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practitioners who are unfamiliar with modern work on precipitation tests. The personal experience of the writer extending over some years is in complete agreement with the results recorded at the last two Serological Congresses held under the auspices of the League of Nations at Copenhagen and Montevideo, at both of which the superiority of the Kahn test over the best of the Wassermann techniques used was clearly shown. All the difficulties of the Wassermann test are magnified many times by conditions of work in the tropics and the disparity between the two tests must thus become still greater in favour of the method employing fewer variables. A not inconsiderable point is the cheapness of the Kahn test. The cost of guinea pigs for complement where a large number of Wassermann tests is carried out is great and with a contracted budget such points assume added importance. The antigen used was prepared at the Institute and has been standardized for potency against the antigen prepared by Messrs. Parke, Davis & Co. The test itself is carried out strictly according to the technique laid down by Professor Kahn.
EXAMINATION OF BLOOD SERA FOR SYPHILIS. EUROPEAN INDIAN CHINESE Total M. F. M. F. M. F. Strong positive 71 6 52 1 1,787 607 2,524 Positive 21 2 41 3 132 53 252 Weak positive 17 6 36 2 176 95 326 Doubtful 28 1 41 ... 315 148 563 Negative 312 44 174 3 1,333 632 2,498 Grand total 449 52 344 7 3,976 1,614 6,142(2) Agglutination Tests.-The method of qualitative receptor analysis has been continued in the case of the typhoid group; the method is extremely satisfactory provided care is taken in the preparation of the necessary antigens. B. typhosus may be seen to be the cause of the great majority of infections in Hong Kong.