23 AUGUST 1957, Page 16

SIR,—Pharos says that the statistical evidence of 3 causal relationship

between smoking and lung cancer 'shows internal inconsistencies'; of course it &es: that seems to be inherent in the nature of the universe in which we live. It is not, however, a sound reason for denying that heavy cigarette smoking leads to the development of cancer of the lung in some people: the inconsistency lies in the fact that by no means all heavy cigarette smokers develop the disease, but not all persons exposed to benzol devt loP aplastic anemia—the causal relationship is, however, indisputable.

The special pleading that leads to such suggestions as that 'smoking and lung cancer are both diseases arising out of some deeper cause' is palpable non' sense: lung cancer does occur in some people 0° have never smoked. Must we then assume that there is not a single 'deeper cause' but that there are at least two, which may occur together or apart: if so, we shall have to suppose that these deePet causes never occur together in members of those Puritan sects to whom smoking is anathema. And a biologically interesting supposition—that the deeper cause that leads to smoking only arose in country after the introduction of tobacco.—Yours faithfully, 152 Harley Street, WI [Pharos writes: 'If Dr. Piney reads the Al' P letter 1' referred to in the HMI he will see that the ineon: sistency he mentions is only one of several—and 01 the most significant.'—Editor, Spectator.]