cury arc is beginning to find its way into these institutions. In the child welfare centres, on the other hand, the mercury arc is the lamp that is most frequently used, and it has been found quite satisfactory.

10. Solar Radiation.-There is general agreement among tuberculosis experts that better results can be obtained by heliotherapy than by artificial irradiation, and that when the natural sunshine is available it should be made use of as far as possible. Heliotherapy is practised to a considerable extent at the Scottish sanatoria during the summer, but it is difficult to give regular doses owing to the great variations in the amount of sunshine available. Very little ultra-violet radiation is available in the midlands of Scotland during the winter months, and presumably the same is true of places further north, Mr. Fyfe, Sanitary Inspector, Stirling, began in October 1925 to record solar ultraviolet radiation, using Professor Hill's acetone-methylene-blue gauge. In November of the same year Dr. Watt, one of the medical officers of the Department, began making observations by exposing the gauge at his house on the outskirts of the south side of Edinburgh, and was unable to record any ultra-violet between November 1925 and March 1926. During this same period Mr. Fyfe recorded average daily readings for each month as follows:-October 1.8, November 0-82, December 04, January 0-1, February 03, and March 0-95 degrees. The degree is an arbitrary figure based on the amount of bleaching of the methylene blue when compared with a series of bacteriologically standardised tubes. The highest single reading recorded by either of these observers during summer was 10 degrees. It is clear that, during the months of November to February, the amount of solar ultra-violet radiation is inappreciable in the suburbs of Edinburgh and is very small in the country. In contrast readings for certain English stations published in The Times shew much higher averages. Thus for November and December 1926 the average daily readings at Ventnor were 2-4 and 2-3 respectively.

With the arrival of March the sun at Edinburgh gave an average daily reading of 1.0, and from April to August the average daily readings at Edinburgh and Stirling respectively were :— April (Edinburgh) 1-2, (Stirling) 24; May (Edinburgh) 2.9, (Stirling) 24; June (Edinburgh) 4.1, (Stirling) 4.2; July (Edinburgh) 5.9, (Stirling) 3.8; August (Edinburgh) 5·3, (Stirling) 2.9. The average for Stirling in September was 4.1. From October onwards the readings went down rapidly, reaching 0-2 in December at Stirling and 0-0 at Edinburgh.

One degree on the scale is equivalent to two to four times the ultra-violet radiation necessary to produce erythema of white skin. On an average April day one might therefore require to expose the white skin of the arm to the rays of the sun from sunrise till midday to produce perceptible reddening of the skin. It is obvious from these observations that, for persons who require treatment by ultra-violet rays, artificial sources of

radiation are a necessity in winter and frequently also during the summer.

11. Non-pulmonary Tuberculosis.-Where treatment by ultraviolet radiation is combined with other recognised methods of treatment it is not always easy to determine precisely the actual value to be attached to irradiation. Even after years of experience there is very considerable divergence of opinion on this question among tuberculosis experts. Where the standard of treatment in institutions is maintained at a high level, including an open-air life, it is claimed by some that equally good results have been obtained without the use of artificial light. Yet, even in cases where the principal factor in treatment was ultra-violet radiation, results have varied, and opinions have differed accordingly. It has already been noted that the factors involved in irradiation are complex, and in the absence of reliable standards of irradiation and of precise knowledge of clinical conditions, comparisons are apt to be misleading. In Scotland as a whole opinion is clearly in favour of irradiation. In a large number of cases there is no doubt in the minds of the clinicians that ultraviolet irradiation has been the main factor in hastening recovery; cases that have dragged on for months or years without making progress have responded rapidly to treatment by irradiation. The results have, by some, been attributed in part to suggestion; this may be a factor, but it can hardly be the most important one. The specific effects of irradiation on such things as the mineral content of the blood and the bactericidal power of the blood, to mention only two conditions, are enough to shew that it has a directly biological action. Moreover the universal testimony of light clinicians is that practically every patient irradiated experiences an improvement in his general condition, feels better, eats better, sleeps better, &c. Suggestion is seldom so universally successful.

