Decembeb 2, 1910] 



SCIENCE 



789 



be prepared and preserved. After some de- 

 liberation the committee was announced and 

 consisted of Mme. Curie and M. Debierne, for 

 France, Professors Rutherford and Soddy for 

 Great Britain, Professor Geitel and Dr. Hahn 

 for Germany, Professors St. ileyer and von 

 Schweidler for Austria, Professor Boltwood 

 for the United States and Professor Eve for 

 Canada. It is probable that representatives 

 of other countries who are willing to assist in 

 the work will be added later. An address was 

 then given by Mme. Curie on the subject of 

 her recent experiments on the preparation of 

 metallic radium. No formal action was taken 

 on the subject of nomenclature, but it was 

 agreed that the present system of nomen- 

 clature, though far from perfect, was to be 

 preferred to a possibly more rational system 

 which would involve a general change in the 

 names now given to the radioactive sub- 

 stances and would lead to much confusion, for 

 which the advantages obtained would scarcely 

 compensate. The present system affords op- 

 portunities for including new products which 

 may be later discovered. Thus, if future in- 

 vestigation should prove that the product 

 radium C is complex and consists of several 

 separate substances, these can be called 

 radium Cj, C,, etc., and the term radium C 

 can be retained for the mixture of the several 

 separate products which normally occur to- 

 gether. It was also suggested that the term 

 " half -value period " should be used to express 

 the time required for any given radioactive 

 'product to become haK transformed into 

 other substances and that the expression 

 " active deposit " should be used in place of 

 the terms " induced " and " excited " activity. 

 These proposals were received with general 

 approval. 



On the following day the congress met in 

 three sections in which a large number of in- 

 teresting papers on the physical and medical 

 aspects of radiology were presented. On the 

 last day so many important papers remained 

 to be read that it became necessary to sub- 

 divide the meetings still further and a sepa- 

 rate section was formed for the consideration 

 of purely radioactive questions. Unfortu- 



nately, the number of papers were so great 

 that by the system under which the meetings 

 were conducted, insufficient time was avail- 

 able for the proper presentation of a large 

 number of papers. In fact the general ar- 

 rangements for the meetings were not alto- 

 gether satisfactory and some dissatisfaction 

 was expressed at the close at the way in which 

 the affairs had been managed. From the 

 standpoint of general usefulness, however, the 

 congress was a great success as it afforded an 

 excellent opportunity to all who attended to 

 become acquainted with other workers in 

 their own special lines. The arrangements 

 for the time and place of the next congress 

 were placed in the hands of an international 

 committee and it is to be hoped that another 

 gathering can be effected in the near future. 

 The International Committee on Standards 

 reported at one of the last meetings and its 

 recommendations were formally adopted. The 

 substance of the report was as follows : 



1. lime. Curie has kindly agreed for the 

 purposes of the standard to prepare a quantity 

 of the purest obtainable anhydrous radium 

 chloride containing about 20 milligrams of 

 radium (element). 



2. When the committee has reimbursed 

 Mme. Curie for the cost of the radium stand- 

 ard, this will come under the control of the 

 committee and will be used only for the 

 measurement and comparisons of secondary 

 standards by means of the y-rays. The orig- 

 inal standard is to be suitably preserved and 

 deposited in Paris. 



3. Through the committee and at its dis- 

 cretion national scientific laboratories and 

 bureaus of standards willing to pay the costs 

 are to he provided with certified secondary 

 standards. 



• 4. By such methods as, after due consid- 

 eration, meet with the approval of the com- 

 mittee smaller subsidiary standards are to be 

 prepared for distribution. 



5. As radium emanation is now so generally 

 used in scientific investigations, the com- 

 mittee considers the adoption of a unit for the 

 measurement of the amounts of radium 

 emanation desirable. The committee recom- 



