Bush,[48] in a series of tests on each of 15 men in several different psychic fields found the following conditions among smoking students immediately after the period of smoking was completed: 1. A 10½ per cent. decrease in mental efficiency. 2. The greatest actual loss was in the field of imagery, 22 per cent. 3. The three greatest losses were in the fields of imagery, perception and association. 4. The greatest loss, in these experiments, occurred with cigarets. Bush ascribed these effects to pyridin, claiming that his experiments failed to reveal nicotin in the tobacco smoke, except in a very small proportion in that of cigarets. Tests for nicotin in smoke are beset with many difficulties and possible fallacies which have in the past misled investigators into apparently determining that tobacco smoke contained no nicotin, but simply decomposition products. Pyridin is unquestionably present in tobacco smoke, and is a poisonous substance, although less so than nicotin. It is not found, however, in chewing tobacco, and as the clinical effects of chewing tobacco are apparently identical with those of smoking tobacco, very strong and universally accepted chemical proof of the absence of nicotin from tobacco smoke must be awaited before accepting such a conclusion. (See([41]), ([42]), ([43]) in bibliography.) Cigaret smoking is a time waster; that is, it breaks up the power of attention, as few smokers are satisfied with one cigaret and the mere physical act of lighting a fresh cigaret disturbs the continuity of thought and work. Dr. W. J. Mayo[49] calls attention to the fact that according to his observations research scholars who smoke cigarets have not done well. [Sidenote: Insurance Experience on Tobacco Smokers] Only one insurance company, the New England Mutual,[50] has published any experience on tobacco users. This covered a period of 60 years and a body of 180,000 policyholders, as follows: RATIO OF ACTUAL TO EXPECTED MORTALITY.[M] ------------------------------------------------------- ABSTAINERS. | RARELY USE. | TEMPERATE. | MODERATE. --------------|-------------|------------|------------- Tobacco, 59% | 71% | 84% | 93% Alcohol, 57% | 72% | 84% | 125% ------------------------------------------------------- [M] The standard here used is the American Experience Table, which is largely an artificial table upon which premiums are based, but which provides for a much higher mortality than the average companies sustain. For example, the actual mortality of the New England Mutual in 1913 was 57 per cent. of the expected. [Sidenote: Interpretation] Fifty-nine per cent. of the expected mortality means that where, according to the premium tables, 100 were expected to die, only 59 actually died.