The Spectator., 1914-12-08
Copyright. 1914. by A. s. Gray) SUNLIGHT AND INFECTIONS.

The daily newspapers recently pub lished the following paragraph: "At conference of the Association for the Prevention of Consumption at Leeds, England, Sir William Osler of Oxford. formerly of Johns Hopkins university. startled the audience by the announce ment that 90 per cent of all people probably have a small focus or area of tuberculosis
 The audience was "startled" by the assertion only because we habitually give very little heed to any matter that does not immediately concern us indi- vidually, or that is not forced upon us by circumstances that compel our con centrated attention. The statement has been made by Osler and by many other authorities in substantially the same words again and again in the past, but 1t did not stick" at the time solely for the reason that few happened to be in a receptive mood. It is an undeniable fact that unless one is in a receptive mood the most obvious and sublime truth falls on unheeding ears, and in this fact we have a most instructive illustration of the beginning of tuber- cular disease in our bodies, the prin- ciple involved being identical in either case. For just as the mind must be re- captive to be able to receive, to hold and to develop a truth, so must our bodies be receptive in order to receive, hold and develop tubercle bacteria, or any other bacteria. No life can pos sibly develop in an unfavorable en- vironment.
 It is perfectly we'll known among the medical profession that whatever may have been the cause of death. postmortem examinations usually show a small area where tuberculosis has existed, but that has been cured" by natures method of fencing about and imprisoning any invading matter she is strong enough to overwhelm. Any invading bacteria are either devoured by the white corpuscles or are fenced about and "encysted" if the organism has sufficient vitality to fight; but 1T there Is not sufficient vitality then the individual becomes one of the 150.0OO that die annually in this country from some form of tuberculosis.
 We have noted that white sunlight not only develops plant life, but that 1t also exerts an inhibitory or restrain ing effect as we'll This Is clearly proved by the fact that certain plants are found to grow faster and taller under red and blue light than they do under white light, and that they are stunted or even killed under green or violet light.
 We do not know why plants react in this way, but we have positive proof that they do. And it is equally certain that bacteria generally are either quickly killed or profoundly modified by the rays at the violet end Of the spectrum. It should require no great strength of the imagination. then, to understand why we have epidemic out breaks of pinkeye, influenza, diph- theria, sore throat. measles. scarlet fever "colds" and the like following any profound disturbance in meteoro- logical conditions that tend to inter- fere with the normal amount of pure sunlight reaching us. Because 1t mat ters not what 1t may be. whether 1t is smoke, dust from volcanoes, excess moisture condensing into clouds, col ored glass, or brick walls and tin roofs, anything standing between any living thing and the sun must mate rially modify that life. It's vitality Is fin direct ratio to the amount of energy received through its normal line of connection with the sun.
 We prove this with plants by grow ing them in dark rooms. or under col ored glass, which Is only simple means for shutting out such parts of the spectrum as we desire. and also it is proved by the extent to which large areas of growing crops are tn- fested with disease during long con- tinued cloudy weather.
 It has been conclusively proved that the sum of the work executed by the animal. and of the heat which 1t gives out, is exactly equivalent to the chem ical potential energy taken in with its food, and this we know can be equal only to the kinetic energy of the sun light stored up during the production of the plant All the potential energy of vegetable matter Is converted sun light.
 And today our individual energy is derived quite directly from that same source. Four factors are necessary to produce any plant crop-eeed. soil. moisture and direct sunlight: and the absence of any one of the last three factors will inevitably result either in . total failure of the seed to germinate or in some abnormal development. Seed and favorable environment re- suit in a plant growth; and germ. which is only very small plant, fin an o,tcv-nur hodies for tn2tanca--