From the study of rays of measurable wave-lengths we have lately sailed under the guidance of M. Henri Becquerel into another region where it is doubtful whether all the rays conform to the undulatory theory. In fact some of the rays are believed to be charged particles of matter, charged, that is to say, with electricity. Beyond doubt they are possessed of very extraordinary properties, inasmuch as they are able to penetrate the clothing, celluloid, gutta percha, glass, and various metals. They are, moreover, endowed with a no less remarkable physiological action, producing blisters and ulcerations in the flesh which are difficult to heal... From this we can quite understand that there is no exaggeration in the statement attributed to the discoverer, Prof. Curie,... that he would not care to trust himself in a room with a kilogram of pure radium, because it would doubtless destroy his eyesight, burn all the skin off his body, and probably kill him.

From Nature 17 September 1903.


In the course of developing equipment for other problems, we have made some measurements of the total radioactivity content of several humans and a dog, using a technique which may have other applications in biophysics... (See Fig. 1). A dog of approximately 35 lb. weight was anaesthetized and counted in the small insert. A solution containing 0.1 µC. radium in equilibrium with its decay products was injected into the femoral vein, and (five min. after injection) the dog was again 'counted'... The large insert was used for the measurements on humans, who were able by doubling up to be entirely within the insert... In the absence of the radium group, the potassium content of the body can be measured with good accuracy, and it is quite conceivable that application of these techniques could yield important results in the study of the role of potassium in the metabolic process.

figure 1

Figure 1

F. Reines, C. L. Cowan et al.

From Nature 19 September 1953.