Page:Aspects of nature in different lands and different climates; with scientific elucidations (IA b29329668 0002).pdf/54

 *[Footnote: stricter criticism, has been the subject of much animated discussion. Baker affirmed that he had resuscitated, in 1771, paste-eels which Needham had given him in 1744! Franz Bauer saw his Vibrio tritici, which had been dried up for four years, move again on being moistened. An extremely careful and experienced observer, Doyère, in his Mémoire sur les Tardigrades, et sur leur propriété de revenir à la vie (1842), draws from his own fine experiments the following conclusions:—Rotiferæ come to life, i. e. pass from a motionless state to a state of motion, after having been exposed to temperatures of 19°.2 Reaumur below, and 36° Reaumur above, the freezing point; i. e. from 11°.2 to 113°.0 Fah. They preserve the capability of apparent revivification, in dry sand, up to 56°.4 R. (158°.9 Fah.); but they lose it, and cannot be excited afresh, if heated in moist sand to 44° only (131°.0 Fah.) Doyère, p. 119. The possibility of revivification or reanimation is not prevented by their being placed for twenty-eight days in barometer tubes in vacuo, or even by the application of chloride of lime or sulphuric acid (pp. 130-133). Doyère has also seen the rotiferæ come to life again very slowly after being dried without sand (desséchés à nu), which Spallanzani had denied (pp. 117 and 129). "Toute dessiccation faite à la température ordinaire pourroit souffrir des objections auxquelles l'emploi du vide sec n'eût peut-être pas complètement repondu: mais en voyant les Tardigrades périr irrévocablement à une température de 44°, si leurs tissus sont pénétrés d'eau, tandis que desséchés ils supportent sans périr une chaleur qu'on peut évaluer a 96°]*