D. T. Barry, F. R. C. S. and M. D. of the Physiological Department, University College, Cork, is not very far off when he writes: “The physiological effects of tobacco, as our present knowledge reveals them, are not sufficiently deleterious to counter-balance the benign influence of the drug in other respects. It may be abused, of course, but so may food, and this latter form of abuse is, in my opinion, responsible for greater evils than those resulting from the abuse of tobacco.” In this connection another authority, Armstrong-Jones, remarks that tobacco smoking in moderation is not injurious to adults but is a valuable sedative. It contributes to calm thought and efficient mental functioning. Worst of all he casually remarks that cigarette smoking, preferably without a holder, is the least injurious form of tobacco indulgence. Even allowing for the fact that the gentleman has seen some of the less comely holders I have witnessed in my time, his statements give pause. Of course Earp’s well-known studies at Antioch College, Ohio, did indicate that non-smokers showed an intellectual superiority over smokers, but whether these things were cause and effect or mere harmless concomitants who knows? Many very eminent intellectual giants smoked excessively. Perhaps they would have achieved absolute omnipotence or omniscience had they been non-smokers. Again, who knows? It is significant that Earp’s non-smokers showed no physical superiority over his smokers; that is, it is interesting when you remember that the American university is an institution of athletic training wherein some intellectual education is offered to the feeble-bodied as a consolation prize. Intelligence tests are not affected by smoking, the non-smokers ranking just as high after smoking as before they had ever touched the vile weed. Finally, the correlation between the length of a student’s indulgence in tobacco and his scholarship is so negligible as to indicate that there can be no chronic cumulative poisoning from tobacco. Laymen do not realize how difficult it is to trace a diseased condition to a specific cause even when bacteria abound, as is not the case in smoking. For instance certain bacteria so closely resemble each other that even experts are hard put to tell them apart. Diphtheria germs possess such a dead ringer. Real diphtheria cultures were once sent out to clinical laboratories along with other cultures containing no diphtheria germs, but germs so closely resembling them that the laboratories involved returned all sorts of results. Some reported that the actual diphtheria cultures contained no diptheria germs at all; others that some of the germs simulating diphtheria in appearance were positively the real thing. So a tooth or a tonsil may contain a germ so similar to those found at the seat of secondary infection that they are indistinguishable, yet the germ may be harmless in one case and virulent in the other.