ably each man has his own purin ratio as each one has his own urea factor; and until we can ascertain this for the individual in health it is a waste of time to argue as to the effect of the increase or decrease of the purins excreted on the general health.” TABLE XI

"Look at Table II. Here in case A we have practically the same ratio of purins to urea at the close as at the beginning

of the treatment, although the treatment immediately improved the general health." The same may be said of another case where the ratio is 1 in 55 before, and 1 in 53 after treatment; and yet my notes say regarding this case at the close of the treatment: 'General condition improved, no rheumatism, no restlessness of legs now.' The rheumatic condition must be more than a mere matter of purins."

"Look again at B and C, table II, and you will find very little change in the purin urea ratio in either, and yet, in the former at least, the condition improved vastly after the electric treatment."

"In case B, one of obesity, the urea and the purins have both increased under the treatment. I have pointed out, however, that this is not an invariable result. Indeed, looking at case A, you will see that where a like benefit had followed, exactly the opposite had occurred.

"I have left myself very little time to speak of the Joulie urinary coefficients. Let me just say that by this is meant the actual amount of phosphates of the urina sanguinis, per litre per cent. specific gravity divided by the total acidity per litre per cent. specific gravity. "The normal figure for the phosphates reckoned as P, O, is 11.17, that of the acidity 4.55; the ratio being thus 2.45."

"From the variation in these figures Joulie draws important conclusions regarding the metabolic processes and the indications for treatment. Whether electric treatment by high frequency currents would modify these figures, I have not yet settled in my own mind, though I have made numerous experiments in this direction.'

Retino-Cerebral Mechanism.-"I have considered the physiological effects of high frequency currents from the points of view of the cardio-vascular, thermo-genetic, gastro-intestinal, and renal systems. Can any of these, or all of them put together, explain the various signs and symptoms we know to expect from this treatment? I am sure they cannot. They give no explanation of certain sensations remarked upon by patients when undergoing auto-condensation treatment. One patient will say that the after-effect is a sense of "comfortable weariness in contrast to fatigue or faintness." Another I have heard remark: "I feel, for an hour or two after, a restful weariness, which is just lovely." One lady, after the vacuum electrode from the high frequency solenoid had been applied to the supra-orbital region for neuralgia, remarked to me the following day: "I don't know what you have done to me or how you have done it, but since yesterday a load has been lifted from my mind and all my cares are gone." For years this lady seemed to have a weight of care on her, and there had, I knew, been much cause for this. Yet at her subsequent visits and till I last saw her she declared that her burden of mental distress

had not returned. Unfortunately this is an exceptional case; but it will serve as an illustration of the point I wish to enforce, viz., that some action on the central nervous system takes place under the therapeutic use of these currents. How is this effect to be seen or measured? We cannot see what is going on in the brain, but we may see and measure what is going on in the retina, which, after all, is a prolongation of the brain. What is called the "after-image" may by the measurements of its duration give us some indication of the condition of the retinocerebral mechanism. Physiologists whose works I had consulted, declared that the duration of this after-image was proportional to the cerebral fatigue present. Haig maintains that the undue prolongation of the positive after-image is due to a state of collemia of the capillaries of the retina, and this condition, according to him, is caused by excessive uric acid. in the blood, which again is a cause of cerebral malnutrition. I tried to measure the duration of the positive after-image on myself, but gave this up, for several reasons. The exposure of the eye to a strong light for several seconds was uncomfortable, if not mischievous, besides, it seemed impossible for me to fix a moment of time in the course of its disappearance as a measure of its duration, and further, it continually eluded me in my endeavor to keep it stationary. I then decided to measure the duration of the negative after-image as an index of the cerebral fatigue. I soon, however, had reason to doubt whether this, the duration, was directly proportional to the cerebral fatigue, and I began to suspect that it was rather inversely proportional to this; since the fresher I was, the longer did the after-image remain. I also noticed that the duration was longer in the morning than at night, and longer with the young and the strong than with myself. On satisfying myself as to these points I consulted various other authorities and discovered that the opinions of physiologists were about equally divided on the subject of the after-image as an indicator of the retino-cerebral condition'; some maintaining that its duration was directly proportional to the fatigue, others that it was inversely so.

His experience has led him to the following conclusions: That the duration of the negative after-image is different in different individuals. That in the same individual it differs according to the state of the health, being longer when the person is well and fresh than when ill and fatigued; according to the time of day; being, at least in my own case, longest just after breakfast, and shortest at bed-time. I could, indeed, tell with a fair amount of certainty how fit or unfit I was going to be during the day by taking my negative after-image in the morning, and I could fairly correctly gauge what it was going to be when I had finished my day's work. When, by reason of temporary good spirits giving me the feeling of being particu

larly fit, I expected to find it high in spite of a specially hard day's work, I discovered that this was not the case; the duration being proportionate to the previous fatigue. I can, with a metronome, beating half seconds, reckon the duration in my own case to a quarter of a second. A considerable amount of experience is necessary, however, to be able to measure with sufficient scientific accuracy the duration of even one's own after-image. Accordingly, I have not been very successful with other people; but I recommend the matter to your consideration as interesting and as of scientific value. The examination must take place as nearly as possible at the same hour, the light must be the same, the distance of the light from the image the same, and the distance of the eye from the object and the image also the same, as well as must the metronome beat exactly at the same rate and for the same number of half seconds, before the eye is turned towards the white paper. The image generally appears at once, but with some people there is a delay of a few half seconds before its appearance. With most the image returns two or three times, but this is not reckoned in the measurement. Unless the eye be kept fixed on one spot the record is spoiled. Accordingly, I have, as you see, fixed a pin in the center of each paper to keep the eye fixed on, since if it wanders from the spot it was originally fixed on the image at once disappears.

PHOTOTHERAPY.

EDITED BY MARGARET A. CLEAVES, M. D.

Action of the Uriol Light on the Skin, and its Therapeutic Use in Dermatology. By Carl Stien and Dr. Hesse, Archives of the Roentgen Ray, August, 1907. From a condensed translation from the Muenchener Mediz. Woch. of February, 1907.

This report of the actions of the Uviol light (modification of the Cooper-Hewitt light) treats of the action of the light upon the normal skin and also as a therapeutic agent. The writer's experiments demonstrate that this light will produce a slight erythema with an irradiation of fifteen minutes, at a distance of five centimeters, and after a lapse of five hours, a patch of redness appeared over the area of irradiation. This increased during the next few hours to a uniform redness, which disappeared on pressure. The redness would increase for two days, remaining one day at its height, dying down on the fourth day to a brownish discoloration, which did not disappear upon pressure. This was succeeded in from four to six days by a lamelliform desquamation, followed by slight discoloration, which after some time disappeared. The action of the light was shown to be more intense with blondes, and

far less marked than it is with dark complexions. Ten minutes may suffice to raise a blister upon the light skin, while fortyfive minutes would barely cause a redness upon the shaven scalp of a dark-complexioned boy. In a case of indurated

eczema there was no apparent result from prolonged irradiations of half an hour to an hour, repeated every day for a week. Observation shows that Uviol light produces only a condition of hyperemia without any histological change, the appearance being that of a severe solar hyperemia, without deepseated effects as occurs after exposure to the Finsen light.