December 2, 1910] 



SCIENCE 



791 



mately ten milligrams or so. A further mat- 

 ter which has to be considered is the prepara- 

 tion and distribution of extremely dilute 

 solutions of radium salts. For many scien- 

 tific purposes, such as the determination of the 

 radioactivity of natural waters and rocks, 

 standard solutions of radium containing a 

 definite, known amount of radium per cubic 

 centimeter are frequently required. The 

 committee proposes later to have prepared 

 imder its direction standard solutions of this 

 kind, the strengths of which are known in 

 terms of the primary standard. It will prob- 

 ably be some time before these solutions are 

 ready for distribution, and as it may be of 

 considerable assistance to workers in radio- 

 activity to have some working standard for 

 their present uses, the writer will be glad to 

 furnish to those who may now require it small 

 quantities of the solution prepared by Eve, 

 Rutherford and Boltwood.' The strength of 

 this solution is accurately known in terms of 

 the radium standard in the possession of Pro- 

 fessor Eutherford. When the new interna- 

 tional standard has been prepared, the 

 Eutherford standard will be compared with 

 this, and any results obtained by the use of 

 the present solution can then be corrected in 

 terms of the international standard. 



It is to be hoped that the International 

 Eadium Standards Committee, in its efforts 

 to place radioactive measurements on the 

 same accurate basis as electrical and other 

 . measurements, will be supported financially by 

 the governments of the countries represented. 

 All questions with regard to the international 

 radium standard should be addressed to Pro- 

 fessor Stefan Meyer, the secretary of the In- 

 ternational Committee, Institut fur Eadium- 

 forschung, Waisenhausgasse 3, Vienna IX., 

 Austria. Bertram B. Boltwood 



TEE CONVOCATION WEEK MEETING OF 



THE AMERICAN ASSOCIATION FOR THE 



ADVANCEMENT OF SCIENCE AND 



AFFILIATED SOCIETIES 



The sixty-second annual meeting of the 



Ajnerican Association will be held in llinne- 



»4m. Jour. Sci. (4), 22, 1, 1906. 



apolis from Tuesday, December 27, to Satur- 

 day, December 31. The first general session 

 will occur on Tuesday evening in connection 

 with the president's address, instead of in the 

 morning, as has been the custom. This is 

 made desirable by the fact that registration is 

 a day later than usual. Following the presi- 

 dent's address, a reception will be held in the 

 parlors of the Hotel Eadisson, the head- 

 quarters for the meeting. On Wednesday 

 evening, a public lecture will be given in Saint 

 Paul, complimentary to the citizens of that 

 city, and on Thursday evening a similar com- 

 plimentary lecture to the people of Minne- 

 apolis. The public meetings of Tuesday and 

 Thursday will be held in the auditorium of 

 the First Baptist Church, 10th Street and 

 Harmon Place, three blocks from the Hotel 

 Eadisson. A reception to visiting ladies will 

 be tendered by the Woman's Club on Thurs- 

 day afternoon. 



All sections, together with the afiiliated so- 

 cieties, will hold their meetings at the Uni- 

 versity of Minnesota. By request, the sessions 

 of certain sections will be held at the College 

 of Agriculture during one day of the meeting. 

 Dinners, smokers and other social functions 

 will be given in the Hotel Eadisson or in the 

 rooms of the Minneapolis Commercial Club, 

 which are in the same building. The Com- 

 mercial Club has arranged to furnish visitor's 

 cards to members as they register, and the 

 club rooms will be used as social headquarters 

 for the meeting. Luncheons will be furnished 

 on the university campus during the days of 

 the meeting. 



It is probable that railroad rates of one and 

 a third fare will be granted from eastern and 

 southern points to Chicago. In the middle 

 west, where a two-cent fare is almost uni- 

 versally in effect, there is no reduction. It 

 should be noted that the round-trip fare from 

 points east of Chicago will be at the rate of 

 one and a third on the three-cent basis. 



Secretaries of sections and of affiliated so- 

 cieties who desire to make reservations for 

 dinners or smokers or who wish to have special 

 facilities provided for meetings should write 

 the secretary of the local committee, Frederic 



