[1] Then recently established by the Royal Dublin Society.

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tubes, containing, perhaps, up to 200 millicuries, or even more, per tube.  Now these very heavily charged tubes give a radiation so intense at points close to the tube, due to the greater density of the rays near the tube, and, also, to the action of the softer and more easily absorbable rays, that it has been found necessary to stop these softer rays—­both the y and ss—­by wrapping lead or platinum round the tube.  In this lead or platinum some thirty per cent. or more of the rays is absorbed and, of course, wasted.  But in the absence of the screen there is extensive necrosis of the tissues near the tubes.

If, however, in place of one or two such tubes we use ten or twenty, each containing one-tenth or one-twentieth of the dose, we can avail ourselves of the softer rays around each tube with benefit.  Thus a wasteful loss is avoided.  Moreover a more uniform “illumination” of the tissues results, just as we can illuminate a hall more uniformly by the use of many lesser centres of light than by the use of one intense centre of radiation.  Also we get what is called “cross-radiation,"which is found to be beneficial.  The surgeon knows far better what he is doing by this method.  Thus it may be arranged for the effects to go on with approximate uniformity throughout the tumour instead of varying rapidly around a central point or—­and this may be very important—­ the effects may be readily concentrated locally.

Finally, not the least of the benefit arises in the easy technique of this new method.  The quantities of

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emanation employed can fit in the finest capillary glass tubing and the hairlike tubes can in turn be placed in fine exploring needles.  There is comparatively little inconvenience to the patient in inserting these needles, and there is the most perfect control of the dosage in the number and strength of these tubes and the duration of exposure.[1]

The first Radium Institute in Ireland has already done good work for the relief of human suffering.  It will have, I hope, a great future before it, for I venture, with diffidence, to hold the opinion, that with increased study the applications and claims of radioactive treatment will increase.

[1] For particulars of the new technique and of some of the work already accomplished, see papers, by Dr. Walter C. Stevenson, British Medical Journal, July 4th, 1914, and March 20th, 1915.

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SKATING [1]

IT is now many years ago since, as a student, I was present at a college lecture delivered by a certain learned professor on the subject of friction.  At this lecture a discussion arose out of a question addressed to our teacher:  “How is it we can skate on ice and on no other substance?”

The answer came back without hesitation:  “Because the ice is so smooth.”

It was at once objected:  “But you can skate on ice which is not smooth.”