Lehmann (Archiv für Hygiene, 1909, p. 319) found that from 80 to 90% of the total nicotine in a cigar or cigarette was to be found in the smoke. He found also that in the case of cigars about 10 to 18% of the nicotine in the smoke is absorbed by the smoker and that cigarette smoke absorbed by the smoker contains a less proportion of the nicotine in the tobacco than is the case with cigars. The general opinion is, however, that about one-seventh of the nicotine in the tobacco will be found in the smoke.
Entirely at variance with these results are those obtained recently by A. D. Bush, M.D., Instructor of Physiology in the University of Vermont (New York Medical Journal, March 14, 1914), and those obtained in the laboratory investigation by the London Laucet. Bush made long and extensive investigations on the effects of tobacco smoking and criticised the results of previous workers. He shows very clearly that in many cases the conclusions drawn by them as regards nicotine contained in tobacco smoke are either entirely erroneous or that the deductions made from the investigations were not warranted by the facts observed. He points out the fact that most writers on the subject have overlooked the fact of the great discrepancy between the possible effects arising from the administration of the amount of nicotine in a cigar and the actual effect produced on the smoker of the cigar. He asks this pertinent question: “If a cigar contains 0.085 grains nicotine, and if one-seventh of the nicotine of the tobacco is present in the smoke and if but .004 grains is capable of causing death, why does the smoker not absorb enough nicotine to cause his demise?”
As a result of his careful experiments, Bush found that although nicotine was present in all the samples of tobacco tested there was no nicotine whatever found in the smoke, except in the case of cigarettes and in this case only traces were found. The reason of this is given as due to the rapid burning of the cigarette which did not allow sufficient time for the complete decomposition of the nicotine. Pyridine was, however, found in the smoke of all tobacco burned. Pyridine is only one-twentieth as toxic as nicotine. Bush concluded, therefore, that pyridine and not nicotine is the toxic factor in tobacco smoke. The same fact was stated several years ago by Rideal (Disinfection and Preservation of Food, London and New York, 1903, p. 254), who says: “Tobacco smoke, contrary to popular belief, does not contain nicotine, which is decomposed by the heat; but pyridine and its homologues and the beneficial effects of tobacco in many cases of asthma must be attributed to this latter.”
The Lancet investigation (see Lancet, Ap. 6, 1912, pp. 944-947) was made because “a recent review of numerous analysis of tobacco which have been published from time to time raises some doubt as to whether the results given correctly represent the actual alkaloidal contents of the tobacco.” Moreover, to find the relationship of the true amount of nicotine in any tobacco to that in the smoke produced by the combustion of that tobacco, and any modification caused by the method of smoking.
The investigation was conducted under the strictest conditions, the most recent methods of chemical research being employed.
The following table (given by the Lancet) shows the nicotine contents of various tobacco samples and the percentage of nicotine in the smoke:
| Description of Tobacco. | Per Cent Nicotine in Tobacco | Per Cent Nicotine in Smoke (Pipe). | Per Cent Nicotine in Smoke (Cigarette). | ||||
| Virginian Cigarettes (Sample 1) | 1.40 | 0.74 | 0.12 | ||||
| Virginian Cigarettes (Sample 2) | 1.60 | 0.60 | 0.06 | ||||
| Caporal (French) Tobacco | 2.60 | 2.20 | 0.95 | ||||
| Turkish Cigarettes | 1.38 | .... | 0.51 | ||||
| Egyptian Cigarettes | 1.74 | .... | 0.21 | ||||
| Pipe Smoking Mixture (1) | 2.85 | 2.20 | 2.25 | ||||
| Pipe Smoking Mixture (2) | 2.81 | 1.53 | .... | ||||
| Pipe Smoking Mixture (3) | 2.04 | 0.23 | .... | ||||
| Perique Tobacco | 5.30 | 1.27 | 0.57 | ||||
| Cavendish Tobacco | 4.15 | 3.85 | .... | ||||
| Latakia Tobacco | 2.35 | 1.20 | .... | ||||
| Havana Cigar | 0.64 | .... | 0.20 |
From this analysis it appears that pipe mixtures contain the largest amount of nicotine in the tobacco (2.04-2.85%). Egyptian and Turkish cigarette tobaccos come next (1.38-1.74%). Virginian cigarette tobacco shows similar figures (1.40-1.60%). French tobacco (Caporal) contains 2.60%, and Perique 5.30%. For all practical purposes the tobaccos consumed by the public according to this report seldom contain more than 3% of nicotine and generally less, the average being about 2%, which is much lower than previous writers lead us to expect.
The cigarette, whether Egyptian, Turkish or American, yields the least amount of its total nicotine to the smoke formed, while the pipe yields a very large portion (in some cases between 70 and 80%) of its nicotine to the smoke. Analysis of cigar smoke gives figures midway between the two.