BULLETIN 
OF THE 
MATHEMATICAL SECTION. 
24TH MEETING. FrEepruary 16, 1887. 
The Chairman, Mr. Wn. B. Taytor, presided. 
Present, eighteen members and one guest. 
The Section proceeded to the election of officers for 1887 by ap- 
pointing a Nominating Committee consisting of Messrs. FARQUHAR, 
Baker, and HI. 
The Committee nominated Mr. Wm. B. Taytor for Chairman 
and Mr. R.S.Woopwarp for Secretary ; these nominees were elected 
by acclamation. 
Mr. M. H. Doo.itt_eE read a paper on 
ASSOCIATION RATIOS. 
[Abstract. ] 
The present communication is an effort in the direction of a 
science of statistics. It includes the principles involved in my 
communication* of December 3, 1884, but presents them in a more 
general manner. 
Suppose that there are s occasions on which the presence or ab- 
sence of the phenomena A and B are determined by observation. 
Suppose that there are a instances of the occurrence of A, and } 
instances of the occurrence of B, each including ¢ instances in which 
A is associated with B. There remain s—a—6- ¢ instances in 
which A and B are both absent. If a—6 =e, the two phenomena 
are always found associated, and the association may be regarded 
as perfect. If either A or B is ever found alone, the association is 
*The verification of predictions. See Bulletin of Phil. Soc. for 1884, 
vol. 8, pp. 122-127. 
(83) 
