IT will be remembered that the late King Edward took a keen personal interest in the advancement of cancer research, and that he was also an enthuse-astie supporter of the movement for the establishing of a special radium institute in the metropolis, where the study of the application of radium for the cure of cancer and for other therapeutic uses should be carried on. The realization of this institute became possible through the generosity of Viscount Iveagh and Sir Ernest Cassel, and the official opening of rhe new establishment took place on August 14th. The radium institute is equipped with all the modern appointments required for successfully carryinrs on what promises to be one of the most important branches of medical research. Our illustrations give only a few samples of some of the special apparatus installed. The most important asset of the institute is of course its stock of radium, amounting to 1 gramme and valued at $75,000. Among the special instruments of the institute may be mentioned a very fne-chemical 'balance which weighs to one-thousandth of a milligrane (about one hundred-thousandth of a grain), and a -very remarkable microtome, or microscope-section cutter, which will make no less than 25,000 slices from one inch of material. Its extreme fneness has -been graphically described by saying that it would cut a blood corpuscle into eight pieces. The application of radium for therapeutic purpOS2S is still in its infancy, but some of the results obtainerl are most encouraging, and the present juncture seems a fitting occasion to pass in brief review some of the principal methods employed and effects observed upon the healthy and diseased organism. Radium rays have an unmistakable bactericidal action, both in artificial cultures and within the organism. As may naturally be expected, the effed increases with the amount of radium, and the thr:)8 kinds of rays, the alpha, beta, and gamma rays act in proportion to the extent to which they are absorbed, the highly penetrating gamma rays 'being least effel- tive. A rather peculiar effect has been observed in the case of luminous bacteria, a small mass of radiu;n contained in H luminous bacterial culture appeared surrounded by a small dark area, due presumably to bactericidal action. Immediately surrounding Ithis dark area is a ring of increased brightness. The eause of this stimult£tirg e!eet is' unknown. Accord, ing to some obfl2rvers radium rays diminish the virulence of ralies toxin, but Vanysz found the rays ineffecNve when applied to a fresh preparation of the spinal cord. As regards the medical application of ra8iurii tre"tment, this has hitherto extended princlpally t, skin affections, ulcers, tumors and cancers. In the {reatIlcnt of vascular tumors the radium salt is mixed \ih fine ly powdered barium sulphate; and spread with varnish in a thin layer ou a metal plate. This is COil-veniently mounted upon a handle, an d , then preseris tile appearance shown in our illustration. The treatment, as described by A. C. Jordan in a review in NIU,TC of Prof. Gaucher's book on RadiograplY, consists in the application of this disk to tM diseased portion, the dose being regulated according: to the form and extent of the tumor. AnothE)r- luethodJJs to give smaller doses filtered through s}reens ' l ich absorb the less penetrating rays, longer e x p' s ures bing ill this cas e given. The results obtaln e d are very satisfactory, andon the whole, better than those secured by any other means. In the treatment of scar tissu8 tumors veryfavorable results are obtained both by X-ray and yj radium treatment, ).ut radium is less liable to caUse inflammatory troubles. The activity of radiIlIi is usually expl'essed in terms of that uranium. If the i atter 'be taken as the unit, the activity of pure radium is tWo ,nilliom In mixtures of radium and barium salts, the activity of the mixture is inversely proportional of the quantity of the barium salt present. In the treatment of cancerous tumors, preparations of an activity of 500,000 are used, consisting usually of four to ten milligrammes of powder containing one part of radium salt to three of llarium salt. Cancers suitable for radium treatme!t range from those of small size to those of 20 to :JO square centimeters in area. Deep-seated cancers are subjected to a speeial treatment, the rays being filtered by passing through a ” thickness of lead ranging from one-half to sever,ll millimeters. This permits only the highly penetrating rays to enter the tissues. Long exposures varying from 24 to 120 hours are given. It is found that the high l y penetrating rays produce very little change in the healthy cells, while they have a selective action upon the cancer cells, causing their destruction. The progress of a successful case is described by Mr. .. Jdrdan in the review quoted as follows: "After a short time (three to eight days) the tumor commences to diminish in size. Cicatrisation then begins and is completed in two to four weeks, or longer in obstinate cases. In the case of ulcerating tumors, a certain amount of discharge occurs during all the stages. For large and deeply-extending tumors the method of 'cross, “fre' is usually employed, two or more radium apparatus being applied at different points around the tumor in such a way that the ultr,l-penetrating rays cross in the depths of the tumor. In this way the deeper parts of a growth can be subjected to the influence of the gamma-rays far more effectively than with a single disk of radium." In addition to the method of treatment described .above, various other modes of procedure have also been proposed and practiced with varying degrees of success. Among these, it is interesting to note in particular the therapeutic use of radio-active baths, inasmuch as the supposition naturally suggests itself that som e of the natural waters famous for their health'giving qualities, owe rthese to the presence of radioactive substannes. This subject has been much discussed, and it will suffice to remark here that probably the action in such eas,es takes place by inhalation of the emanation arising from the water.