V.—MANIFOLD CLASSIFICATION, (1768)2/1169 26739 (946)%/1303 686-8 (115)2%/357 37-0 (807)2/1088 5986 (1387)%/1212 1587-3 (438)%/332 577-8 (189)2/506 706 (746)%/563 988-5 (288)%/154 5386 (47)%/48°0 46-0 53)%/534 526 16)2/14-6 17-5 Total= = 78752 I. 6800 -—- = 1075-2 i 10752 EEE (1. The squares in such work may conveniently be taken from Barlow’s Zables of Squares, Cubes, etc. (see list of tables on P- iy or opi a9 be used throughout—five figure ogarithms are quite sufficient. 9. While such a coefficient of contingency, in some form or other, is a great convenience in many fields of work, its use should not lead to a neglect of those details which a treatment by the elementary methods of § 4 would have revealed. Whether the coefficient be calculated or no, every table should always be examined with care to see if it exhibit any apparently significant peculiarities in the distribution of frequency, e.g. in the associa- tions subsisting between 4,, and B, in limited universes. A good deal of caution must be used in order not to be misled by casual irregularities due to paucity of observations in some compartments of the table, but important points that would otherwise be over- looked will often be revealed by such a detailed examination. 10. Suppose, for example, that any four adjacent frequencies, say— (4,.B.,) (Ams Bn) I. (441Bns1) are extracted from the general contingency table. Considering these as a table exhibiting the association between 4, and 2B, in a universe limited to. 4.4.41 BoB alone, the association is positive, negative, or zero according as (4,,8,)/(4d,,+1B,) is greater 67