenium were only here and we were all so perfect that each and every one would practice the "Golden Rule" in fact and not in theory, and not adopt old David Harum's version of it, "Do unto the

*Read before the Scientific Society of the University of Colorado.