Dr. Smith, Robroyston, commenting on this general improvement, writes :

"One of the most striking features of the treatment is the rapid improvement in general health experienced by the patients. For the first two or three months there is in the majority of cases a steady gain in weight, but this is not always maintained till the healthy normal is reached, and the putting-on of flesh is sometimes not accompanied by improvement in the lesion. Lassitude and low spirits usually give place to a feeling of well-being and exhilaration, except in cases where an overdose depresses instead of stimulates."

Dr. Taylor, Aberdeen, commenting on the same subject, writes:

"It is necessary to stress the remarkable general response of practically all tuberculous patients, both pulmonary and extra-pulmonary, to ultra-violet treatment. The necessity of counteracting the tendency of such patients

to become morbid and dispirited was one of the most difficult problems of institutional treatment in former days, but with the advent of heliotherapy, reinforced by artificial light therapy, the tendency to introspection and pessimism has been replaced by an optimism of the best description. The patients almost invariably, and at all stages of the disease, become bright and cheerful."

12. Tuberculous Glands.-Irradiation by ultra-violet rays has been particularly successful in the treatment of lymphatic glands, especially those that are superficially situated. Where the glands have broken down and discharged, leaving a sinus, irradiation seldom fails to give good results. The sinus heals, and the scar left is usually a supple one blending well with the surrounding skin. Many of these cases shew very rapid improvement under the effects of the rays, but ultimate cure may nevertheless take many months. Where the glands are enlarged but have not. broken down, the results are more variable. In some cases they gradually subside and disappear; in others they shrivel up into hard shotty masses which do not improve further under irradiation and have to be removed surgically. Glands, sometimes break down during the course of irradiation, and if the abscess be aspirated or a small incision be made to evacuate the pus, the case usually does very well under light, Occasionally a large gland mass is extruded from the sinus.

These facts are generally true of all the principal centres in Scotland. There were variations in results just as there were variations in the methods of treatment, but the evidence in favour of irradiation for tuberculous glands is very convincing. Dr. Cameron, East Fortune, writes: When one has seen the labours and uncertainty of other methods of treatment, one marvels all the more at the results of this." At Robroyston, and at the City Hospital, Aberdeen, many cases are treated at high power (75 ampère) lamps, and at Bridge of Weir Sanatorium, Dr. Crocket combines the general light bath at the mercury vapour lamp with local treatment by the tungsten arc. Occasionally also he gives a dose of X-rays equivalent to one-half of a Saborand pastille dose locally. In most of the other centres, 25 ampère carbon arcs are used and the exposures vary from one to 21 hours. Dr. Brodie, Wishaw, has been particularly successful in the treatment of gland cases. It has been his experience that no matter whether the case came to him with a discharging sinus, with the glands softening or in hard masses, they invariably did well under irradiation. The success that has attended his treatment of gland cases has been such that he now seldom has gland cases in hospital, as they can all be successfully treated as out-door patients. Where softening occurs, he does not hurry over the evacuation of the pus, but waits until softening is complete. A very small incision is all that is required to empty the abscess, after which healing rapidly takes place.

13. Lupus.-Variable results have been got by different

clinicians. Generally it may be said that the catarrhal type of lupus is much more amenable to irradiation than the fibroid type. Some centres shew a high percentage of cures of the catarrhal form; others have been less successful. Most cases improve under light, but some only do so up to a point, after which all benefit appears to cease. The cases that are obstinate are those in which resistant nodules occur, and these are common in the fibroid type. The condition is materially helped by intensive local treatment with the mercury vapour arc, the exposure being sufficient to cause severe local reaction. The results obtained by Sir Norman Walker are striking, but in several centres in Scotland equally striking cures have been obtained by the general light bath alone. Dr. Smith, Robroyston, says: "The response of the catarrhal type is often dramatic. At East Fortune, Dr. Cameron states: "We have had several very wonderful results which could only be attributed to the effects of light applied as a general light bath. It has been stated that the light bath alone will not completely cure lupus. It is not my experience, brief though it is."

