22 THE ROYAL SOCIETY OF CANADA 



The Standard Solutions were as follows : — 



I. 100 c.c. of a solution of radium barium bromide in 50% 

 hydrochloric acid, certified to contain 12-2 X 10"^^ gms. radium 

 per c.c, obtained from the United States Bureau of Standards. 



II. 100 c.c. of an acid radium solution containing 1 -5 X 10"^ 

 gms. radium, kindly presented by Professor Boltwood of Yale. 



Weaker solutions of various strengths were made up from these 

 by taking aliquot parts of them and diluting with freshly distilled 

 water and hydrochloric acid distilled from C. P. hydrochloric acid 

 and sodium chloride. These solutions were placed in 250 c.c. 

 conical flasks, permanently connected up with condensers and were 

 boiled out at intervals during the course of the work. 



The mean result obtained from many tests on solutions of varying 

 strengths and prepared from both solutions is that a leak of one 

 .scale division per minute, ten minutes after the emanation has entered 

 the ionisation vessel corresponds to 280 X 10"^^ gm. radium per 

 litre. 



Discussion of the Results. 



It is interesting to compare the results obtained in this work 

 with the radioactivity of some of the chief European and American 

 springs. 



One of the most radioactive waters known in the world is the 

 Quelle am Schweitzergang at Joachimsthal, Bohemia, in the neigh- 

 bourhood of which the pitchblende, that has constituted the chief 

 European source of radium, is mined. The value found for the 

 radium emanation content of the water of this spring is approximately 

 70,000 X 10" curie per litre, while the radioactivity of most Canadian 

 waters is only about one seven hundredth of this amount. On com- 

 paring them with the values obtained by Sir William Ramsay for the 

 Bath Springs in England, the difference is not quite so great except 

 as regards the amount of radium salts in the waters. The Kings 

 Well at Bath gave the relatively high value of 138-7 X 10"^^ gm. 

 radium per litre while the highest value found for any of the Canadian 

 waters was 46 X 10"*^ (Philudor Spring, St. Hyacinthe). 



This value is an exception, the average amount being about 

 3 X 10" , a value only slightly greater than has been found for sea 

 water, e.g., 1 X 10"^^ gm. radium per litre. 



In the United States no group of springs has been more fully 

 examined than that at Saratoga, New York State and complete 

 results of the radioactivity of the waters and gases evolved from the 

 springs have been published. Some of the results are included in the 



