FOOTNOTES:
[2] When ultra-violet light is allowed to fall upon a metal it causes the metal to emit electrons and thus to acquire a positive charge, the velocity of the emitted electrons being exactly proportional to the frequency of the incident light. Or when light of X-ray type falls upon the surface of almost any substance, it takes hold of an electron in the atoms of that surface and hurls it out into space with a speed exactly proportional to the wave length of the light. This phenomenon is known as the photoelectric effect.
CHAPTER V
ULTRA-VIOLET LIGHT IN HEALTH AND DISEASE
That both the compound rays of ordinary sunlight and ultra-violet rays (“artificial sunlight”) are highly effective in the treatment of a number of complaints is now well known. They are both in general use for the external treatment of rickets, tuberculosis, and a number of other diseases. Light-rays are also applied to hasten the healing of wounds.
The use of the sun as a healing agent seems first to have been developed in a scientific way by Dr. Neils R. Finsen, a young Danish physician who was later awarded the Nobel Prize in Medicine. His original researches were undertaken toward the end of the 19th century. Then Dr. Rollier opened the first sunlight clinic in 1903, and in 1910 established his school at Leysin, in the Alps. Dr. Rollier is now treating about 1,000 patients, mostly afflicted with various forms of tuberculosis of the bone. The sun cure is also used to some extent for pulmonary tuberculosis, and with considerable success. (See my Man’s Debt to the Sun, Little Blue Book No. 808, Chapter IV.)
According to Dr. Rollier, exposure of the diseased to the sun’s rays is efficacious in the treatment of anemia, malnutrition, bone and gland infections and various types of tuberculosis, and is a body builder for convalescents. On the outskirts of San Rafael, California, is a novel sun sanitarium, Helios Sanitarium, modeled after the Alpine sanitaria of Dr. Rollier.
Two investigators have recently studied the comparative germ-destroying power of the blood in healthy and ill persons, before and after exposure to sunlight. It was found that the germ-killing power of the blood was increased when the sun bath lasted for a certain length of time. It was shown that too long or too short an exposure decreased the blood’s power. It was decreased also in patients who had fever. Several other conditions were found to influence the results. Physicians believe that several points of practical value may emerge from these experiments. One important and useful result is that they offer a new method to guide and gauge the effects of treatment in tuberculosis and other diseases.
The practice of X-ray treatment (since 1910 included under the more general term radiotherapy) includes treatment not only by X-rays, but also by all kinds of rays—treatment by heat, by the sun’s rays, by ultra-violet rays, and even by violet rays. The rays of radioactive substances used in medicine come under the etymological term of radiotherapy. But in general practice, amongst radiologists, the term is applied to treatment by X-rays alone. Nevertheless, it is now well established that the ultra-violet rays are not only bactericidal, but that they also play an important role in the treatment of certain diseases, and in the maintenance of good health. On the other hand, these rays produce a certain irritability among persons of the white race in the tropics, which cannot be regarded as healthful in their general effects.
Since the amount of ultra-violet light coming from the sun has been shown by Abbott to be variable, it may be that some of the irritability which seems to be general among the inmates of our public institutions on certain days is due to this change in the sun’s outpour of ultra-violet radiation. As Dr. E. E. Free remarked not long ago:
“Put these facts together. Ultra-violet rays affect life. The amount of ultra-violet coming from the sun is variable. Does this mean that some of the obscure, day by day variations of health can be due to this? Some days everybody seems happy and cheerful. Other days everybody is depressed. Still other days are breeders of ‘nerves.’ Maybe the ultra-violet does it. Maybe not. Doubtless the investigators will find out presently.”
Recent experiments at the Maine Agricultural Experiment Station, conducted under the direction of Dr. John W. Gowen, have led to the important discovery that milk from cows that have been treated with ultra-violet light, from mercury-vapor quartz lamps, contains a much larger amount of the substance—presumably a vitamine, or vitamines—that prevents rickets in children and young animals. At any rate, it was found that the milk from cows deprived of sunlight and ultra-violet light was quite deficient in the anti-rachitic factor. Animals and birds fed on the sunless milk uniformly developed rickets.
The Holstein-Friesian cows used in the experiments were of nearly the same age and calving date and all received like treatment as to feed, temperature, etc., and stood side by side in the same barn. “Throughout the treatment,” says Dr. Gowen, “these cows did not leave the barn. For one month none of the cows received ultra-violet light. For the second month two cows received ultra-violet light 15 minutes a day, generated from a Cooper-Hewitt alternating current light at three feet above their backs. For the third month these cows received ultra-violet light for 30 minutes a day under the same conditions. In the meantime Rhode Island Red chickens were allowed to develop rickets, shown both clinically and by X-ray photographs. They were divided into two lots, one lot of these chickens receiving milk from the ultra-violet cows, the other of two lots of chickens, milk from the control cows. Both lots received all the milk they wished.
The chickens have now been under treatment 50 days. The lot receiving milk from cows exposed to ultra-violet light are in good condition with no appearance of rickets in X-ray plates. The lot receiving normal milk has moved progressively toward more extreme clinical and X-ray rickets. The experiment was repeated, using the milk from these same cows on White Leghorn chickens showing clinical and X-ray rickets. Five chickens were in each lot. After 38 days’ treatment four of the lot receiving milk from the ultra-violet cows are almost cured of rickets, showing only a very slight stiffness. The fifth chicken shows some stiffness. Four of the lot receiving the normal milk show constantly increasing symptoms of the more advanced stages of clinical rickets.
