Scientific American. New Series, Volume 20, Issue 14, Apr 3, 1869
It appears that until 1864 the belief that there was nothing injurious in absinthe except the alcohol, was general enough. In that year, however, a mad doctor named Marce, communicated a paper to the Academy of Sciences, in which he demonstrated that the essence of wormwood was contained in the liquor called absinthe, in the proportion of twenty grammes of essence to 100 liters of alcohol, and argued that this essence had a peculiarly injurious effect on the brain.
In 1867 a petition was presented to the Senate, praying that the sale of absinthe might be absolutely forbidden. Nothing came of it; and now the question of absinthe has been once more brought forward by two physicians, MM. Magnan and Bouchereau, who, for the first time, have made regular scientific experiments with the questionable stuff. The object of the experimentalists was to show what the effect of pure alcohol would be on a guinea-pig, and what the effect of absinthe.
With this view, they placed a guinea-pig under a glass case, with a saucer full of essence of wormwood by his side, another guinea-pig being placed under another glass case with a saucer full of alcohol. The guinea-pig, who, so to say, was being treated with absinthe, sniffed at the fumes, and for a few moments seemed, like the ordinary absinthe drinker, supremely happy. Gradually, however, be became heavy and dull, and at last fell on his side, agitating his limbs convulsively, foaming at the mouth, and presenting all the signs of epilepsy. The same epileptic symptoms were manifested on the part of a cat and rabbit, who, in a similar manner, were made to inhale the fumes of absinthe.