12 FEBRUARY 1960, Page 17

DEVIL'S WORK SIR.—Diabolus typographicus has been at work in the

very kind, indeed flattering, review of the third volume of Science and Civilisation in China in your issue for January 22. Though loth to disappoint the more mystical of your readers, we feel moved to point out that Chapter 25 concerns not 'Numerology' but 'Mineralogy.' The scientific men of medieval China had many interesting things to say about rocks and ores. It is true that some of them were also favourably inclined, like the Kabbalists of the Western world, to a fanciful play with numbers re- garded as symbols rather than as measures of empiri- cal plurality; but this had already been described in the second volume (Chapter 13, pp. 268 ff., 287 ff.). It did not detract from their genuine scientific achieve- ments, which were numerous, and which we are seeking to make better known.—Yours faithfully,