These results point to the conclusion that more of the substance necessary to cure rickets is absorbed by the cow exposed to ultra-violet light and secreted by her in her milk. The cows prevented from receiving ultra-violet light are not able to secrete this anti-rachitic substance in sufficient quantities to cure or allay the process of clinical rickets. The results thus point to an environmental factor transmitted by the cow to her offspring through the medium of her milk. They further suggest that the high incidence of rickets in children during the late winter months is due to their mothers not receiving ultra-violet light either during pregnancy or while in lactation. Furthermore, it would appear that cows’ milk produced especially for baby-feeding should be from cows which have access to ultra-violet light either from the sun or from some other source.
Dr. C. C. Little of the University of Maine, and his associates, fully demonstrated the value of sunlight to animal life through experiments on a flock of 233 chicks. The chicks were divided into three groups and all were given the same diet. One group was kept in natural sunlight, the second was kept in sunlight that went through window glass, and the third was given both natural sunlight and extra ultra-violet rays produced artificially. The last class grew the best. The class that got only natural sunlight grew normally. The class kept behind window glass all developed bone disease. The glass of the greenhouse allowed the light of the sun and the heat of infra-red rays to get through. But it screened out the ultra-violet waves.
The beneficent effects of invisible ultra-violet rays are seen in both the organism exposed to them and the food consumed. This is true whether the rays come direct from the sun or by means of a quartz lamp. Ordinary glass lamps prevent the ultra-violet rays from passing out. But not all kinds of foodstuffs by any means are favorably affected by the rays. Only those foods which contain fat seem to be materially improved. The value of milk and of cod liver oil is greatly enhanced by exposure to the rays. Dr. Benjamin Kramer has been highly successful in treating babies affected with rickets by subjecting milk itself to the action of ultra-violet light.[3]
As early as 1923, it had been shown by feeding experiments with various types of animals at the University of Wisconsin that sunlight was acting either directly upon the animal or upon its food. The same dietary was found to produce contradictory results. It was established—especially by H. Steenbock and E. B. Hart—that sunlight is indispensable to man and beast, in that it is the determinant of the efficiency with which calcium can be assimilated and retained. (See their report, Journal of Biological Chemistry, Vol. 62, page 577, 1925.) Calcium, it is pointed out, needs to be conserved because in proportion to the body needs it is not found abundantly in foods and feeds. Steenbock and Hart tell us that sunlight plays the particular rôle of conservator “by virtue of its content of ultra-violet radiations of approximately 250 to 302 millimicrons in wave-length, but unfortunately these are not present in sufficient degree to provide a wide margin of safety for the animal. As a result we have rickets in the young and poor dentition, restricted lactation, abortion and impoverishment of the skeleton in lime to a dangerous extent in the adult.... The ultra-violet rays bring their effect through the medium of certain compounds widely distributed in plant and animal tissue, so that practically any foodstuff can be ‘anti-rachitically’ activated. ‘Make hay while the sun shines’ is more than a mere poetic slogan, for hay made in the dark is devoid of rickets-preventing properties” (Science, December 4, 1925).
The careful experiments of J. S. Hughes showed that chickens receiving a standard scratch feed and mash, supplemented with sprouted oats and buttermilk, developed rickets (weak legs) when deprived of direct sunlight. Chicks receiving the same feed but given sun baths developed normally, although they were confined in a very small pen, with little opportunity to exercise. Light from ordinary electric bulbs had very little, if any, beneficial action. Light from the Hereus mercury arc lamp was very beneficial. Cod liver oil also proved to be effective in preventing rickets in chickens as in mammals.[4]
That such fats as olive oil and lard may be activated by exposure to ultra-violet rays and used as a substitute for cod liver oil in the treatment of rickets is evidenced by experiments reported by the Department of Agricultural Chemistry of the University of Wisconsin. In the series of experiments now published, olive oil and lard were exposed to the action of the ultra-violet rays from a powerful mercury-vapor quartz lamp, for periods of time ranging from half an hour to 17 hours.
After exposure to the rays these fats were fed to a group of experimental rats in which rickets had been produced, and the activated olive oil and lard were found to have the same beneficial results that follow the administration of cod liver oil. The weight of the rats increased and an analysis of the bones showed an increase in the calcium content.
Some of the activated olive oil, which had been stored in a stoppered bottle, showed no change in potency ten months later. It was found also that the fats might be activated by the rays from the open carbon arc, the iron arc, and sunlight; but that exposure for such prolonged periods as 17 hours destroyed their potency. This destruction took place even on cod liver oil.[5]
It has long been known that human tissue is more actively changed by light when it has been “sensitized.” Quinine, esculin, fluoresceine, etc., are examples of tissue sensitizers, in addition to their other effects. The most powerful of all known sensitizers is haemato-porphyrin—or simply “porphyrin.” This sensitizer is a purple substance closely allied to the haemoglobin that gives blood its red color. Subtracting its iron and albumin from haemoglobin by appropriate chemical processes leaves porphyrin. This substance reacts strongly to the ultra-violet rays, in rare cases causing a disease which turns the teeth to a deep purple hue. Victims of this uncommon ailment have to wear gloves constantly, and when going out of doors during the day time must put on heavy veils.[6] Porphyrin is capable of dissolving the red corpuscles of the most dissimilar animals in the presence of sunlight. But neither the haemato-porphyrin nor the light alone is capable of injuring the animals. Only the combined effect of the two can harm them. A physician experimentally injected an exceedingly minute quantity into himself and then exposed himself to a moderate light, and became very ill.
Hausmann found that even the diffused sunlight of an early spring day in Vienna was sufficient to cause the death of white mice which had been subjected to small quantities of this strange substance. Dr. E. C. Van Leersum, of Holland, proved by experiments with rats that the utilization of lime by our bodies can be controlled almost at will by this “sensitization” process. Rickets, or a condition indistinguishable from rickets, can be produced or cured by proper control of the sensitization.