1002 



SCIENCE 



[N. S. Vol. XXXIII. No. 861 



except the increased pig-mentation which is 

 very slow to disappear. 



In this reaction we have had simpl.y the 

 familiar picture of sunburn. But the process, 

 in many cases, goes much further, and then 

 there occurs a reaction which is peculiar to 

 X-rays and radium. After the development 

 of an inflamed, reddened area of skin the 

 surface becomes intensely congested, purplish, 

 and then blisters form. At the same time, or 

 before, the hairs loosen and fall out. Next the 

 blisters rupture and leave a surface covered 

 by a necrotic pellicle, like a diphtheria mem- 

 brane. And the reaction may go still further, 

 with the formation of an ulcer whose striking 

 characteristics are its painfulness and its 

 extreme indolence, showing, it may be for 

 months, no tendency to regeneration. The 

 process may stop at any of the stages de- 

 scribed above. If subsidence occurs short of 

 ulceration the skin may again become normal, 

 but after the severe reactions without ulcera- 

 tion, and after ulceration, when healing takes 

 place there may be very distinct permanent 

 changes in the skin. The hairs grow sparsely 

 or not at all ; the pores are very fine or absent, 

 from destruction of the glands of the skin. 

 The skin is thinned, with here and there 

 roughened horny points or patches up to the 

 size of a finger nail, and the surface is red- 

 dened from numerous dilated capillaries which 

 show through the thinned horny epidermis. 



We have here, as a result of these powerful 

 forms of radiant energy, a picture of extreme 

 interest. The condition is in fact an exact, 

 sometimes an exaggerated, picture of the 

 atrophic senile skin, with its dilated blood ves- 

 sels and senile keratoses. As a matter of fact 

 the picture is so nearly that of senile skin that 

 I was able, in the case of X-ray lesions, to 

 predict that cancers of the skin would be 

 found to develop in them because the keratoses 

 of old age are so frequently the starting point 

 of cancers. It would take us too far from our 

 subject to give all of the reasons for the idea, 

 but the identity of chronic radium and X-ray 

 changes in the skin with those of the senile 

 skin, strongly indicate that the senile changes 

 of the skin are in good part the result of the 



less powerful action over a long period of 

 years of sunlight. Another fact, that is be- 

 side our topic, is highly interesting in this 

 connection : Cancers develop in the keratoses 

 of X-ray and radium dermatitis, and in them 

 we have one form of carcinoma which is di- 

 rectly traceable to its exciting cause ; and only 

 by bringing in a deus ex machina in the form 

 of later infection can one avoid the conclusions 

 that at least in these lesions we have cancer 

 which is not of microbic origin. 



When radium is applied to various patho- 

 logical lesions^ in the skin the same phenom- 

 ena occur that are seen in healthy skin, with 

 the addition that under proper precautions 

 selective destructive effects may be produced 

 upon the diseased tissues. Take, for illustra- 

 tion, nodules of tuberculosis or of carcinoma 

 or sarcoma (cancers) in the skin. With 

 proper care in grading the applications a re- 

 action may be produced which will cause these 

 tissues to be entirely destroyed, while this re- 

 action is not siifficient to destroy the normal 

 stroma in which they are situated, or, if it 

 does destroy the normal tissues in the in- 

 volved area, they will regenerate with the 

 formation of healthy scars. It is also found 

 in itching and painful conditions of the skin 

 that the applications have a definite anesthetic 

 effect. 



The microscopic changes in tissues under- 

 going a radium reaction are even more inter- 

 esting than the gross changes. In the early 

 stages of radium irritation sections show evi- 

 dences of proliferation of the tissue elements, 

 such as indicate an over-stimulation of the 

 cells by a peculiar irritant. These changes 

 are most marked in the tissues of the greatest 

 functional activity. At first there are an in- 

 creased production of pigment, and an ex- 

 aggerated proliferation of the germinal and 

 younger (deeper) cells of the epidermis, espe- 

 cially of the cells of the follicles of the epi- 

 dermis; in the corium or body of the skin, 

 there are dilatation of the capillaries, an infil- 

 tration of round cells, and oedema — the 

 changes of inflammation. Later the changes 

 become exaggerated : there is proliferation of 

 the inner layer of the blood vessels (an ob- 



