874 THOMAS ORDWAY AND ARTHUR KNUDSON 



Distribution and Elimination. Radioactive substances differ from 

 the x-rays from the fact that in solution in the form of a salt, or as active 

 deposit of radium emanation, or the emanation itself in solution, thej 

 may be ingested or injected into the animal body. The emanation, th( 

 radioactive gas evolved from a solution of radium, may also be taker 

 into the body by inhalation. A method of condensing the emanation anc 

 the deposition of the active deposit upon sodium chlorid which may be 

 dissolved in water to make an isotonic solution has been described bj 

 Duane. 



Berg and Welker found that after subcutaneous injections the radium 

 (bromid) like barium and calcium is eliminated chiefly by the intestinal 

 tract. Meyer after intravenous injection of solutions of radium bromide 

 showed the presence of radium in the liver, lungs, and kidneys. The 

 ultimate fate was not materially different if the radium was injected in any 

 other manner, that is, subcutaneously or intraperitoneally or if a solu- 

 tion were taken by mouth. 



Salant and Meyer conclude that the elimination of radium is chiefly 

 by way of the liver, kidneys, and the small intestine and to a less extent 

 through the large intestine in some herbivora. Brill and Zehner found 

 that radium chlorid injected into dogs and rabbits was eliminated almost 

 exclusively by the feces and there was very little in the urine. Bagg(a) 

 found that following the injections of active deposit from radium emana- 

 tion there is diffusion of radioactive substance throughout the animal 

 body, resulting in pathological changes in various organs, notably the 

 liver, lungs, kidneys, adrenals, spleen, bone marrow, brain and vascular 

 system. 



Effect on Tissues. It is well known that radiations of Roentgen rays 

 and radioactive substances affect different tissues to a varying degree 

 and that the lymphatic tissue, spleen, lymph glands, bone marrow and 

 sex glands are particularly susceptible (Heinecke and Warthin). Hauscht- 

 nig in describing the technique for radium treatment shows that the mucosa 

 of the intestines and bladder is sensitive to one erythema dose while 

 the muscles of the cervix uteri are resistant to forty, those of the corpus 

 uteri to thirty, and the vaginal mucosa to five or six erythema doses. The 

 dose which destroys carcinoma cells is practically the same as the erythema 

 dose of the skin. Nervous tissues are very resistant to radiations. 



Nakahara, and Nakahara and Murphy believe that by a carefully 

 measured dose of x-rays (Coolidge tube, spark gap % inch, milliamperage 

 25, distance 8 inches, time 10 minutes) within four days there is an ab- 

 normally large number of mitotic figures found in the lymphoid tissue 

 of the spleen and lymph glands. They believe that this indicates accelera- 

 tion of the proliferative activity of this tissue by exposure to x-rays of 

 low voltage. The great variation in the activity of lymphoid tissue nat- 

 urally at different ages and also when due to Intel-current infections and 



