Page:Popular Science Monthly Volume 83.djvu/555

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551
ALCOHOL FROM A SCIENTIFIC POINT OF VIEW

mated that 6 grams of pure alcohol for each kilogram of body weight is a lethal or killing amount when injected into the stomach of an animal.

This was the beginning of quantitative work to which a few years later Dujardin-Beaumetz and Audigé added a brilliant series of experiments. They studied not only the toxicity of ethyl alcohol, but also that of other alcohols as well. Briefly stated, the question that they proposed to themselves was: How much alcohol is necessary to kill a kilogram of living matter in less than thirty-six hours?

If, for example, in studying the toxicity of alcohol, we find that 77.5 grams of alcohol injected into the stomach of an animal of 10 kilograms weight produces death in less than 36 hours, the question then as to the amount necessary to kill per kilogram is easily determined, for if 77.5 grams kill the entire 10 kilograms, 7.75 grams is the amount necessary to kill per kilogram. This, in fact, was the amount of ethyl alcohol found by them to be the lethal dose. This amount, however, is considerably below the estimate of 6 grams by Lussana and Albertoni. This difference in amount may be explained in part by the difference in the time limit employed; for while 6 grams may eventually kill, 7.75 grams is necessary to kill within a limited period of thirty-six hours.

For the coefficient of toxicity of the higher alcohols, Dujardin-Beaumetz and Audigé found the following values: For propyl, the member of the series just above ethyl, 3.75 grams per kilogram; for butyl 1.85, and for amyl 1.50 to 1.60 grams per kilogram body weight.

The molecular weight, boiling point and relative toxicity of the alcohols of fermentation are briefly summarized in the following table:

 
Alcohol Molecular Weight Boiling Point[1] Relative Toxicity
Ethyl 46 78° C. 7.75 gr. per kg.
Propyl 60 97.0° C. 3.75 gr. per kg.
Butyl 74 117.0° C. 1.85 gr. per kg.
Amyl 88 138.0° C. 1.50 to 1.60 gr. per kg.
 

From this table it is to be seen that the higher the molecular weight and boiling point, the smaller is the amount required to kill a kilogram of living matter. In other words, the higher an alcohol is in molecular weight and boiling point, the greater is its toxicity. This, as we have seen, is the law of Rabuteau with which the above facts of experiment are in direct accord.

In a study of methyl alcohol, on the other hand, Dujardin-Beaumetz and Audigé concluded that the toxicity is not in keeping with the law of Rabuteau. Though methyl alcohol has a molecular weight of 32 and a point of ebullition of about 66° C.—in both lower than ethyl alcohol—yet its toxicity was found by them to be greater—7 grams

  1. The boiling points are taken from Meyer and Jacobson's "Lehrbuch der organischen Chemie," Bd. I., 1906, p. 209.