228 



SCIENCE 



[N. S. Vol. XLIX, No. 1262 



The figures given under Tli D are based 

 upon the amount of radiothorium which ac- 

 cumulates in mesothorium, and it is this prod- 

 uct which also measures the alpha-ray activity 

 of mesothorium. It is evident from the fig- 

 ures given under Th D that the alpha-ray 

 activity of pure mesothorium reaches a max- 

 imum between the fourth and fifth year after 

 its preparation and, further, that it is less 

 than 60 per cent. " aged " one year after prep- 

 aration. In spite of the fact that commercial 

 mesothorimn owes a proportion — probably 20 

 per cent. — of its activity to the presence of 

 radium, it follows that it would be uneco- 

 nomical to use mesothorium in luaninous com- 

 pound until it had aged for a year or two. It 

 seems evident that the small supply available, 

 the varying activity and the necessity for pro- 

 longed aging of mesothorium. are some of the 

 reasons that make this material less desirable 

 than radium, both for medical purposes and 

 in luminous compound, especially with an as- 

 sured supply of radium wholly adequate for 

 both requirements. 



Charles H. Viol 



Pittsburgh, Pa. 



STATISTICAL STUDY OF THE 

 INFLUENZA EPIDEMIC 



' The American Public Health Association, 

 Vital Statistics Section, appointed a Commit- 

 tee on Statistical Study of the Influenza Epi- 

 demic on IvTovember 20, 1918. Under the aus- 

 pices of this committee, a meeting of the state 

 and municipal registrars in the eastern states 

 was held at the University of Pennsylvania, 

 Hygiene Laboratory, Philadelphia, Pa., on ITo- 

 vember 29 and 30, 1918. There were present, 

 also, at this initial conference, several private 

 statisticians interested in the public health 

 statistics of the epidemic and the results to be 

 derived from study of such data. A series of 

 suggestions was made up, mimeographed and 

 sent to statistical and public health workers 

 for criticism. At the meeting of the Vital Sta- 

 tistics Section in Chicago on December 11, the 

 committee submitted a report on its activities 

 and asked for authority to continue further in- 

 quiry into a program of statistical study of 



the epidemic. The section authorized the con- 

 tinuance of the committee and provided that 

 representatives of the United States Bureau of 

 the Census, of the United States Army and 

 JSTavy, of the United States Public Health 

 Service, of the state and municipal health 

 boards, and the various statistical, sociological, 

 actuarial and economic associations be repre- 

 sented thereon. The committee was specifically 

 authorized to act in an advisory capacity first, 

 to outline the various sources of data, the 

 minimum standards of tabular and registra- 

 tion practises to be observed by the several 

 organizations providing data, and second, to 

 bring in recommendations on the pathometric 

 or mathematical analysis of published epidemic 

 data. The committee was divided into four 

 subcommittees as follows: 



Subcommittee A: Registration and Taiula- 

 tion Practise of the Federal Departments. 

 (Wm. H. Davis, M.D., chief statistician, Di- 

 vision of Vital Statistics, Bureau of the Cen- 

 sus, Chairman; Richard C. Lappin, Recorder.) 



Subcommittee B : Registration and Tahula- 

 tion Practise of the State Departments and 

 Commissions. (Otto E. Eichel, M.D., director, 

 Division of Vital Statistics, New York State 

 Department of Health, Albany, Chairman; 

 Edwin W. Kopf, Recorder.) 



Subcommittee C : Registration and Tabula- 

 tion Practise of Municipal Boards of Health 

 and of Private Public Health Agencies. Chas. 

 Scott Miller, M.D., Philadelphia Department 

 of Health, Philadelphia, Pa., Chairman.) 



Subcommittee D: Pathometry (mathemat- 

 ical analysis and interpretation) of the Epi- 

 demic. (Charles C. Grove, Ph.D., Columbia 

 University, Chairman; Arne Fisher, F.S.S., 

 Recorder.) 



Mr. E. "W. Kopf was delegated to act as 

 chairman of the General Committee and to 

 coordinate the work of the several subcommit- 

 tees. The General Committee of the Vital Sta- 

 tistics Section was authorized to cooperate in 

 statistical matters with the Influenza Refer- 

 ence Committee of the entire association."- 



1 See "Influenza Bulletin." American Public 

 Health Association, Boston, December 13, 1918. 