,,

The

All cases of fibroid lupus are not equally resistant. At Hairmyres, for example, Dr. Johnston reported cures in fibroid cases with the general light bath, after treatment extending over three and a half months, seven months and eight months. benefits of irradiation as a means of treating lupus have undoubtedly been very great, and no one appears to appreciate this more than the patients, who seem to be willing to continue. treatment for long periods in the hope of ridding themselves of a loathsome affection.

14. Bones and Joints.-Modern methods of conservative treatment of tuberculous disease of bones and joints have given such excellent results that it is not so easy to point to irradiation as an important factor in the amelioration of these conditions. The first essential in all these cases is fixation and rest, and in the case of hip joint disease and spinal disease, unless the light can be taken to the patient, it is often difficult or impossible to take the patient to the light.

Even under the best conditions, prolonged rest in fixation is necessary, and the effects of irradiation in helping towards a cure are not always open to direct proof. There are cases where its influence appears to be negligible, yet there are others in which there can be no doubt of its value. The response appears to depend to some extent upon the blood supply to the affected part. Lesions in sites where the blood supply is good respond better than lesions where the blood supply is poor. Disease of small bones, e.g. the fingers, and metacarpals, and of joints such as the wrist, elbow, ankle and knee, benefit more than deep-seated lesions in the hip joint and in the spine. Yet there are records of good results in both hip and spinal cases. But there are few centres in Scotland where hip and spine cases have been freely treated by irradiation owing to the difficulty of bringing them to the treatment room. For example, at Robroyston, where there

áre large numbers of these cases, very few of them get light treatment. With regard to bone and joint cases generally, Dr. Smith, Robroyston, writes: "I have had experience of the treatment by light of more than fifty cases of bone and joint tuberculosis, two-thirds of them complicated by abscess and sinus formation. Excellent results have been obtained with the smaller joints, elbow, wrist, ankle and knee. Not only have chronic sinuses healed up firmly, but in many there has been complete restoration of mobility and function in the joint. X-ray plates have demonstrated in some of these cases practically entire reorganisation of articular surfaces and parts of bone, even when originally there was extensive destruction. In the healing bone the atrophy disappears, the bony outlines are sharply demarcated, and coarse trabeculæ appear. Eventually it is almost impossible to detect any abnormality in the radiogram. I am of opinion that in almost all cases of tuberculosis of joints the hope of return of function is greatly increased by ultra-violet irradiation. It must be emphasised, however, that fixation apparatus cannot be dispensed with, and patience is essential."

Dr. Crocket, Bridge of Weir, writes: "The value of ultraviolet ray treatment in bone and joint tuberculosis is so thoroughly established that little need be said for or against it. Dr. Rollier's statement that surgical tuberculosis can be cured by heliotherapy in all its forms, in every stage and at all ages, is not an exaggeration. At the Hospital of the Orphan Homes of Scotland we had a number of boys and girls with surgical tuberculosis, many of whom had badly discharging sinuses. We were afflicted with several successive seasons of atrocious weather when sun treatment could not be persisted with. The condition of these cases was stationary, and a quartz mercury vapour lamp was installed. The effects were immediately noted. Ninety per cent. of the cases shewed improvement. When sinuses were present, increase of the discharge was noted at the commencement. This decreased as time went on. It is good practice to cover up those sinuses to prevent the local action of light until the case is well under way. The closure of a sinus is not the main thing, but it is important to have the closure taking place from below. One aims usually at a funnel-shaped sinus rather than a narrow-necked one. The use of a tent often produces this. Cupping also frequently helps to keep the sinus open, and to remove any pus present."

Advanced cases with active disease and temperature are not suitable for irradiation. Open lesions appear to derive speedier benefit than closed ones. Dr. Cameron, East Fortune, states: "The degree of healing and restoration of function that one sees in many cases of open lesions in joints is very wonderful. The child with multiple lesions of bones and joints proceeds to results which a few years ago were undreamt-of."

Similar encouraging results are recorded at other centres. At Aberdeen City Hospital thirty cases were treated, and eighteen of them did well. Of the remainder, eight were from