Copy 1, Volume 1

Tracts on the natural history of animals and vegetables / Translated from the original Italian by John Graham Dalyell, with physiological illustrations by the translator.

  • Spallanzani, Lazzaro, 1729-1799
Date:
1803
Catalogue details

Licence: Public Domain Mark

Credit: Tracts on the natural history of animals and vegetables / Translated from the original Italian by John Graham Dalyell, with physiological illustrations by the translator. Source: Wellcome Collection.

    121/442 (page 25)
    animalcula? The infufliciency of fuch a fuppo- fition has already been feen. Neither ean heat impair the elafticity of the internal air : becaufe,: from the precautions taken, there was not the leaft difference between the ftate of the internal air and the external; and attending to what hap- pened on opening the veflels, fo far from that within being lefs elaftic, it is even more fo than’ the other. It is impoffible: to conceive the en- creafed elafticity is prejudicial to the origin of our animalcula, as 1 have feen them where the air was condenfed twice or three times more than its natural ftate. The conclufion will-then fub- fit, that when the higher clafs does not appear, it is becaufe heat has vitiated or injured the pro- ductive principle. The force of this conclufion: will afterwards be better comprehended... The fecond confequence is the inverfe of the firft, and refpeéts the conftancy or rather certainty of animalcula appearing in boiled clofe infufions. And this refult is no more favourable to the rea- fon afligned for none originating in infufions boiled an hour, becaufe too great heat had def- troyed the vegetative power, or impaired the elafticity of the air; nor with the time I ought to expofe infufions to heat, and {till fee animal- cula,-which has been preferibed to be as much as will deftroy the eggs of the filk-worm-moth, that is, 135°, or 138°, or 140°, the fame as we fhall feon