For convenience in arrangement we may group this survey along the lines of practical applications of service to mankind, such as occur in medicine, agriculture and kindred industries, domestic and social life, and those which have to do with the acquisition of knowledge and with education.
Applications of biology in medical science, in agriculture and in domestic life have in many cases assumed such intimate and essential character that we often look upon them as applied sciences more than in any other way.
While biology has been the foundation of all rational systems of medicine and the constant servant of this most beneficent of human professions, the forms of its uses and the wide reach of its service have so increased in recent years that we almost have excuse in feeling that it is a modern acquisition.
Could the ancient disciples of Esculapius, with their views of physiology and anatomy, have seen the present scope of these subjects and the marvelous results in cure and control of diseases by the discoveries and applications in bacteriology, I doubt if they would have recognized it as any part of their biology. Still harder would it have been to appreciate the relations of malarial parasite, mosquito and man whereby a serious disease in the latter is occasioned. Intimate relations of two kinds of life, as evidenced in the common parasites, must have been familiar from early times and their effects duly recognized, though their means of access and necessary life cycles were long misunderstood. But such relations as are found to exist in the production of malaria, Texas fever and yellow fever have been so recently discovered that we count them among the triumphs of our modern science. Indeed the discovery of such a relationship may be considered as having been impossible until the methods of modern research and the basis of knowledge as to life conditions were acquired, and which made it possible to put the disjointed fragments together. With the fragments thus related the riddle seems so simple that we wonder it was not solved before, but we must remember that it is knowledge which makes knowledge possible.
These direct advantages in medical science are however but part of the great gift to modern methods of disease control, for the possibilities in the control of disease by sanitation, quarantine, vaccination, etc., and other methods are all based on biological data.
In speaking of these recent acquisitions I would not disparage those important, in fact essential subjects of longer growth. Modern medicine would be a fragile structure without its basis of comparative anatomy, physiology, materia medica and therapeutics, which have for long years furnished a basis for rational methods in surgery and medication.
With all this knowledge at hand it is grievous to observe how general the delusion that disease may be eradicated by some much emblazoned nostrum, that some vile ‘Indian compound’ will be thought to have more virtue than the most accurately proportioned prescription which represents the best that modern science can do in the adaptation of a particular remedy to a particular ailment. That the patent medicine business is a most gigantic fraud and curse will I believe be granted by every scientific man who has made himself acquainted with the subject. Its immense profits are attested by the square miles of advertisements that disgrace the modern newspaper and magazine. Fortunes made from the fortunes spent in such advertising, along with the commissions to the lesser dealers, are drawn from a credulous people who not only receive no value in return, but in most cases doubtless are actually injured as a result.
That no student of biology can be deluded by such preposterous claims as characterize these compounds, in fact by any system of cure not based on sound biological principles, seems only a logical result of his training. I do not recall ever seeing the name of a biologist among the host of those who sing the praises of some of these rotten compounds. Mayors, congressmen, professors, clergymen and other presumably educated parties appear along with the host of those who fill this guilty list, a list that should be branded as a roll of dishonor. I believe that educated men owe some measure of effort toward the abatement of this plague. Naturally the medical profession is thought to be the rightful source for action, but among the uninformed any effort there is attributed to selfish motive. Certainly some measure of reform in this direction would be a service to mankind, and while no sensational crusade may be necessary, each one who knows enough of the laws of life to appreciate the monstrous folly of this business has it in his power to discourage it within the sphere of his individual influence at least. Newspapers are mostly choked off by the immense revenue derived from advertising, in fact I have known some which depended upon this as their main source of support, and have heard the candid statement that they could not have existed without it. All the more honor therefore to the few, and there are a few, which absolutely refuse to allow such advertisements in their columns.
That the modern physician must have a thorough knowledge of biology has become more and more apparent. He has to deal with life, and life thus far at least cannot be rendered into mere mechanical, physical or chemical factors. The activities of the human machine have much that must be studied from the basis of organic nature. If we do not know all the factors or forces of life we do know that there is a complex or combination of forces radically different from any single force of inorganic nature. Chemical affinity, physical attraction and repulsion, mechanical forces may furnish many aids, but the study of life activities must go still further. To do this we must recognize the laws of organic life, the forces of growth and nutrition, of reproduction, of evolution, in fact a host of forces which have no counterpart in the inorganic world.
Modern agriculture and horticulture are so dependent on the principles of biology that to dissociate them does violence to thought. Indeed this relation has existed through all recorded history, but in no period has the utility of biologic laws been so intimately blended with all the processes of cultivation.