1904.] On the Action of Radium on Micro-organisms. 375 



toxines of the affection from which the organism is suffering. In 

 other words, normal temperature is preserved by a mutual see-saw 

 action of these centres — the thermogenetic and the thermolytic. 



We recognise fully that, for a more perfect understanding of death 

 temperatures, it is necessary for the observers to examine the patients 

 for themselves, and not to trust to records, however many or accurate 

 they may be, so that they can note in each case the changes in the 

 skin, the circulation, the respirations, etc., concurring with the varia- 

 tions of the bodily temperature. Nevertheless, we venture to put 

 forward our investigation and views, not as physiologists, but as 

 clinical observers, with the hope of pointing out new lines of research, 

 by which may be increased the knowledge of the regulation of animal 

 heat. 



" A Note on the Action of Badium on Micro-organisms." By 

 Alan B. Green, M.A., M.D. (Cantab.). Communicated by 

 Sir Michael Foster, K.C.B., F.R.S. Received April 11, — 

 Bead May 5, 1904. 



[Plate 11.] 



The radium salt used in these experiments was 1 centigramme of 

 radium bromide, bought of Messrs. Buchler and Co., of Brunswick, 

 in June, 1903. It was contained in a vulcanite and brass capsule, 

 fronted with thin talc. The radium was enclosed immediately behind 

 the talc, and the circular area over which it was spread was about 

 3 mm. in diameter. The radium emanations which were applied to 

 micro-organisms were such as passed through the talc, i.e., the f3 and 

 y rays. 



Dr. E. F. Bashford, to whose kindness I am greatly indebted for 

 the use of the radium, has informed me that Sir William Ramsay 

 tested the preparation for the intensity of its combined ft and y rays, 

 the latter being a practically negligible quantity. The results showed 

 that, on comparison with samples of radium bromide giving a 

 virtually pure spectrum of radium, these rays were practically 100 per 

 cent. This radium salt was, in fact, a pure preparation of radium 

 bromide. 



Dr. Bashford also informs me that this radium bromide caused pig- 

 ment to disappear after 18 days from a mole with 15 minutes' exposure, 

 the talc being in contact with the surface of the mole. Five minutes 

 such exposure produced a marked skin reaction, while 20 minutes' 

 exposure caused a reaction proceeding almost to ulceration. 



I found that the radium was itself luminous, and that it could 



2 D 2 



